ISSN 2185-159X

erd

International Journal ofEnvironmental and Rural Development

Volume 10 Number 2

December 2019

International Society of Environmental and Rural Development

IJERD – International Journal of Environmental and Rural Development

erdInternational Journal ofEnvironmental and Rural Development
Official Journal of the International Society of Environmental and Rural Development(Accessible from J-Stage, EBSCO, Google Scholar, CABI International, etc.)

Aims and Scope:
The International Journal of Environmental and Rural Development, IJERD, is an interdisciplinary journal
concerning environmental and rural development research in the education for sustainable development, ESD.
The IJERD is devoted to publishing peer-reviewed research article, review article and technical report in thefields of environmental and rural development, such as education for sustainable rural development, ruraldevelopment, environmental management or agricultural systems. Every article or report in IJERD must be
accepted by at least 2 reviewers and an editorial member.
The aims of IJERD are to publish the latest research development and achievements, to strengthen
education systems, to promote cooperation in environmental and rural development and to contribute to theprogress in sustainable development. The editorial board of this journal covers a variety of scientificdisciplines.
Thematic Areas:
The following areas are envisioned in IJERD.
Education for Sustainable Rural Development:
Environmental Education, Food and Agricultural Education, Participatory Approach, Capacity Building,Community Empowerment, Agricultural Extension, etc.
Rural Development:
Marketing, Partnership, Value Added Product, Community Development, Access to Technology,
Cultural Preservation, etc.
Environmental Management:
Bio-Diversity, Soil Degradation and Land Conservation, Water Quality Conservation, Deforestation andSustainable Forest Management, Environmental Management, etc.
Agricultural Systems:
Organic Farming, Conservation Tillage, Mechanization, Irrigation and Drainage, Nutrient and Pest
Management, Cattle Breeding, Agro-Forestry, Indigenous Technology, etc.
Infrastructural Systems:
Water Resource Development, Land Reclamation, Road Construction, etc.
Editorial Board:
Editor in Chief:
Prof. Dr. Machito Mihara, Tokyo University of Agriculture, Japan /Institute of Environmental Rehabilitation and Conservation, Japan
Managing Editors:
Dr. Jeeranuch Sakkhamduang, Institute of Environmental Rehabilitation and Conservation,
Southeast Asia Office / Association of Environmental and Rural Development, Thailand
Dr. Junaid Alam Memon, Pakistan Institute of Development Economics, Pakistan
Dr. Shinobu Terauchi, Institute of Environmental Rehabilitation and Conservation, Japan
Dr. Toru Nakajima, Tokyo University of Agriculture, Japan
Editorial Advisory Board:
Prof. Dr. Mom Seng, Royal University of Agriculture, Cambodia
Dr. Insa Kuhling, University of Applied Sciences, Germany
Dr. Carlos Onan Tovar Mendoza, Honduras Embassy in Japan, HondurasProf. Dr. Noureddin Driouech, Mediterranean Agronomic Institute of Bari, Italy
Prof. Dr. Kiichiro Hayashi, Nagoya University, Japan
Prof. Dr. Kingshuk Roy, Nihon University, Japan
Dr. Yuri Yamazaki, Tokyo University of Agriculture, Japan
Prof. Dr. Merites M. Buot, University of the Philippines Los Baños, Laguna, Philippines /UP Open University, Philippines
Prof. Dr. Salvador Catello, University of the Philippines, Philippines

IJERD – International Journal of Environmental and Rural Development

Prof. Tomas Reyes, Jr. Bohol Island State University, Philippines
Dr. Julian Torillo, Jr. Bohol Island State University, Philippines
Dr. Venkatachalam Anbumozhi, International Centre for Trade and Sustainable Development,
Switzerland
Dr. Anchasa Pramuanjaroenkij, Kasetsart University, Thailand
Prof. Dr. Rajendra P. Shrestha, Asian Institute of Technology, Thailand
Dr. Somsak Srisontisuk, Khon Kaen University, Thailand
Dr. Vidhaya Trelo-Ges, Khon Kaen University, Thailand
Prof. Dr. Vo Quang Minh, Cantho University, Vietnam
Editorial Section in ISERD Secretariat:
Dr. Shinobu Terauchi and Dr. Takashi Ueno
Research Center, Institute of Environmental Rehabilitation and Conservation (ERECON)
2987-1 Onoji Machida-Shi, Tokyo 195-0064, Japan
Tel/Fax: +81-42736-8972
E-mail: iserd.secretariat@gmail.com
Webpage: www.iserd.net
Collaborated with

Association of Environmental and Rural Development (AERD)
93/64 Moo.3, Sinsab Village 2, Bungyeetho Sub-district, Thanyaburi District,Pathum Thani 12130, Thailand
Tel/Fax: +66-2957-8064
E-mail: iserd.secretariat@gmail.com
Webpage: www.iserd.net

IJERD – International Journal of Environmental and Rural Development (2019) 10-2

Contents
Humanitarian Assistance to Decreasing Vulnerabity in Flood-Prone Village: A Case Studyin Boeung Leas Village, Steung Sen District, Kampong Thom Province, Cambodia
Jun Fujihira, Bunthea Ly, Thome Xaisongkham,
Veasna Prom and Erika Inoue

1

Properties of Lightweight Concrete Using Expanded Polystyrene as Aggregate
Eiji Matsuo

8

An Assessment of Soil Chemical Properties and Yields of Black Gram, Using GIS,
in a Selected Area of Myanmar
Htay Htay Oo, Khin Mar Oo, Swe Swe Mar
and Naing Naing Moe

14

The Spatial Variability of Soil Chemical Properties in a Selected Area of Myanmar
Naing Naing Moe, Swe Swe Mar, Aung Kyaw Myint, Kyi Toe
and Kyaw Ngwe

20

Participatory Risk Assessment of Nong Han Wetland, Thailand
Prajya Ngamjan and Thodsapol Chaturabul

27

Development of Ecotourism in North Bandung, Indonesia
Faridah Siti and Eiji Yamaji

34

Performance Analysis of 325 kW Solar PV Rooftop System Using PVsyst Program
Pakaykaew Boottaraja and Napaporn Phuangpornpitak

40

Erosion Control and Slope Stabilization for Loose Sandy Soil by Using Vetiver Grass
Piyanuch Jaikaew and Kongrat Nokkaew

46

Comparative Study on 3 Rice Farming Systems: Conventional, Partially Organic, and Organic
Farming, Case Study in Prey Kabbas District, Takeo, Cambodia
Sereiroth Bunthan and Yamada Ryuichi

54

Physical and Chemical Properties of Compost Made from Agricultural Wastes
Thidar Khaing, Suu Suu Win and Nyo Nyo Win

61

Effect of Long-Term Rubber Tree Plantation on Soil Properties Comparing to Sugarcane Plantationin Khon Kaen, Thailand
Xaysatith Souliyavongsa, Vidhaya Trelo-Ges,
Supat Isarangkool Na Ayutthaya, Christian Hartmann andAlain Pierret67

A Comparative Study of Economic Efficiency Between Small and Medium Size Rubber Plantationin Thbong Khmom Province
Keovorleak Vichet and Tomohiro Uchiyama

73

Factors Affecting Farmers` Decision on Crops Selection with Special Reference to New Technology:
Case of Sunflower Seed and Sweet Potato in Ikungi District, Tanzania
Rubasha Matiku Mujama and Yoichi Izumida

80

Content of Online Marketing that Influence Customers` Decision: A Case on Buying Indigo-Dyed
Clothing
Saranya Saetang

86

The Impact of Agricultural Export Product on Income and Employment in the Thai Economy
Anucha Wittayakorn-Puripunpinyoo

91i

IJERD – International Journal of Environmental and Rural Development (2019) 10-2Comparative Study on Pulse Production with Different Practices: A Case Study of Mungbean andBlack Gram
Khin Mar Oo, Htay Htay Oo, Nyein Nyein Htwe and Hla Than

97

Determination of Physicochemical Properties and Characterization of Soil from Gold Mining Areasof Kachin State, Myanmar
Moe Tin Khaing and Hla San Win

104

Functional Evaluation of Groundwater Level Decrease in Non-sloped Subsurface Drainage Systems in
Upland Field on Peatland
Naho Nohara, MinoruYokochi, Tadao Yamamoto
and Takashi Inoue

110

Identifying the Minimum Number of Observed Rainfall Events Required for Optimal TOPMODEL
Parameters in Mid-sized Equatorial Catchments
Emmanuel Okiria, Hiromu Okazawa, Yuri Yamazaki
Yukimitsu Kobayashi and Shinji Suzuki

117

Effects of Earthworm Megascolicidae Population and Litter Quantity on Soil Properties
in Experimental Containers
Takanori Kaneko, Tomonori Fujikawa and Machito Mihara

125

Ecotourism-related Strategies toward Increasing Tourism Destination Competitiveness:
The Case of Biliran Island Province
Venice B. Ibañez

132

GIS-based Analysis for the Energy Potential and Social Feasibility of Small-Scale Run-Off-River
Hydropower in Yahagi River, Japan
Yuri Yamazaki, Kiichiro Hayashi, Nobuko Kawaguchi,
Hiromu Okazawa and Ferdinando Villa

138

Farming Practices Assessment and Economic Analysis of Organic Rice Farming in Cambodia:
Case Study of a Commune in Preah Vihear Province
Chanmony Sok, Tomohiro Uchiyama and Nina N. Shimoguchi

146

Economic Performance of Using Combine Harvesters in Rice Cultivation in Northwest Cambodia
Dalin Sun, Tomohiro Uchiyama and Nina N. Shimoguchi

152

Developing of Incinerator with Hydrogen Gas for Hospital Wastes Treatment
Kitichoke Prommaneewat and Supalak Sathiracheewin

158

Physicochemicals Properties of Soils with Peanut Shell Amendment and Its Impact to Growthand Yield of Maize
Nyo Nyo Win, Thidar Khaing and Suu Suu Win

164

The Stream Flow and Water Level Change on Mekong Mainstream fromthe Hydropower Development Projects at Nakhon Panom, Thailand
Thodsapol Chaturabul, Thanaporn Supriyasilp
and Kobkiat Pongput

170

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

Research article
erd

Humanitarian Assistance to Decreasing Vulnerabity inFlood-Prone Village: A Case Study in Boeung Leas Village,
Steung Sen District, Kampong Thom Province, Cambodia
JUN FUJIHIRA*
University of Extremadura, Caceres, Spain
Email: junjohnjun@gmail.com

BUNTHEA LY
Youth Resource Development Program, Phnom Penh, Cambodia
Email: bunthealypeace@gmail.com

THOME XAISONGKHAM
Oxfam International, Vientiane, Lao PDR
Email: thome.xaisongkham@oxfam.org

VEASNA PROM
Heifer International Cambodia, Phnom Penh, Cambodia
Email: Veasna.Prom@heifer.org

ERIKA INOUE
Ateneo de Manila University, Manila, Philippines
Email: joliepoupee19@gmail.com
Received 8 January 2019

Accepted 7 April 2019(*Corresponding Author)

Abstract Flood is the most severe disaster in Cambodia because the country locates in theflood plain region. To tackle this national challenge, the Cambodian government has beendeveloping policies and programs on disaster risk reduction. For supporting disasteraffected populations, various organizations provide humanitarian assistance before andafter the disaster. However, due to country’s vulnerabilities, a number of Cambodians still
suffer from floods, such as food insecurity and health problems. To decrease its
vulnerabilities, community should build community resilience through build back betterbased on their past experiences, while receiving humanitarian assistance to enhance theircapitals. As women are among the most vulnerable victims in post-flood situation, thestudy tried to understand existing major community capitals as well as gaps between
humanitarian assistance and needs of vulnerable women. Totally 53 people consist from 33
female villagers and 20 key informants mixture of male and female were selected as
respondents for Focal Group Discussions (FGDs) and Key Informants Interviews (KIIs)
through purposive and snowball sampling approaches based on their status and experiences.
The study concluded that humanitarian actors better to focus more on activities to enhanceinsufficient physical, natural, and financial capitals of the village for decreasing existing
vulnerabilities including poverty, weak governance, and insufficient local structure fordisaster risk reduction by applying Build Back Better approach, which build resilience ofvulnerable areas based on past experiences and impacts.
Keywords community resilience, vulnerability, humanitarian assistance, build back better

INTRODUCTION
Cambodia has a tropical monsoon climate and is known as one of the most disaster-prone countries
in the world. United Nations Development Programme (UNDP) (2012) reported that 53% of 2,050
disaster-related deaths between 1996 and 2011 were caused by flood in Cambodia. Women areⒸ ISERD

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

among the most vulnerable groups without their participation opportunities to share theirexperiences and needs in decision-making process of authorities. Even though the Cambodian
government has policies and programs on disaster risk reduction, villages still have vulnerabilities
to hamper community resilience. Vulnerability normally generated due to insufficient capacity for
preparation, response, adaptation, resistance, and recovery from hazard impact (Winsner et al.,2004). As Human Policy Group (2006) specified that disasters are caused by human vulnerabilities
rather than hazard per se, decreasing vulnerability is a key to reduce disaster impacts. According to
Sendai Framework (2015), identification of vulnerability is essential for proper humanitarianassistance. It is because that vulnerability will be decreased when the community improve theircapacity to cope with disasters because these two factors are interrelated (Cannon et al., n.d.).
Humanitarian assistance aims at lifesaving and damage alleviation during and after disasters,
as well as strengthening preparedness for future hazard (Development Initiatives, n.d.). Ideal
humanitarian assistances decrease vulnerability while promoting community resilience andcapacity to mitigate impacts of future hazard. From this point, Build Back Better is one ofappropriate approach for humanitarian assistance because it is an process to improve resilience andcapacity of the disaster-affected communities, while reducing their vulnerability based on theirexperiences (Mannakkara and Wilkinson, 2015). Schilderman (2010) also specified that theexperience with owner-driven reconstruction has been more positive than with donor-driven
reconstruction.
Therefore, this paper attempts to analyze existing community’s five-capital as well as gaps
between emergency response and needs of vulnerable women to decrease vulnerability in Boeung
Leas village.
MATERIALS AND METHODS
Study Site
Study site is the Boeung Leas village, which is the one of four villages in Ou Kantor commune in
Steung Sen district in Kampong Thom province, Cambodia (Fig 1). The village has 130.89 hectaresof land with 88 households with population of 354 including 182 females. Main income resourcesof the residents are fishery, rice production and harvesting naturally grown morning glory(Ipomoea aquatica) because the village has big lake in the southern part of village, which stream
from the Tonle Sap Lake. Due to its location in low terrain near Steung Sen River and Tonle Sap
Lake, the village is the most vulnerable village to regular flood among four neighboring villages.
Especially southern part of the village suffers from severe flood impact annually. Chronic impactof severe floods and droughts in whole year make the villagers poor. In 2015, 33% of households
in the village recognized as poor and received the recognition paper for the poor by provincial
government.

Steung Sen district

Lake

Fig. 1 Map of flood affected households and Boeung Leas village in Kampong Thom provinceⒸ ISERD

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

Data Collection and Analysis
By aiming at understanding existing major community capitals as well as gaps between emergency
response and needs of vulnerable women to decrease vulnerabilities in village, the study applied
focus group discussions (FGDs) and key informant interviews (KIIs). The study collected datafrom total 53 samples consist from 33 female villagers, nine members of the Disaster Management
Committee in the commune, and 11 key informants who involved in the humanitarian assistance.
All samples were purposively selected applying snowball sampling approaches based on theirstatus and experiences. Align with recommendation of Dworkin (2012) for 25-30 participants forin-depth interviews, 33 women which covers 18.13% of female villagers were selected for three
FGDs. Men were intentionally excluded to avoid interruption and dominant on answers. Besides, afemale and eight male members of the Disaster Management Committee were also invited foranother FGDs in order to understand vulnerability and common emergency response in the postflood situation in the village. Addition to that, KIIs were conducted to purposively selected experts
who involved in the emergency response, such as local NGO, the Cambodian Red Cross, andDistrict Health Center.
Collected data summarized and analyzed based on the five-capital asset pentagon of the
Sustainable Livelihood Framework (SLF) (DFID, 1999). By setting the five-capital pentagon human, social, physical, natural, and financial capital- in the key, the framework clarifying
mechanisms of vulnerability, shocks, and transforming process. The SLF distinctly emphasizes
improving capital assets to reduce vulnerability and enhance disaster resilience (Burton, 2012).
RESULTS AND DISCUSSION
General Information and Conditions
Although the villagers suffer from flood annually, after 2000, severe flood damaged the villagers in
2000, 2001, 2011, and 2013. Especially the Southern part of the village is vulnerable to flood due
to its location along or in paddy field (Fig 2 left). Interviewees shared their experience that waterlevel drastically increase to reach the house floor and occasionally cause water runoff to the housewith the raised-floor style. It causes villagers in flood-prone areas to evacuate to higher road andstay in temporary tent for a while (Fig 2 right).
Villagers have similar flood-induced impacts in the post-flood situation, such as foodinsecurity, health problem, financial shortage, lack of accessibility, and loss of human lives andlivestock. Due to lack of portable water, people reluctantly drink flood water, even though it may
cause diarrhea and other health issues. Children generally suffer from diarrhea and accidentaldrown due to unsafe and high-level water. Many villagers also critically suffer from income
shortage without accessibility to the big lake southern part of the village as well as Steung Sen
River, where people gain profit from morning glory and fish sales.

Fig. 2 Shelter in flood-prone areas along paddy field (left) and higher road to evacuate (right)Ⓒ ISERD

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

Humanitarian Actors and their Roles
The study identified four main key humanitarian actors that provide assistances to the Boeung Leasvillage. These are local government including the Commune Disaster Management Committee,
district health care institution, local NGO, the Cambodian Red Cross.
In cooperation with local NGO, local government of Ou Kantor commune established Disaster
Management Committee that consist from representatives of four villages based on the national
disaster risk reduction (DRR) policy in 2011. The committee consists from five female and 12 malemembers who were nominated based on their status, such as commune chief, village chiefs, senior
villagers, and school director and teachers. The main task of the committee is to identify needs ofthe poor for humanitarian assistance and coordinate with humanitarian agencies and provincial
government. Networking effort successfully receive a project to improve community roads by
Ministry of Rural Development and Asian Development Bank (ADB).
Local authority also collaborates with district health care institution to enhance accessibility ofthe poor to medical services by disseminating “the recognition paper for the poor”, which initiatedby Ministry of Planning and Ministry of Interior. This certificate aims to improve accessibility ofthe poor for social services including exemption of medical services.
On the other hand, local NGO named Help Old Ages and Miserable People Organization(HOM) also closely work with poor communities since 2000. With financial support from
ActionAid and Oxfam, HOM works for food security and livelihood, school education, gender,
natural resource management, DRR, Climate Change Adaptation (CCA), water, sanitation andhygiene (WASH) and sexual harassment. HOM also supported local government to establish thedisaster management committee through workshop on hazard map and action plan development.
Reflecting their limited budget for providing humanitarian assistances, they supported villagers toform a village saving groups for pooling money for emergency use. In addition, HOM also
contributed to the establishment of an early warning information system in cooperation with theInternational Cocoa Organization (ICCO).
The other actor is the Cambodian Red Cross (CRC), which works for community resilience,clean water and shelters, microfinance, security, and community-based health development
program since its establishment on 1994. The organization provided humanitarian assistances formore than 20,000 flood-affected families in Kampong Thom province by 2011. CRC normallyprovides assistances based on the request of local authority and selected CRC volunteers in thevillage. Both relief recipients and assistances are decided by local authority and volunteers basedon specific selection criteria including poverty level and family structure.
Capitals and Vulnerabilities of the Boeung Leas Village
Based on the five-capital or asset pentagon of the SLF, this section summarizes existing capitals
and vulnerabilities of the Boeung Leas village. First, the research revealed that the villagers haveskills and basic knowledge on various topics, such as WASH and disaster risk reduction throughworkshops of humanitarian actors. However, physical capability of villagers, mostly women who
take care both the elderlies and children, are incapable of having different livelihood measures
except production and selling of morning glory, rice, and fishing. Second, the village has
appropriate social capital because there are existing disaster management groups in village andcommune level (Fig 3 left). Not only local authorities and disaster management groups, but also
community residents have network with humanitarian agencies directly and indirectly through local
authorities and CRC volunteers. Third, the village has physical capital including water gaugesystem (Fig 3 right), irrigation canals, radio emergency information system, and some boats as
community’s common property. However, the research also exposed that families does not havetransportation means such as bicycle and boats that people can use in the flooded condition toaccess markets, health facilities and school. These physical capitals are what women eager toreceive as humanitarian assistance because they can continuously use in the flooded condition foraccess health services, income generation, and food purchase. Pao Pisey temple is also one ofphysical capital because displaced people are allowed to stay at their 5 buildings and use 4 toiletⒸ ISERD

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

facilities until flood water drain. The temple also provides stock of foods such as rice and canned
fish to displaced people. Fourth, natural capital of the Boeung Leas village is limited because thevillage regularly suffer from flood and have challenges on acquiring safe drinking water and foodresources. Besides, most of interviewees of the study stated that they have limited sources forlivelihood (rice production and naturally grown morning glory harvesting as well as fishery) due totheir educational background. Although the village has paddy fields, these are owned by the richand not allocated for the vulnerable families to harvest agricultural crops. Fifth, financial capital ofthe village and household level is limited because local authority does not have enough finance toprovide facilities that requested by dwellers, such as community toilet and boats. That is why
residents collects savings and request provincial government to provide toilets. When we consider
about individual level, the most vulnerable families who live along or in the paddy field mentionedthat financial shortage is the key factor why they continuously stay in the flood-prone areas. They
do not have money to move, do not know where to move, and do not know what to do forlivelihood in other areas.

Fig. 3 FGDs with Disaster Management Committee (left) and water gauge system (right)
According to Kafle (2017), South Asian countries have following seven major vulnerability
factors; (1) high population density, (2) weak governance, (3) climate change, (4) high rate ofurbanization, (5) ineffective DRR structure, (6) poverty due to high unemployment of women andyouth, and (7) population increase and natural resource degradation. The research also identified
some of these causes in the Boeung Leas village. For example, majority of households in thevillage face poverty and most of male adults migrate to other cities/ countries for earning moreincome. Due to limited amount and frequency of remittance, adult female responsible to earn
income and take care family members simultaneously. Although people recognize vulnerability of
the living area, they helplessly stay in the same area due to their financial shortage. People also
specified that they cannot prepare anything without financial surplus, even though they receive
lectures on disaster preparedness. For the community level, local authorities and village leader also
suffer from financial shortage and does not have adequate amount of budget to invest for disasterrisk reduction. Therefore, commune strongly depend on financial support of National DisasterCommittee. Another example is weak governance and ineffective local DRR structure.
Inappropriate decision-making of commune council chief and paddy field owners deteriorate theflood situation because they delay water release from paddy field. Although residents suffer fromhigh-level water and water runoff in their houses, the commune council chief does not releasewater until receiving request from landowners because flood water make paddy field fertile. It wasalso revealed that early warning information dissemination of the disaster management group isinadequate, and people obtain information more from television and radio, and direct information
sharing in the local authority. Besides, most of decision-making on recipient selection andassistance components were decided by local authorities and specific volunteers without needs
assessment and any participation of the vulnerable households. It accumulated frustration anddoubt about corruption of local authorities to injustice selection of receivers.
Ⓒ ISERD

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

Gaps between Humanitarian Assistance and Needs
The study identified four main gaps between humanitarian assistance and needs of vulnerable
women to decrease vulnerability in Boeung Leas village.
First gap was inconsistent humanitarian assistance with prior needs of people. Women eager
to receive long-term aids, such as boat, bicycle, fishing net and other materials that people canutilize for income generation and enhance their accessibility to facilities including school, hospital,
market. However, focus of humanitarian actors in post-flood situation is prevention of hunger for
few days, and that is why they normally distribute short-term aids, such as 25 kilogram of rice,canned fish, noodle, fish sauce. Sometimes they also distribute blue tarpaulin to reinforce damaged
roof. This inconsistency of aids happens due to lack of needs assessment before decision-making
on humanitarian assistance consist of financial and human resource shortage of humanitarian actors,
even though De la Torre et al. (2012) stated that accurate needs assessment is crucial for achieving
maximizing the benefit of distributing relief goods.
Second gap was distribution approach. Villagers expects equal distribution of humanitarianassistance among flood-affected households immediately after the occurrence of flood. But it isdifficult for humanitarian actors because of financial and human resource shortage. Unequal
distribution generally caused jealousness and doubt for local authority among villagers who could
not receive humanitarian assistance.
Third gap was different priority among commune council chief, paddy field owners, andflood-affected people. It is clear from the findings that prolonged water release of paddy field that
affect houses was decided by commune council chief in order to fertile paddy soil. In other words,
the local authority set their priority to benefits the rich rather than the safety of the flood-affectedfamilies. In addition, villagers hesitate to claim commune council chief directly because they afraid
criticism of local authority and the rich.
The last gap was ineffective recognition of the poor with “the recognition paper for the poor”.
The purpose of this paper is to improve accessibility of the poor for medical and other social
services. However, some medical facilities reject the poor to exempt their payment, or sometimes
request recommendation letter from community leaders. Ineffective recognition of the poor andlimited financial resources for transportation keep people away from medical services.
CONCLUSION
According to the results and discussion done in this study, it is identified that Boeung Leas village
is vulnerable to flood and annually suffer from flood-induced issues, such as food insecurity andhealth problem. The village has adequate human and social capitals specifically knowledge on
DRR, network, the disaster management group in the village or the commune. By contrast, both thevillage and individual households have space for improvement on physical, natural, and financial
capitals because these shortages induce food insecurity, limited accessibility and income generationin post-flood situation. Besides, the village has common vulnerability causes similar to other South
Asian countries, specifically on poverty, weak governance, and insufficient local structure on
disaster risk reduction.
The study also identified main gaps between humanitarian assistance and needs of vulnerable
women to decrease vulnerability in Boeung Leas village. First, there are inconsistent humanitarian
aids with prior needs of people due to lack of needs assessment and dependency on limited local
authority and villagers. Second, financial and human resource shortages of humanitarian actors
limit equal distribution of assistances to flood-affected people, even though villagers expect equal
distribution among them. Unequal distribution and limited humanitarian assistance distribution
created jealousness and doubt of villagers on local authority. Third, there are gap between priority
of commune management chief, paddy field owners, and vulnerable women. Although they could
help flood-affected households by release water from paddy field, authorities prioritize benefit for
paddy owners to fertile paddy soil. The study also identified the cases that ineffective recognitionⒸ ISERD

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2of the poor and limited financial resources for transportation keep people away from medical
services.
For improving resilience of the Boeung Leas village for future flood, attention should be paid
for Build Back Better, which is the process to improve community’s resilience and capacity, while
reducing their vulnerability simultaneously. Specifically, the study recommends humanitarian
actors to focus not only on short-term assistances for few days, but also enhancement of local
governance and local systems on disaster risk reduction including participatory decision-making
system for pre- and post-flood affected condition. It is because that reflection of past experienceand challenges contributes to create evidence-based disaster risk reduction and management
structures in the village. Poverty reduction through creating alternative livelihood options is also
vital components to improve community resilience.
ACKNOWLEDGEMENTS
Authors would like to express appreciation to stakeholders in Steung Sen district, as well as
professors and colleagues in University for Peace (UPEACE) and Ateneo de Manila University,
especially Prof. Diana J. Mendoza who supervised the study. Our gratitude also goes to Nippon
Foundation that tirelessly supported our study under the Asian Peacebuilders Scholarship (APS)
program. This study was developed based on the graduation research project under APS program.
REFERENCES
Burton, C.G. 2012. The development of metrics for community resilience to natural disasters. Ph.D. thesis.
University of South Carolina, USA.
Cannon, T., Twigg, J. and Rowell, J. n.a. Social vulnerability, sustainable livelihoods and disasters.
De la Torre, L.E., Dolinskaya, I.S. and Smilowitz, K.R. 2012. Disaster relief routing: Integrating research andpractice. Socio-Economic Planning Sciences, 46, 88-97.
Development Initiatives. Defining humanitarian assistance. Retrieved from http://devinit.org/defininghumanitarian-assistance/
Dworkin, S.L. 2012. Sample size policy for qualitative studies using in-depth interviews. Archives of Sexual
Behavior, 41, 1319-1320.
Humanitarian Policy Group. 2006. Humanitarian response to natural disasters.
International Federation of Red Cross and Red Crescent Societies. n.a. Disaster preparedness. Kafle, S. 2017.
Disaster Risk Management Systems in South Asia: Natural Hazards, Vulnerability, Disaster Risk andLegislative and Institutional Frameworks.
Mannakkara, S. and Wilkinson, S. 2015. Build back better principles for reconstruction.
Schilderman, T. 2010. Putting people at the centre of reconstruction (Chapter 1). Lyons, M. et al (eds.).
Building Back Better.
The British Department for International Development. 1999. Sustainable livelihoods guidance sheets.
Retrieved from http://www.ennonline.net/dfidsustainableliving
United Nations Development Programme. 2012. Livelihood recovery needs assessment and action plan for
selected area affected by the 2011 Cambodia flood. UNDP.
Wisner, B., Blaikie, P., Cannon, T. and Davis, I. 2004. At risk: natural hazards, people’s vulnerability anddisasters. Routledge, USA.

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Research article
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Properties of Lightweight Concrete Using Expanded
Polystyrene as Aggregate
EIJI MATSUO*
Faculty of Architecture and Civil Engineering, Kyushu Sangyo University, Fukuoka, Japan
Email: ematsuo@ip.kyusan-u.ac.jp
Received 7 December 2018

Accepted 10 July 2019(*Corresponding Author)

Abstract When large structures are built on the soft ground such as paddy field, thedemand for lightweight concrete will be high. However, issues related to quality control oflightweight aggregates, decline in the tensile strength of lightweight concrete, the economic
problems, and so on, have been inhibiting the promotion of its development. There aresome conventional methods of construction to cast the large size of expanded polystyrene(EPS) blocks near the surface of soft ground. But there is concern that the EPS block will
float up by liquefaction in case of earthquake. In this study, the strength properties oflightweight concrete which uses EPS waste as fine aggregate have been investigated. The
above-mentioned concern could be wiped out by mixing EPS as aggregate in concrete
aggregate. This EPS aggregate is manufactured product, but there is extremely little numberof the factories. The volume of this aggregate was reduced by being irradiated the extreme
infrared radiation to utilize the stockyards effectively. This aggregate is ecological because
its origin is the industrial waste of EPS. That the absorption of water is zero is one of themerits as the aggregate for concrete. The author has obtained experimentally the mix
proportions for the concrete that have the compressive strength enough to be used as
structural material. As the results, the treatment of EPS using extreme infrared radiation
was found to be effective in improving the strength of EPS concrete.
Keywords lightweight concrete, expanded polystyrene, strength, density

INTRODUCTION
In Japan, the annual discharge of industrial waste is over 400 million tons which is about 8 times
that of general wastes (Japan Environmental Sanitation Center, 2000). About 80 million tons ofthem are discharged from the construction industry. After the recycling law was enforced,
development of technologies for effective use of the waste has been much desired.
The main objective of this study is the successful utilization of expanded polystyrene waste(EPS for short) as fine aggregate to produce lightweight structural concrete. The quantity of EPS
production in Japan is about 200,000 tons, which accounts for about 10% of the total global
production. Only 64% of them have been recycled, the rest being incinerated or reclaimed. Various
technologies have been developed for the reduction of EPS volume. Although structurallightweight concrete can be produced using artificial lightweight aggregates, the major drawback is
the high cost of these aggregates. Using EPS as aggregate makes the production of lightweight
concrete economical and environmentally friendly. In addition to the lightweight property, EPS hasother beneficial properties such as high thermal insulation, high sound absorption, and super low
water absorption.
There are extremely few studies on EPS concrete except the case study as non-structurematerial (Nagase et al., 2000). There are some studies on structural lightweight concrete whichwere confirming the basic properties and trying a multifunctionality, however the artificial
aggregate is expensive (Kuku et al., 2000), (Onishi et al., 2000). Then the originality of this study
is to use this EPS for structural concrete, and the objective of this paper is to quantify the basic
properties of density and strength.

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METHODOLOGYa) Property of EPS Aggregate
Fig.1 shows the EPS used in this study and a section of an EPS concrete cylinder. Table 1 gives
various physical properties of EPS aggregate. Methods of reducing the volume of EPS waste are
extreme infrared ray irradiation processing, a new technology, has been performed on this EPS. In
this method, firstly the EPS is roughly crushed, and inorganic powders are sprinkled on its surface
using small amount of resin adhesive. Then, the volume is reduced to about 1/20 by irradiation of
extreme infrared rays before being ground again into fine pieces. With this processing, the strengthand the Young's modulus accompanying the increase of density is more than that of theconventional EPS. Because the processing is done in a low temperature of 120-130 degrees-C,
generation of unpleasant odour is limited. Loss percentage of mass was 0.55% as shown by thestability examination (Test method for soundness of aggregates using sodium sulphate, JIS A
1122). The resistivity against aging deterioration was confirmed to be as high as that of aggregatesfor normal concrete.
In the case of conventional lightweight concretes, the limit of weight reduction has been about
1.5t/m3. ALC (Autoclaved Lightweight Concrete) has been put into practical use to advance further
weight reduction. In this case, if water from rain etc. is absorbed into air spaces, the density will
increase greatly. There is little study on using EPS as aggregate for concrete (Matsuo et al., 1994,
1995, 1996, 1997).
b) Experimental Details
The key points in using a lightweight material like EPS are suppression of segregation, evaluationof fresh condition, and to control the decrease of strength. In the experiments, the relation between
the density and the strength of specimens accompanying the change in the quantity of EPS andwater cement ratio (W/C) was investigated first. The mix proportions were selected based on the
result anticipating a compressive strength of 30N/mm2 in the super lightweight domain.
Segregation must be prevented in order to stabilize the strength. For this, adequate mix proportionsof EPS concrete that could control the segregation and have good workability were established byobtaining the relationship between the segregation and viscosity of the cement paste prior to thestrength tests.

50mm

W/C=40%，V=50%
W/C=40%，VEPS
EPS=50%

Fig.1 EPS and the section of an EPS concrete cylinder
Table 1 Properties of EPS
Density (g/cm3)
Maximum size of sieve (mm)Percentage of solid volume (%)
Fineness modulus
Water absorptivity (%)
Quantity loss of aggregate (%)Ⓒ ISERD

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0.53
4.0
64.8
3.02
0
0.55

IJERD – International Journal of Environmental and Rural Development (2019) 10-2

Strength properties and the density of EPS concrete were investigated and compared with paststudies (Matsuo et al., 1994, 1995, 1996, 1997). Mix proportions that can control segregation wereselected based on the results mentioned previously. The variation in the strength of EPS concrete
was also examined. Admixtures were not used so that the most fundamental properties could be
investigated. Additionally, the effect of a super plasticizer was also confirmed. It was also
confirmed from preliminary experiments that segregation could be controlled even without the
thickening agent (thickner, or viscosity increasing agent).
c) Mix Proportion and Casting Method
The material used here is the same as the one mentioned previously. The representative mix
proportions are shown in Table 2 which can control segregation and have a small density difference.
VEPS means the volume ratio of EPS in concrete. Mixing was done using a mortar mixer/force
mixer. Experiments were carried out using EPS concrete prisms (4×4×16cm) and cylinders(φ10×20cm). The prisms were compacted 40 times in two layers, and the cylinders werecompacted 25 times in 3 layers. A table vibrator was used as required. Specimens were removed
from the molds one day after casting and they were cured in water until the strength test.
Table 2 Representative Mix Proportions

W/C VEPS Unite Weight (kg/m3)

Name(%) (%)
30 40
40 50

A
B

C
972
697

W
292
279

TheoreticalEPS Density (g/cm3)
212
1.48
265
1.24

RESULTS AND DISCUSSIONa) Relation between VEPS and Strength
An instance of density change of EPS concrete with the increase of VEPS is shown in Fig. 2. The
density decreases linearly as VEPS increases. Since the difference of theoretical density and actual
density is very small in all mix proportions, it can be inferred that EPS waste had not been
compressed with cement paste during the mixing and hardening.
Fig. 3 shows the relationship between VEPS and the compressive strength. The compressive
strength decreased with the increase of VEPS. Even if VEPS is about 50%, a compressive strength of
15-30N/mm2 can be obtained with small water cement ratio. The fact that a compressive strength of
19-45N/mm2 can be obtained for VEPS as small as 20-30% suggests that EPS concrete can bebroadly used as structural materials as well as non-structure materials.
W/C=30% Actual
W/C=35% Actual
W/C=50% Actual
W/C=60% Actual

Concrete Density (g/cm3)

2.2
2.0

W/C=30% Theoretical
W/C=35% Theoretical
W/C=50% Theoretical
W/C=60% Theoretical

1.8
1.6
1.4
1.2

1.0
0

10

20

30
VEPS (%)

40

50

60

Fig. 2 Relationship between VEPS and concrete densityⒸ ISERD

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Compressive Strength by Cubic (N/mm2)

IJERD – International Journal of Environmental and Rural Development (2019) 10-2

W/C=30%
W/C=35%
W/C=50%
W/C=60%

70
60
50
40
30
20
10
0
0

10

20

30
VEPS (%)

40

50

60

Fig. 3 Relationship between VEPS and compressive strengthb) Density and Strength
Fig. 4 shows the relationship between concrete density and compressive strength for cubic EPS
concrete specimens. The results for every VEPS and compared with a previous study (Matsuo et al.,1994). For given concrete density, the strength of EPS concrete is larger than that of the previous
beads-type EPS for all VEPS. This reflects the effectiveness of the volume reduction method using
extreme infrared ray to EPS is relatively more effective regarding the strength. Furthermore, it isalso estimated that the increase in the strength can be attributed to the increase of adhesion strength
between the paste and EPS due to the complexity of the surface shape of EPS.

2

Compressive Strength (N/mm )60
50Thin Lines : Past Study
Thick Lines : This Study(without Agent)Line with Mark : This Study(with Agent)

40
30
20
10
0
0.8

1.0

1.2

1.4

1.6

1.8

2.0

2.2

3

Density (g/cm )Fig. 4 Relationship between concrete density and compressive strength
Bache’s equation was used in order to determine the mix proportion which can utilize thestrength of EPS more effectively (Bache, 1967). Bache expressed the strength of concrete as Eq.
(1) in case that the strength of aggregates is weaker than the matrix. This is empirical and has thegeneral tendency to underestimate the strength of the aggregate to be calculated. The effective
mixing ratio of the aggregate is said to be in the range of 0-0.5. There are various views regarding
the effective range concerning the strength ratio of the aggregate and the matrix (Murata et al.,1968).

𝜎𝑐 = 𝜎𝐸𝑃𝑆 𝑉𝐸𝑃𝑆 ⋅ 𝜎𝑝 1−𝑉𝐸𝑃𝑆(1)Ⓒ ISERD

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Here,  is the compressive strength (N/mm2), c means concrete and p means paste.
Eq. (1) can be expressed as

𝜎𝐸𝑃𝑆 = 𝑒𝑥𝑝 {log 𝜎𝑐 −(1−𝑉𝐸𝑃𝑆 ) log 𝜎𝑝
𝑉𝐸𝑃𝑆

}

(2)

Estimaed Compressive Strengthof EPS (N/mm2)

Substituting the result of Fig. 3 in Eq. (2) the compressive strength of EPS for all mix
proportions can be found. In practice, since the strength of EPS is constant, the authors think that
this calculation value is the resistance which EPS shares with the cement paste matrix to the acting
compressive stress. Here, it is called “estimated strength”. Change of estimated strength of EPS
with VEPS is shown in Fig. 5 for different water cement ratio of paste. The estimated strength of
EPS changes not only with the paste matrix strength but also with VEPS. Mix proportions with VEPS
about 40-50% and high paste strength can use the EPS strength advantageously. These mix
proportions are closely in agreement to the ones which control segregation discussed previously.
Stress-strain curves for various VEPS are shown in Fig. 6 with 35% of water cement ratio. The
elastic modulus obtained from this figure is shown in Fig. 7. It is observed that the elastic modulus
decreases linearly with VEPS, a trend similar to that shown by the compressive strength.
3.5

3.0
2.5
2.0

1.5

W/C=30%
W/C=35%
W/C=50%
W/C=60%

1.0
0.5

0.0
10

20

30

40
VEPS (%)

50

60

70

Fig. 5 Estimated compressive strength of EPS

50

W/C=35%Stress (N/mm2)

40
30
20

EPS20%EPS30%EPS40%EPS50%

10
0
0

1000

2000

3000
Strain (μ)

Fig. 6 Stress-strain curvesⒸ ISERD

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4000

5000

IJERD – International Journal of Environmental and Rural Development (2019) 10-2

Elastic Modulus (kN/mm2)

16
14
12
10
8
6
20

25

30

35

40

45

50

VEPS (%)

Fig. 7 Relationship between VEPS and elastic modulus
CONCLUSION
In this study, fundamental strength properties of lightweight concrete using EPS as fine aggregate
were investigated. The main conclusions are as follows.
(1) Irradiation of EPS by extreme infrared rays is effective in improving the strength of EPS
concrete.
(2) The mix proportions which authors propose are "W/C=40% and V EPS=50%" for weight
reduction, and "W/C=30% and VEPS=40%" for high strength.
Drying shrinkage is the subject for a further study in case of the applicability of this concrete
in a large scale. It is necessary to quantify the adequate amount of shrinkage reducing agent.
REFERENCES
Bache, H.H. 1967. Testing and design methods of lightweight aggregate concretes. Proceedings of RILEM
International Symposium, Budapest.
Japan Environmental Sanitation Center. 2000. Waste management and recycling in Japan, 18.
Kuku, M., Suzuki, T. and Sakaguchi, N. 2000. Artificial super lightweight aggregate structural concrete.
Proceedings of JCI Symposium on High Performance Structural Lightweight Concrete, Japan Concrete
Institute, 5-10.
Matsuo, E., Makizumi, T. and Sakamoto, Y. 1995. Control of segregation of polystyrene beads concrete. JCA
Proceedings of Cement & Concrete, 49, 826-831.
Matsuo, E., Matsushita, H. and Makizumi, T. 1996. Study on mix proportion of super lightweight concrete.
JCA Proceedings of Cement & Concrete, 50, 364-369.
Matsuo, E., Matsushita, H. and Makizumi, T. 1997. Property of super lightweight concrete using expanded
polystyrene beads as coarse aggregate. JSCE, Journal of Materials, Concrete Structures and Pavements,
571, 36, 37-48.
Matsuo, E., Sakamoto, Y. and Makizumi, T. 1994. Effect of the chopped fiber reinforcement on thepolystyrene-bead concrete. JCA Proceedings of Cement & Concrete, 48, 774-779.
Murata, J. and Kamiyama, Y. 1968. Study on the testing method for strength of aggregate. Japan Cement
Association, Annual Report of Cement Technology, 22, 223-225.
Nagase, K., Tanaka, H., Jinnai, H., Ookida, K., Yamada, T. and Goto, K. 2000. Use of lightweight andthermally insulating exterior wall concrete panels containing EPS waste as aggregate. Proceedings of JCI
Symposium on High Performance Structural Lightweight Concrete, Japan Concrete Institute, 159-164.
Onishi, T., Toda, Y., Takemura, G. and Nakamizu, T. 2000. Fundamental properties of concrete using
lightweight fly-ash aggregate. Proceedings of JCI Symposium on High Performance Structural
Lightweight Concrete, Japan Concrete Institute, 23-28.

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Research article
erd

An Assessment of Soil Chemical Properties and Yields ofBlack Gram, Using GIS, in a Selected Area of Myanmar
HTAY HTAY OO*
Yezin Agricultural University, Myanmar
Email: htay.agro96@gmail.com

KHIN MAR OO
Yezin Agricultural University, Myanmar

SWE SWE MAR
Yezin Agricultural University, Myanmar

NAING NAING MOE
Yezin Agricultural University, Myanmar
Received 14 December 2018

Accepted 10 July 2019(*Corresponding Author)

Abstract In Myanmar, pulses are a very important crop with great potential for export.
Black gram (Vigna mungo L.) is one of the predominant pulse species grown, with planting
after the harvest of monsoon rice in the winter season. Understanding the spatial variabilityof soil chemical properties is critical for improving the productivity of pulses and ensuring
sustainable farming practices. However, a systematic assessment on the spatial variabilityof pulses yield has not been conducted. Therefore, this study was carried out to examine
the variability of black gram yields in relation to soil chemical properties, at Kyee Inn
Village, Pyinmana Township, central Myanmar from May 2017 to March 2018. Eighty
composited soil samples were collected across the study area and analyzed for common
soil chemical properties. Sixty seven farmers were surveyed as sample respondents todetermine yields and management practices. Interpolation allowing overlay mapping ofvariations in black gram yields on soil chemical properties was accomplished using ArcGIS
software. It was observed that these soil chemical properties and black gram yield varied
considerably throughout the study area. Slight variability was observed in total nitrogencontent. The pH value of the soils was moderately acidic to moderately alkaline with pH
values of 5.48 to 7.58. The fields were characterized by low levels of soil organic matterand total phosphorus. The variation in black gram yields, ranging from 0.16 to 1.97 ton perhectare, is probably a result of the high variation of total soil nitrogen and phosphorus
content. The results suggest that to improve soil fertility and sustain and improve black
gram yields, it is very important to apply organic matter, nitrogen and phosphorus in partsof the study area.
Keywords black gram, GIS, overlay mapping, organic matter, total nitrogen andphosphorus, yield, sustainable farming

INTRODUCTIONIn Myanmar, pulses are an important crop with great potential for export, and the rapid growth inproduction has been driven by a huge demand from India. Black gram (Vigna mungo L.) is one of
the most favored species farmed in Myanmar, in terms of acreage and production output. Pulses areimportant for crop intensification, diversification and conservation of natural resources as well as
the sustainability of farm production systems, because of their short growth duration, dense crop
canopy and versatility (Katiyar and Dixit, 2010). However, black gram is generally produced infields that have a high degree of variability in soil type, topography, soil moisture and other major
factors that can affect crop yield.
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GPS based soil fertility maps have been prepared by a number of different government andprivate sector organisations for different areas of Myanmar. Remote sensing (RS), geographicalinformation systems (GISs) and geo-statistics are tools becoming progressively more central tofields of research like agriculture (Bocchi et al., 2000; Basso et al., 2001). Scientific information
relating spatial variability to distribution of soil properties is critical for farmers attempting toincrease effectiveness of fertilizer use and maximize crop productivity. Fertilization of a crop basedon specific parameters of soil fertility, should also result in minimalizing fertilizer inputs without
reducing yield (Jalali, 2007). Geo-statistics have been used to analyse the spatial variability of soil
properties and crop yield (Stevenson et al., 2001). However, a systematic assessment on the spatial
distribution and variability of pulse yields and soil chemical properties has not been conducted in
Myanmar. Evaluating the spatial variability of pulse yields in relation to the chemical properties ofsoils allows micro-adjustments that are essential for regional planning purposes, promoting
sustainable pulse production and increasing levels of productivity.
OBJECTIVES
The present study was carried out to examine the current status and spatial variability of soil
chemical properties and the relationship of this to black gram yield. Maps of the study area weregenerated to illustrate this relationship.
METHODOLOGY
Study Site and Data Collection
The research was carried out in central Myanmar. The study site is Kyee Inn Village, Pyinmana
Township, which lies between 1970'66'' - 1972'62'' N and 9622'43'' - 9625'73'' E and examineda total study area of 486 ha, from May 2017 to March 2018 (Fig. 1). Farmers in the study area
usually practice what can be described as a monsoon rice-pulse cropping pattern. The mean annual
rainfall is approximately 1420 mm and daily mean temperature, 26.8°C. The study area wassuperimposed with 300 m × 300 m geographic grids using geographical information system (GIS)
tools, and comprised 80 sample grid points (Fig. 2). Among these 80, only those grids where
farmers had cultivated black gram were included in the survey. Accordingly, 67 farmers wereselected as sample respondents and information about average yield per acre and crop management
practices was collected through interview and structured questionnaire. For soil analysis, each grid
had three soil samples taken, these at a depth of 0-15 cm. The 3 samples from each grid werecombined to give a composite sample. To avoid undesirable effects due to fertilization in thegrowing period, samples were taken after harvest.
Sensors were on a DJI Phantom 4 drone and Litchi software was used to interpret information.
Flight altitude was 120 meters and the drone images were combined and processed using pix 4D
software for digitizing and relating these to the digital base map of the study area. ArcGIS softwarefrom Environmental Systems Research Institute (ESRI) was used to produce maps of the spatial
distribution of yield and soil chemical properties. Interpolation and overlay mapping weregenerated using Inverse Distance Weighting (IDW) and the Radial Basis Function (RBF) which
are deterministic interpolation methods in the Arc GIS 10.5 software according to Meng et al.
(2013).
Statistical Analysis
All relevant data were subjected to analysis using the Statistix 8 program. Mean, standard deviation,and standard errors were determined for each of the soil properties considered as well as soil
moisture content and yield of black gram, using descriptive statistics. The variability of each
property was measured by coefficient of variation (CV) expressed as a percentage.
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Laboratory Analysis
Laboratory analysis was conducted for the composite soil samples. This involved air-drying,pounding, and sieving (2.0 mm sieve) and storage at 4°C in a cool room. Soil pH was measured
using a digital pH meter in soil to water solutions, consisting of a 1:5 suspension, after 30 minutesof mixing (Hesse, 1971). Total soil nitrogen was determined using the Kjeldahl digestion,
distillation and titration method (Bremmer, 1982) whereas total soil phosphorus was analyzed
using spectrophotometer measurement of blue molybdatephosphate complexes under partial
reduction with ascorbic acid (Jackson, 1958). Soil organic matter was determined using the wet
digestion method (Walkley, 1934).
Pyinmana TownshipFig. 1 Location of the study area

Fig. 2 Grid sampling points

RESULTS AND DISCUSSION
Spatial Variation in Soil Chemical Properties
The coefficients of variation (CV) were grouped into three categories; these being, least variable(<15%), moderately variable (15-35%) and extremely variable (>35%). That is, the higher the CV
the more variable the soil property measured. Data were subjected to analysis by descriptive
statistics to determine significant differences between the black gram yield, soil moisture content(MC) and soil chemical properties. A large variation in soil chemical properties was observed
across the study area. In terms of variation in soil properties, total nitrogen shows the highest
variability with a CV of 68.52%, followed by soil organic matter with a CV value of 34.56%,
whereas variations for soil pH and total phosphorus show least variability with CVs of 5.13% and6.25% respectively (Table 1). The results indicate that there is natural variation, which is often
compounded by nutrient management practices used by farmers. This has implications for black
gram production since soil chemical and soil water content variability can be expected to lead tovariability in crop yield.
Soil pH
Table 1 Descriptive statistics of yield, soil water content and soil chemical properties
Variables

Unit

Minimum

Maximum

Mean

SE

SD

CV%

Estimated Yield

ton ha-1

0.160

1.970

0.840

0.043

0.364

43.348pH-log [H+]
%

5.480

7.580

6.244

0.038

0.320

5.127

1.790

9.640

4.928

0.182

1.545

31.358Organic Matter

%

0.200

1.700

0.893

0.036

0.309

34.562

Total Nitrogen

%

0.010

0.330

0.114

0.008

0.078

68.520Total Phosphorus

%

0.017

0.024

0.019

0.001

0.001

6.249

Soil Water

SE: Standard error; SD: Standard deviation; CV: Coefficient of variationⒸ ISERD

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

The soil pH of the study area was found to be acidic to slightly alkaline and ranged from 5.48 to7.58 (Table 1). Black gram prefers soil with a pH in the range 5.5 - 6.5, tolerating 4.5 - 7.5 (Katiyar
and Dixit, 2010). Thus, the variability of soil pH may be assumed to not represent a major
contributing factor to variation in black gram yield.
Soil Organic Matter and Soil Water
The estimated average yield for black gram in the study area was obtained through surveying
farmers, by both interview and structured questionnaire. From the sample plots, black gram yields
range from 0.16 to 1.97 ton ha-1 (Table 1). These data were overlain on to maps of soil organic
matter and soil moisture for the study area (Fig. 3a and 3b).
The black gram cultivars commonly used in Kyee Inn Village, Pyinmana Township are Yezin-2,
Yezin-5 and Yezin-6 (Fig. 2). In general, yield exhibited the following characteristics. The grid points
in the eastern part of the study area produced higher yields, ranging from 0.99 to 1.48 ton ha-1.
Moreover, the sample grid points where the black gram cultivars were Yezin-2 and Yezin-6 hadhigher yields than area where Yezin-5 was planted. According to the Department of Agricultural
Research (DAR), the potential yield of Yezin-5 (1.6 - 2.0 ton ha-1) is lower than that of Yezin-2 (2 2.4 ton ha-1) and Yezin-6 (2.4 - 3.2 ton ha-1) when grown under same conditions. Thus, the study
affirms that Yezin-2 and Yezin-6 should be grown instead of Yezin-5 in upcoming seasons toincrease productivity.
Soil organic matter and soil water have very important functions that correlate positively tonutrient availability and retention. It should also be taken into consideration that the nutrient input
from soil contributes considerably to crop nutrition (Fu et al., 2010). The amount of soil organic
matter is highly dependent on a range of ecological factors such as climate, soil type, vegetative
growth, topography in which it occurs as well as land use and management and tillage of the soil
and intensive cropping (Rawal et al., 2018). The spatial distribution of organic matter and soil
moisture (in percent) exhibits a gradual percentage increase from the northeast portion to thesouthwest portion of the study area, where the highest content for both are found. One possible
reason for this is the slightly higher elevation of the northern portion with accumulation of organic
matter and moisture often favored at lower levels. The average soil organic matter content of study
area varies from 0.2 to1.7% with a mean value of 0.893%, which is very low when soil organic
matter greater than 2.6% is considered to provide good nutrient storage (Purdie, 1998). In theoverlay mapping, all sampling grid plots had insufficient levels of soil organic matter and there ishigh variation in percentage content. This suggests the low yields for black gram, and spatial
variability of these yields may be attributed to the poor crop management practices, with a failure
to systematically apply organic and inorganic fertilizers.

Fig. 3 Overlay mapping of distribution of yield and cultivars for (a) soil water content and (b)soil organic matter in Kyee Inn Village, Pyinmana Township, 0.98: mean yield of black
gram in ton ha-1
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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

Total Nitrogen and Total Phosphorus
Soil fertility is one of the major constraints to agricultural production in tropical countries,
including Myanmar. Examining the current soil fertility status is important because it could provide
valuable information relating to crop research (Khadka et al., 2017). Soil nitrogen is one of themost important plant nutrients, and of all nutrients, the most frequently deficient (Havlin et al.,2010). The total nitrogen content varies from 0.01% to 0.33% with the mean value of 0.114% inthis study (Fig. 4a). The critical value of total N in soil is 0.12% (Shah et al., 2008). The overlay
mapping, show most of the sampling grid plots have low levels of total nitrogen. This low nitrogencontent may relate back to the insufficient level of soil organic matter content in the study area.
The percentage value of total phosphorus ranges from 0.017 to 0.024% with a mean value of0.019%. In most soils, P content is very low in the surface layer and represents less than 1% of total
P. However the total P content of a soil may vary widely and depend on factors such as organic
matter content, climatic conditions, parent materials and application of fertilizers (Mansour et al.,2014). In the overlay mapping, about half of the sampling area is medium in range, whereas the restof the study area is in a lower range for phosphorus content (Fig. 4b).
The yield variations in black gram already mentioned also may be related to the variations insoil nitrogen and phosphorus content. Low levels of phosphorus can be ameliorated by replenishingwith fertilizers which contain high amounts of available phosphorus. In the overlay mapping of Fig.
4.a and Fig. 4.b, it can be seen that most sampling grid plots not only have low levels of soil
nutrients but are sown with different black gram cultivars. Therefore, results suggest the spatial
variability of black gram yield can be attributed to the poor crop management practices, such as theinsufficient application of nitrogen and phosphorus fertilizers, in combination with the selection ofpoor yielding cultivars for planting.
(a)

(b)

Fig. 4 Overlay mapping on distribution of yield and cultivars on to (a) total nitrogen and (b)total phosphorus in Kyee Inn Village, Pyinmana Township, 0.98: mean yield of black
gram in ton ha-1
CONCLUSION
Results clearly show that most of the area under black gram cultivation has low levels of organic
matter, with total soil nitrogen and phosphorus also below desired levels. Due to continuous tillage
and the failure to add organic matter, and with minimal nutrient supply from either natural or
artificial sources, low levels of these nutrients pertain in the study site. The pH range of soils in the
study area should not present a problem for the black gram cultivation, and cannot be assumed as amajor factor contributing to the spatial variation in yields of black gram. The results suggest that toimprove soil fertility and sustain black gram production, it is very important to apply organic
matter and phosphorus, particularly in certain parts of the study area. The overlay maps provide aⒸ ISERD

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

readymade source of information about the status soil fertility and can serve as a spatially accurate
decision making tool for successful black gram cultivation. It can be concluded from the present
study that GIS based soil fertility maps help farmers by providing spatially specificrecommendations regarding fertilizer application, improving crop production and ensuring greater
sustainability.
ACKNOWLEDGEMENTS
We would like to acknowledge the Japan International Cooperation Agency for TechnicalCooperation Project (JICA-TCP) at Yezin Agricultural University for providing financial andtechnical support. We wish to extend sincere gratitude to Pro-Rector Dr. Kyaw Kyaw Win, and Dr.
Kazuo Watanabe for their generous technical support and valuable advice in this study. Our
appreciation is also extended to the authorized staff at the Department of Agriculture (DoA) and
Department of Agricultural Land Management and Statistics (DoALMS) for data provision.
REFERENCES
Basso, B., Ritchie, J.T., Pierce, F.J., Braga, R.P. and Jones, J.W. 2001. Spatial validation of crop models for
precision agriculture. Agric. Syst., 68, 97-112.
Bocchi, S., Castrignano, A., Fornaro, F. and Maggiore, T. 2000. Application of factorial kriging for mapping
soil variation at field scale. Eur. J. Agron., 13, 295-308.
Bremmer, J.M. and Mulvaney, C.S. 1982. Nitrogen-total. In: Page, A.L., Miller, R.H. and Keeney, D.R.
(Eds.), Methods of Soil Analysis, Part 2-Chemical and Microbiological Properties, ASA-SSSA, Madison,
WI. 595-624.
Fu, W.J., Tunney, H. and Zhang C.S. 2010. Spatial variation of soil nutrients in a dairy farm and its
implications for site-specific fertilizer application. Soil Tillage Res., 106, 185-193.
Havlin, H.L., Beaton, J.D., Tisdale, S. L. and Nelson, W.L. 2010. Soil fertility and fertilizers, An introduction
to nutrient management. 7th Edition, PHI Learning Private Limited, New Delhi, India. 516.
Hesse P.R. 1971. A text book of soil chemical analysis. John Murray, London.
Jalali, M. 2007. Spatial variability in potassium release among calcareous soils of western Iran. Geoderma,
140, 42-51.
Jackson, M.L. 1958. Soil chemical analysis. Prentice-Hall. Engle-wood Cliffs, N.J. 498.
Katiyar, P.K. and Dixit, G.P. 2010. Genetic divergence in Indian black gram (Vigna mungo) cultivars. Indian
J. Agric. Sci., 80 (3), 242-243.
Khadka, D., Lamichhane, S., Shukra, R.S. and Pant, B.B. 2017. Evaluation of soil fertility status of regional
agricultural research station, Tarahara, Sunsari, Nepal. Eurasian J. Soil Sci., 6 (4), 295-306.
Mansour, A.S., Latif, A.A., Zaho, S.M.E. and Abdullah, I.N. 2014. A case study of the total and available
phosphorus concentration in libyan agricultural soils in different depths and seasons in long termchemical and animal manure fertilization. International Journal of Research Studies in Biosciences(IJRSB), 2, 1-9.
Meng, Q., Liu, Z. and Borders, B.E. 2013. Assessment of regression kriging for spatial interpolationcomparisons of seven GIS interpolation methods. Cartogr. Geogr. Inf. Sci., 40, 28-39.
Purdie, B. 1998. Understanding and interpreting soil chemical and physical data. In: Moore, G. (Ed.), Soil
Guide: A Handbook for Understanding and Managing Agricultural Soils, Agriculture Western Australia
Bulletin, No. 4343, Department of Agriculture, Perth, Australia.
Rawal, N., Acharya, K.K., Bam, C.R. and Acharya, K. 2018. Soil fertility mapping of different VDCs of
Sunsari district, Nepal using GIS. Int. J. Appl. Sci. Biotechnol., 6 (2), 142-151.
Shah, A.L., Islam, M.R., Haque, M.M., Ishaque, M. and Miah, M.A.M. 2008. Efficacy of major nutrients inrice production. Bangladesh J. Agril. Res., 33 (3), 639-645.
Stevenson, F.C., Knight, J.D., Wendroth, O., van Kessel, C. and Nielsen, D.R. 2001. A comparison of two
methods to predict the landscape-scale variation of crop yield. Soil Tillage Res., 58, 163-181.
Walkly, A. and Black, I.A. 1934. An examination of the degtjareff method for determining soil organic
matter and a proposed modification of the chromic acid titration method. Soil Sci., 37, 29-38.

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Research article
erd

The Spatial Variability of Soil Chemical Properties
in a Selected Area of Myanmar
NAING NAING MOE*
Department of Soil and Water Science, Yezin Agricultural University, Myanmar
Email: nnmoe148@gmail.com

SWE SWE MAR
Department of Soil and Water Science, Yezin Agricultural University, Myanmar

AUNG KYAW MYINT
Department of Soil and Water Science, Yezin Agricultural University, Myanmar

KYI TOE
Department of Plant Breeding, Physiology and Ecology, Yezin Agricultural University,
Myanmar

KYAW NGWE
Department of Soil and Water Science, Yezin Agricultural University, Myanmar
Received 16 December 2018

Accepted 10 July 2019(*Corresponding Author)

Abstract Sustainable crop production requires detailed knowledge of the spatial variabilityof soil properties, such as soil nutrients. The primary purpose of this study was to assess thestatus of soil fertility by evaluating selected soil chemical properties, at Kyee Inn Village
Tract, Pyinmana Township, Middle Myanmar using Geographic Information Systems (GIS).
In this study soil samples were collected for the 80 grid references examined. Variables
measured were soil pH, electrical conductivity (EC), cation exchange capacity (CEC), soilorganic matter, and the total content of nitrogen and phosphorus. Grid size is 300 m × 300
m, covering an area of about 480 hectares, and samples were taken at a depth of 0-15cm
using a Global Positioning System (GPS) to determine the coordinates of the sampling
points. Soil fertility maps were generated using Inverse Distance Weighting (IDW)
interpolation in ArcGIS software 10.5. Interviews were conducted with farmers to match
results to soil management practices. The statistical analysis demonstrated a high variabilityof total nitrogen content with a coefficient of variation of 66.84%, while the soil pH andphosphorus levels showed the minimum variability in comparison to other soil properties.
The pH values ranged from 5.48 to 7.58, while for phosphorus, minimum to maximum
levels are 0.017% to 0.024%, respectively. Values for EC can be considered normal, with amean value of 0.095 dS m-1 obtained. The CEC values ranged from 2.13 to 11.05 meq100
g-1soil. The low level of organic matter (0.2% to 1.7%) indicated a need to increase theorganic matter content to ensure sustainable crop production. This study provides farmers
with an effective management and decision-making model that encourages sustainable crop
production.
Keywords GIS, GPS, soil chemical properties, spatial variability

INTRODUCTION
Scientists face many challenges in developing strategies to develop sustainable crop production
systems (Bakhsh et al., 2000). Assessing the spatial variability of soil chemical properties is crucial
in the development of these cropping systems (Mamun et al., 2015). Agricultural sustainability
requires that this evaluation of soil fertility should be undertaken periodically (Chimdi et al., 2012).
The spatial variability of soil properties includes the variation of soil chemistry, physics, andⒸ ISERD

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biological properties in a given location. Even for the same soil type, soil characteristics may
exhibit huge differences within short distances (Li et al., 2012).
A standard method for creating maps of topsoil properties is to sample an area using a grid
sampling scheme. The density of sampling undertaken will depend on the heterogeneity of the area.
With this information a ‘prediction’ map can be produced by interpolating the measured property
values of the samples (Karydas et al. 2009). GISs are a powerful set of tools and useful for
producing soil fertility maps for an area, which will help in formulating site-specificrecommendations regarding fertilizer needs, as well as providing an understanding of the status ofsoil fertility both spatially and temporally (Thakor et al., 2014). Inverse Distance Weighting (IDW)
was applied to the data as it is a good interpolator for phenomena whose distribution is strongly
correlated with distance (Mustafa et al., 2011).
Soil fertility is one of the primary constraints to agricultural production in tropical countries,
including Myanmar. Baroang (2013) reported that there is limited information on the dynamics ofsoil types and erosion patterns in Myanmar, and what does exist, is largely based on decades-old
data. The establishment of monitoring stations and the determination of an appropriate monitoring
design would be extremely valuable, as there is an obvious need to update the data concerning
Myanmar soils.
OBJECTIVE
The main objective of this research is to generate accurate large-scale distribution maps of theselected soil properties by evaluating the current soil fertility status of the study area.
METHODOLOGY
Study Area and Soil Sampling
The study area was selected after conducting a pilot survey. The study area covers a total of 480
hectares, and is located at the Kyee Inn Village Tract, Pyinmana Township, in central Myanmar,
and is situated between 1942'30''-1943'40''N and 9613'30''-1915'30''E (Fig. 1). Myanmar
experiences three distinct seasons, hot, wet and cool, and the study area receives a mean annual
rainfall of about 1420 mm and an average temperature of 26.8°C. Monsoon rice and pulses are themain crops, and within the area there is both rain-fed and irrigated farming. The required secondary
data and hardcopy of the base-map of fields in this area are from Department of Agriculture andDepartment of Agricultural Land Management and Statistics. Sampling was done on a grid basis(300 m × 300 m), with samples taken at 0-15 cm depth using GPS to determine the coordinate of
the sampling points. Where possible, three soil samples were taken from each grid to derive a
representative sample. In total, 178 soil samples were collected from the 80 sampling plots (Fig. 2).
All samples were taken after harvest, and before any land preparation for the next cropping season
had been made. Interviews were conducted with farmers in order to identify variations in soil
management practices in different locations in the sample area.
Laboratory Analysis
The collected soil samples were composited for each grid, then air-dried, pounded, and sieved in
preparation for soil analysis. Soil pH and electrical conductivity were measured in the extract ofsoil: water (1:5) suspension using a digital pH-meter and EC meter (Hesse, 1971). Soil CEC wasmeasured using Bascomb’s method (Bascomb, 1964). Total nitrogen was determined by the
Kjeldahl digestion, distillation and titration method (Bremmer and Mulvaney, 1982). The total
phosphorus was analyzed using spectrophotometer as blue molybdate phosphate complexes underpartial reduction with ascorbic acid (Jackson, 1958). The Walkley and Black (1934) wet digestion
method was used to determine soil organic matter.
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Statistical Analysis and Soil Fertility Mapping
The laboratory results of all parameters measured were subjected to descriptive statistic using
Statistix (8th version). The low, medium and high levels of nutrients were determined according tostandard ratings. The base-map preparation enabling use of GIS software was accomplished by dataobtained from a DJI Phantom 4 drone, with this processed using Litchi software. The photos werecombined and processed using pix 4D software for digitizing and incorporated onto the digital basemap. A different thematic map for the spatial distribution of each parameter was generated using
the Inverse Distance Weighted (IDW) interpolation by ArcGIS 10.5 software.
Pyinmana Township

Kyee Inn Village Tract(480 hectares)
1942'30''-1943'40'' N
9613'30''-1915'30''E

Fig. 1 Location of the study area

Fig. 2 Grid sampling points

RESULTS AND DISCUSSION
Spatial Variation in Soil Chemical Properties
The results for each soil parameter over the 80 soil sample sites are presented in Table 1. In the study
area, there is a large variation in soil chemical properties. Total nitrogen showed the highest
variability with 66.84% in its CV (Coefficient of Variation), followed by soil electrical conductivity,with a CV value of 54.36%. However, least variability across sample areas was found for soil pH andtotal phosphorus, with CV values of 5.08% and 6.68% respectively. Moderate variability occurred
for soil CEC and organic matter, which have CV values of 28.02% and 35.93%, respectively.
Table 1 Descriptive statistics of soil chemical properties
Variables
pH
Electrical conductivity
Cation exchange capacity
Organic matter
Total nitrogen
Total phosphorus

Unit*-log[H+]dS m-1
meq100 g-1soil%%%

Minimum
5.480
0.051
2.130
0.200
0.010
0.017

Maximum
7.580
0.506
11.050
1.700
0.330
0.024

Mean
6.248
0.095
6.218
0.874
0.113
0.019

SE
0.03550.00580.19480.03510.00850.0001

SD
0.317
0.052
1.742
0.314
0.076
0.001

CV%
5.08
54.36
28.02
35.93
66.84
6.68

SE: Standard Error, SD: Standard Deviation, CV: Coefficient of Variation* Units represent for the columns of minimum, maximum and mean in the table

Soil pH and Electrical Conductivity
Soils in the study area were found to range from slightly acidic to moderately alkaline, with themean pH value of the soil being 6.25, with a range from 5.48 to 7.58. The pH of the soil samples
can be described as 21.25% moderately acidic, 58.75% slightly acidic, while 18.75% samples were
neutral (pH 7) and only 1.25% samples were moderately alkaline (Fig. 3). The variation in levels of
acidity could be due the topography of the study area, variations in moisture, or farmers’ practice inthe use of acid-forming nitrogenous fertilizers.

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

The values of EC range from 0.051 dS m-1 to 0.505 dS m-1 (Fig. 4). The observed mean EC
value of 0.095 dS m-1 indicated that the study area does not have a salinity problem. According to
Moore (2001), the observed EC values were only just above the low range of levels for EC values
that is between 0.051 and 0.5 dS m-1, a level expected to have a minimum effect on plant growth.

EC (dS m-1)

Fig. 3 Spatial distribution of soil pH

Fig. 4 Spatial distribution of EC

Cation Exchange Capacity and Soil Organic Matter
The observed CEC vary from a low to a medium level, ranging from 2.13 to 11.05 meq100 g-1 soil,
with a mean value of 6.22 meq100 g-1 soil, for the study area (Fig. 5). Using Landon’s (1991)
classificatory system, 23.75% could be characterized as very low in CEC, while the remaining
76.25% has a low level of CEC. This would indicate that the study area has inadequate basic
cations which would be detrimental to plant growth. Ahmed et al. (2015) stated that any CEC of <4
meq100g-1 soil indicates a high degree of soil infertility, making it unsuitable for agriculture.
Organic matter content ranges from 0.20% to 1.70%, with a mean value of 0.87%. Figure 6
displayed the spatial distribution of organic matter (in OM%) with lowest levels in the northeastand eastern portion, with content increasing towards the southwest. This may be the result of theslightly higher elevation of the northern portion, as organic matter accumulation is often favored inthose areas at lower levels. Purdie (1998) states that soils with organic matter content greater than
2.6% provide good nutrient storage, so it can be seen that the level of organic matter content in all
sampling grid plots was very low, affecting good nutrient storage and supply. Based on the surveyof farmers’ soil management practices, this lower organic matter content may be attributed to poor
agricultural management practices, such as the complete removal of crop residues after harvest andthe infrequent application of organic manures and organic materials (rice straw, pulses residues,
cow dung, etc.) and the burning of crop residues after harvesting.

CEC(meq100 g-1soil)

Fig. 5 Spatial distribution of CEC

Fig. 6 Spatial distribution of OMⒸ ISERD

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Total Nitrogen and Total Phosphorus
The total nitrogen content varied from 0.01% to 0.33% with a mean value of 0.11% overall. The
study indicates that about 25% of the area sampled has ‘very low’ levels of nitrogen and a further
50% has ‘low’ levels, while 17.5% of the samples are in the medium range, and only 7.5% have ahigh range of total nitrogen content (Fig. 7). The low nitrogen content is probably due to theinsufficient level of organic matter, which can be depleted by constant cropping and prevailinghigh temperatures, resulting in the faster degradation and removal of organic matter, with acorresponding drop in the soil’s nitrogen reserves. On the other hand, the areas of medium to highlevel of total nitrogen appear to occur where organic materials have been added (mainly plant
residues), and also as a result of nitrogen fixed through legume cultivation.
The spatial distribution of total phosphorus levels appears to be higher, with 43.75% of thesampling area being in the medium range, whereas 56.25% of the samples showed lower levels (Fig.
8). The values of total phosphorus ranged from 0.017% to 0.024% with a mean value of 0.019%.
According to research, lower levels of phosphorus may be due to infrequent application of organicand inorganic phosphorus fertilizers. Another reason for these lower levels may be due to nutrient
depletion by crops, since this area has a cropping pattern of monsoon rice and dry weather pulses.

Fig. 7 Spatial distribution of total N

Fig. 8 Spatial distribution of total P

Survey Results for Soil Management Practices
Mostly preparation of land for cropping is mechanized, with only 21% of respondents using bothmachine and animal power. In this area, the dominant cropping pattern of monsoon rice and pulses
is practiced under both rain-fed and irrigated farming. It was found that there is minimal
application of organic fertilizers. After harvesting, farmers retain residues from the pulse crop on
their fields, but this is done by a minority. About 23% of respondents use cow-dung manure andonly 12% of respondents apply pulses residues. The most common types of inorganic fertilizers
used by the respondents were urea and compound fertilizers for rice production. There is noevidence of the application of phosphorus and potash fertilizers for crop production. Application offertilizers is mostly by the broadcast method and top dressing is applied two to three times, at thetillering and flowering stages. Fertilizers do not appear to be applied basally at planting time.
CONCLUSION
Results from the soil analysis show the following characteristics of the soil in the study area; it has
low content of organic matter, it has (mostly) low to high levels of total nitrogen, low to medium
ranges of total phosphorus, while the level of the CEC is very low to low. Although the measured
ranges of soil pH and electrical conductivity ranges should not be detrimental to the crop
cultivation, soil nutrient management for sustainable crop production should focus on addressing
problems of acidity and alkalinity. As expected, the variability of each soil characteristic exists
largely due to the differences in the management practices used by farmers. Therefore, farmers
should be encouraged to return as much crop residue as possible to the soil, introducing systematicⒸ ISERD

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practices (sufficient and consistent) that provide for the addition of manure and fertilizers, in orderto improve soil fertility levels which will lead to higher crop production. Further, a legume-based
cropping pattern should also be introduced and consistently maintained to provide a long-term
nutrient supply for better yields and diversify the economics of crop production. This study has
shown that the use of new technologies such as GIS and GPS can provide important informationfor evaluating the current status of soil fertility, and for allowing better management of soil fertility
at the farm level.
ACKNOWLEDGEMENTS
We would like to gratefully acknowledge the Japan International Cooperation Agency (JICA), who
supervise the Project for Capacity Development of Yezin Agricultural University, and who haveprovided technical and financial support for this study. We would also like to thank staff at the
Department of Agriculture and Department of Agricultural Land Management and Statistics, forthe maps and data that were provided. Assistance was provided in drone flying, photo processing
and the generation of maps, and the analysis of samples. Finally, we are very grateful to thefarmers in the study area for their keen participation throughout the study.
REFERENCES
Ahmed, M., Jeb, D., Usman, A., Adamu, G. and Mohammed, M. 2015. Spatial distribution and assessment of
selected soil physiochemical parameters using GIS techniques in Bunkure Kano State. Nigeria
International Journal of Plant & Soil Science, 5 (3), 143-154.
Bakhsh, A., Colvin, T.S., Jaynes, D.B., Kanwar, R.S. and Tim, U.S. 2000. Using soil attributes and GIS forinterpretation of spatial variability in yield. Transactions of the ASAE, 43 (4), 819.
Baroang, K. 2013. Myanmar bio-physical characterization, Summary findings and issues to explore.
Michigan State University, USA.
Bascomb, C.L. 1964. Rapid method for the determination of cation‐exchange capacity of calcareous and non‐calcareous soils. Journal of the Science of Food and Agriculture, 15 (12), 821-823.
Bremner, J.M. and Mulvaney, C.S. 1982. Nitrogen-total 1. Methods of soil analysis. Part 2. Chemical andmicrobiological properties, (methodsofsoilan2). 595-624.
Chimdi, A., Gebrekidan, H., Kibret, K. and Tadesse, A. 2012. Status of selected physicochemical properties
of soils under different land use systems of Western Oromia, Ethiopia. Journal of Biodiversity andEnvironmental Sciences, 2 (3), 57-71.
Hesse, P.R. 1971. A textbook of soil chemical analysis. John Murray, London.
Jackson, M.L. 1958. Soil chemical analysis. Prentice Hall. Inc., Englewood Cliffs, NJ. 498.
Karydas, C.G., Gitas, I.Z., Koutsogiannaki, E., Lydakis-Simantiris, N. and Silleos, G.N. 2009. Evaluation of
spatial interpolation techniques for mapping agricultural topsoil properties in Crete. EARSeL
eProceedings, 8 (1), 26-39.
Landon, J.R. 1991. Booker tropical soil manual, A handbook for soil survey and agricultural land evaluationin the tropics and subtropics. Longman Scientific and Technical, Essex, New York, USA. 474.
Li, C., Chen, G., Zeng, G. and Ye, J. 2012. The study of soil fertility spatial variation feature based on GIS
and data mining. Int. Conf. on Computer and Computing Technology in Agriculture, Berlin, 211-220.
Mamun, M.A.A., Haque, M.M., Khaliq, Q.A., Karim, M.A., Karim, A.J.M.S., Mridha, A.J. and Saleque,M.A. 2015. Assessment of soil chemical properties and rice yield in tidal submergence ecosystem.
Bangladesh Agronomy Journal, 18 (2), 79-87.
Moore, G.A. 2001. Soil guide, A handbook for understanding and managing agricultural soils. Department ofAgriculture and Food, Perth, Western Australia.
Mustafa, A.A., Singh, M., Sahoo, R.N., Ahmed, N., Khanna, M., Sarangi, A. and Mishra, A.K. 2011. Land
suitability analysis for different crops, A multi criteria decision making approach using remote sensing
and GIS. Researcher, 3 (12), 61-84.
Purdie, B. 1998. Understanding and interpreting soil chemical and physical data. In: Moore, G. (Ed.), Soil
Guide: A Handbook for Understanding and Managing Agricultural Soils. Agriculture Western Australia
Bulletin, No. 4343. Department of Agriculture, Perth, Australia.

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Thakor, K.M., Dharaiya, N., Singh, V., Patel, A., Mehmood, K. and Kalubarme, M.H. 2014. Soil resources
information system for improving productivity using geo-Informatics technology. International Journal of
Geosciences, 5, 771-784.
Walkley, A. and Black, I.A. 1934. An examination of the Degtjareff method for determining soil organic
matter, and a proposed modification of the chromic acid titration method. Soil Sci., 37 (1), 29-38.

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Research article
erdParticipatory Risk Assessment of Nong Han Wetland,
ThailandPRAJYA NGAMJAN*
Kasetsart University, Chalermpharakiat Sakon Nakhon Province Campus, Sakon Nakhon,
Thailand
Email: prachya.ng@ku.th

THODSAPOL CHATURABUL
Kasetsart University, Chalermpharakiat Sakon Nakhon Province Campus, Sakon Nakhon,
ThailandReceived 30 December 2018

Accepted 30 July 2019(*Corresponding Author)

Abstract Recognised as a Wetland of International Importance, the Nong Han Wetland(NHW), in Sakon Nakhon, Thailand, was selected as a study site for a risk assessment,
which is an integral part of wetland management planning. The study demonstrated theprocess and presented the results of a risk assessment adopted in the NHW. The research
postulates a simple risk assessment framework, where stakeholder participation is the key
element. Following Ramsar’s guideline, tailored to suit the objectives of the study, the risk
assessment framework involved (1) identifying problems and risks; (2) quantifying risks;and (3) proposing prevention and mitigation measures. Data were collected via focus groupand questionnaire. The total number of participants was 217 stakeholders from 49 villages
in the NHW. Eleven issues were identified, namely: (1) an increase in aquatic plant growth;(2) sedimentation; (3) degradation of water quality; (4) reduction and extinction ofindigenous fish species; (5) non-existence of water laws; (6) land-rights; (7) conflicts ofjoint natural resource utilization; (8) sufficiency of data and information; (9) flooding; (10)draught; and (11) climate change. Risks were evaluated and ranked in terms of risk
perception, and participants from different locations perceived degrees of risk rather
differently. Nonetheless, when all the participants were analysed integratedly, the highest
common risks shared were an increase in aquatic plant growth, sedimentation, degradationof water quality, and reduction and extinction of indigenous fish species. In addition, a setof risk prevention and mitigation measures was also drawn from the participatory risk
assessment process. The results could be employed as a guideline for future plans andinterventions of the wetland management following the bottom-up approach adhered to theIntegrated Water Resources Management (IWRM) principles. The process not only drew
conclusions and recommendations regarding risk management, but also created risk
awareness and enhanced the degree of stakeholder engagement.
Keywords Nong Han Wetland, participatory risk assessment, risk perception, Integrated
Water Resources Management

INTRODUCTION
Nong Han Wetland (NHW), in Sakon Nakhon Province, Thailand, has been recognized as a
Wetland of International Importance (MNRE, 2009). It is the largest natural lake in the northeast of
Thailand and the country’s second largest after Bueng Boraphet, Nakhon Sawan Province. The
NHW connects to the Mekong River via the Nam Kam River, approximately 123 kilometres inlength. The location of the NHW is shown in Fig. 1. The Nong Han Basin covers the area of 583
km2, where the wetland covers the area of 123 km2 with an average depth of 1.9 m., composing
paddy fields, grass lands, and village communities (Chaturabul and Pongput, 2013). Abundant innatural resources, Nong Han is a complex and important ecosystem and is vital to the livelihoods ofthe local communities (MRC, 2017).
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The NHW has been managed by various governmental agencies. Due to various factors,
mainly anthropic disturbance, various issues have been reported, namely, floods, draught,
degradation of water quality, increases in aquatic plants, sedimentation, and the reduction andextinction of indigenous fish species (MRC, 2017). This demands a well-integrated plan for thewetland management, whereas risk assessment is an integral part of the management-planning
processes for wetlands (Ramsar, 1999). In addition, prior to this study, a risk analysis had neverbeen conducted on the NHW. This research therefore is a first attempt at a risk analysis of Nong
Han by employing a participatory risk assessment methodology, which is a bottom-up approach
involving local communities in identifying, deciding solution measures, and implementing andevaluating interventions. It is well noted that participation from stakeholders is important to thesuccess of policy implementation (see for example Erftemeijer and Bualuang, 2002; Trisurat. 2006).

Fig. 1 Location of Nong Han Wetland
OBJECTIVES
The objectives of this study are: (1) to present a comprehensive risk analysis of the NHW; (2) todetermine the pressures and impacts on the environment and community livelihoods in the NHW;
(3) to propose prevention and mitigation measures of the risks elicited by the participants; and (4)to promote a community participatory approach and capacitate stakeholders with integrated water
resource methodology.
METHODOLOGY
The study adopted the risk assessment framework of the Wetland Risk Assessment proposed by the
Ramsar Convention Secretariat (1999) tailored to suit the scope of the study, as shown in Fig. 2 below.
(1) Identify
problems and risks(2) Quantify risks(3) Propose prevention
and mitigation measures

Fig. 2 Risk assessment frameworkⒸ ISERD

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The analysis combined both qualitative and quantitative methods. Qualitatively, in order togather primary data, focus groups were organised. Quantitatively, the information drawn wasquantified in terms of risk ranking. Stakeholder participation was key in all steps. The process isoutlined herewith.
1. Identify Problems and Risks
Closely related, problems and risk identifications were carried out hand-in-hand. Problems can be
defined as undesired incidents, whereas associated risks are the corresponding consequences andlikelihoods. Problems and risks were initially formulated in a series of workshops, held by a civilsociety in Sakon Nakhon called the Chomrom Song Serm Kon Dee, consisting of direct
stakeholders, including civil servants, business owners, and community residents.
Eleven issues were identified: 1. an increase in aquatic plant growth; 2. sedimentation; 3.
degradation of water quality; 4. reduction and extinction of indigenous fish species; 5. lack of water
laws; 6. land-rights issues; 7. conflicts of joint natural resource utilization; 8. existence of andsufficiency of data and information; 9. floods; 10. draught; and 11. climate change. These issues
were later introduced to the other four workshops organized in the NHW in order to gather
agreements and additional issues from the participants.
2. Quantify Risks
Risk perception methodology was employed. Risk perception refers to human subjective judgments
about the likelihood of negative occurrences such as hazards and threats to the environment or
health (Paek and Hove, 2017). In other words, it indicates the extent to which people know, andwhat they feel, about threats and likelihoods, and gives a general overview of the status quo of risks
pertaining to environmental settings.
There are various methods for quantifying risk perception (see e.g. Weber et al., 2002; andJanmaimool and Watanabe, 2014). This study devised a simple, straight-forward and low-cost
method. First, the questionnaire was designed around the issues identified in the previous step.
Eleven close-ended questions required the respondents to subjectively evaluate the degree of risks
and the likelihood of the issues to occur. Second, response options were coded as “High = 3,”“Moderate = 2,” and “Low = 1.” Then, risk and likeliness were arithmetically averaged, and scaled
to the range of 0 to 1.
3. Prevention and Mitigation Measures
During the workshops, the participants were asked to participate in a group discussion and toactively participate and exchange their ideas on the related prevention and mitigation measures.
Table 1 Workshop participants and venues
Venue (all in Sakon Nakhon Province)
Phon Na Kaew District Hall, Phone Na Kaew District
Lao Po Daeng Sub-district Municipality, Muang District
Chiang Khruea Sub-district Municipality, Muang District
Sakon Nakhon City Municipality, Muang District
Total

Respondent
50
57
49
61
217

Village
11
16
12
10
49

Sub-district
3
4
3
1
11

4. Risk Analysis Workshop
Four workshops were organised to collect data from the communities in four different locations
around Nong Han during 2016. Table 1 and Fig. 3, respectively, illustrate and report the numbersof participants, villages, and sub-districts they represented. The total number of participants wasⒸ ISERD

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

217, including direct stakeholders, such as sub-district headsmen, village chiefs and assistants, andvillage committees.

Fig. 3 Study site and workshop venue
RESULTS AND DISCUSSION
This section presents the results; namely, risk logs, prevention and mitigation measures, and discussion.
1. Risk Log
The risk log summarized the results of the risk analysis in terms of likely impacts on theenvironment and community of the NHW.
Table 2 Ranked risk log
No.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.

Issue
Increase in aquatic plant growth
Sedimentation
Degradation of water quality
Reduction and extinction of indigenous fish species
Land-rights issue
Climate change
Draught
Conflicts of joint natural resources utilization
Nong Han’s data and information sufficiency
Lack of water law
FloodⒸ ISERD30

Impact
0.94
0.93
0.92
0.88
0.88
0.87
0.85
0.83
0.83
0.80
0.80

Likelihood
0.96
0.94
0.93
0.90
0.88
0.88
0.87
0.84
0.83
0.82
0.80

Rating
0.90
0.87
0.85
0.79
0.78
0.77
0.74
0.70
0.69
0.66
0.64

IJERD – International Journal of Environmental and Rural Development (2019) 10-2

The first four highest-ranked issues were all closely related. Issues such as sufficiency of dataand information about Nong Han, lack of water law, and flooding were ranked last, but they werestill considered high both in terms of impact and likelihood.
2. Prevention and Mitigation Measures
The proposed prevention and mitigation measures were the result of stakeholder participation incollectively eliciting solutions to the common problems shared. The measures are classified
herewith as structural and non-structural. On the one hand, structural measures are fixed or
permanent physical constructions for preventing and mitigating risks. On the other hand, nonstructural measures do not involve physical facilities. Due to the limited space, the measures are
only briefly summarised as follows.
2.1 Structural Prevention and Mitigation Measures

Build more wastewater treatment plants (at the present, there are only two plants in the NHW).
Build adequate drainage systems and improve the existing drainage systems.
Build an embankment/dike, construct more reservoirs to increase water storage, and constructroads surrounding Nong Han.

2.2 Non-Structural Prevention and Mitigation Measures
These non-structural prevention and mitigation measures are grouped into 1) regulatory measures;2) awareness and education measures; and 3) non-structural modifications.
Regulatory measures:
 Enact and enforce water laws or water resources agreements, namely, Nong Han
agreements/laws to conserve fish species and to prescribe penalties for violations.
 Amend the existing law, the Royal Decree of Demarcation of Restricted Land in Muang
District, Sakon Nakhon Province B.E.2484 (1941), to solve land rights conflicts in the NHW.
Awareness and education measures: Create awareness and involvement, and disseminate knowledge of integrated water resource
management and how to use water wisely and equitably.
 Campaign stakeholders to prevent pollution of the NHW.
 Promote organic farming, stop/reduce using chemical fertilizer and pesticides.
 Promote reforestation and preserve the existing natural resources.
 Create awareness and conserve the population of indigenous fish species, and campaign forsustainable fishing.
 Organise discussions between the government and the people in order to improve common
understanding.
 Create a data-management centre in order to organise studies and data collection, and to
publicise accurate data and information.
Nonstructural modifications: Employ natural methods to treat wastewater, e.g., use mosquito fern or water fern to absorb heavy
metals and phosphates, and increase herbivorous fish species that feed on aquatic vegetation.
 Remove and control aquatic weed for example through dredging operations and weed removal
machines.
 Plant and maintain an appropriate vegetative buffer on the shoreline to prevent soil erosion andsedimentation.

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

CONCLUSIONSIn addition to the measures introduced above, the participants also recommended developing aNong Han management plan, which should include draught protection and relief, and flood
prevention, protection, and mitigation. On the one hand, engineered structures may eliminate therisk to some degree. On the other hand, non-structural measures are less costly and requireparticipation through a process of behaviour influencing, usually via stakeholder capacity building(Taylor and Wong, 2002). Both structural and non-structural measures recommended from thisstudy can be employed as a part of wetland management planning. Importantly, the two measures
should be balanced; for structural measures to be effective, stakeholders should be aware, prepared,
and duly trained (Bons, 2013). The participatory risk assessment procedures proposed can be
employed in different environmental management planning settings. The study not only drew
conclusions and made recommendations regarding risk management, but also created risk
awareness and enhanced the degree of stakeholder engagement.
ACKNOWLEDGEMENTS
This research is a part of the “Transboundary Cooperation for River Basin Management between
Lao PDR and Thailand in Xe-Bang-Hieng of Lao PDR and Nam Kam of Thailand (NK-XBH)
Project,” which is one of the five transboundary MIWRM (Mekong Integrated Water Resources
Management) projects facilitated by the Thai National Mekong Committee (TNMC), the MekongRiver Commission (MRC), and funded by the World Bank.
The authors would like to thank Ms Panporn Suwan, Thai National Mekong Committee
Secretariat (TNMCS), and Dr. Piriya Uraiwong, Mekong River Commission Secretariat (MRCS),
for their constructive comments, help, and support. The first author would also like to especiallythank Mr. Sansonthi Boonyothayan, the Thai National Consultant of the NK-XBH Project. Last but
not least, gratitude also goes to all of the workshop participants for their enthusiastic and active
cooperation and input. All errors, should there be any, are solely our responsibility.
REFERENCES
Bons, K. 2013. Comparing structural and non-structural measures. Flood Risk Management and Urban
Resilience Workshop II, May 28-29, 2013, Seoul, Korea.
Chaturabul, T. and Pongput, K. 2013. Nong Han: A physical view. In Lesson Learnt from Nong Han. Sopsan
Petchkam (Ed.), Pornsiri Publishing, 32-51. (in Thai)
Erftemeijer, P.L.A. and Bualuang, A. 2002. Participation of local communities in mangrove forest
rehabilitation in Pattani Bay, Thailand, Learning from successes and failures. In: Gawler, M. (Ed.)
Strategies for Wise Use of Wetlands: Best Practices in Participatory Management, Proceedings of aWorkshop held at the 2nd International Conference on Wetlands and Development, Wetlands
International, IUCN, WWF Publication, 56, Wageningen, Netherlands, 27-36. Retrieved fromhttp://globalrestorationnetwork.org/uploads/files/CaseStudyAttachments/54_pattani-bay. pdf
Janmaimool, P. and Watanabe, T. 2014. Evaluating determinants of environmental risk perception for risk
management in contaminated sites. International Journal of Environmental Research and Public Health.
11 (6), 6291-6313.
Mekong River Commission. 2017. Trans-boundary cooperation for river basin management between Lao
PDR and Thailand in Xe Bang Hieng Basin-Lao PDR and Nam Kam Basin-Thailand. Joint Report on
Wetland Management between Xe Champhone-Lao PDR and Nong Han-Thailand project.
Ministry of Natural Resources and Environment. 2009. Revised directory of wetlands of national andinternational importance of Thailand, and management measures for wetland conservation. Cabinet
resolution 2552 B.E. http://chm-thai.onep.go.th/wetland/pdf/cabinet3Nov2009.pdf. (in Thai)
Paek, Hye-Jin. and Hove, T. 2017. Risk perceptions and risk characteristics. Oxford Research Enclycopedia.
Ramsar Convention Secretariat. 1999. Wetland risk assessment framework: Resolution VII.10. People andwetlands. The Vital Link, 7th Meeting of the Conference of the Contracting Parties to the Convention on
Wetlands (Ramsar, Iran, 1971), San José, Costa Rica, 10-18 May 1999.
Taylor, A. and Wong, T. 2002. Non-structural stormwater quality best management practices, An overviewⒸ ISERD

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2of their use, value, cost and evaluation. Cooperative Research Centre for Catchment Hydrology.
Technical Report 02/11, https://ewater.org.au/archive/crcch/archive/pubs/pdfs/technical200211.pdf.
Trisurat, Y. 2006. Community-based wetland management in northern Thailand. International Journal ofEnvironmental, Cultural, Economic and Social Sustainability, 2, 49-62.
Weber, E.U., Blais, A.R. and Betz, N.E. 2002. A domain-speciﬁc risk-attitude scale, Measuring risk
perceptions and risk behaviors. Journal of Behavioral Decision Making, 15, 263-290.

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

Research article
erd

Development of Ecotourism in North Bandung, Indonesia
FARIDAH SITI*Division of Environmental Studies, Graduate School of Frontier Sciences,
The University of Tokyo, Kashiwa, Japan
Email: 9514846365@edu.k.u-tokyo.ac.jp

EIJI YAMAJI
Division of Environmental Studies, Graduate School of Frontier Sciences,
The University of Tokyo, Kashiwa, Japan
Received 19 December 2018

Accepted 30 July 2019(*Corresponding Author)

Abstract Ecotourism has been used to be an alternative for tourism activity while
maintaining its natural sustainability. The spread of ecotourism in North Bandung that
increased by number not only boosted the development of village area but also hoped to beable to improve the welfare of people living near tourist sites. This study looks at the
tourism site's development and specializes in discussions on two tourist sites, Orchid Forest
Cikole and Taman Bunga Begonia “Glory.” Literatures findings suggest awareness about
environmental quality, education, and involvement of the local community, becoming a
possible substance to be a benchmark of measurement of ecotourism concept. By using thatmeasurement, this study seeks named sites ecotourism management and conditions byconducting in depth interviews with the tourism site owner and site marketing team leader.
The result shows that even though some efforts are still in the planning stage, Orchid Forest
Cikole has implemented quite several efforts to carry out the value of the ecotourism
concept. Meanwhile, Taman Bunga Begonia “Glory” tourist sites, even though the land
owned is relatively small and its starting from a hobby, this site applies a lot of the value of
ecotourism concept.
Keywords ecotourism, land use, rural development, leisure park, sustainability

INTRODUCTION
While it has been actively promoting around the world, Indonesia has been particularly keen on
developing ecotourism, by naming the year 2002 their “National Ecotourism Year.” Indonesia is
known for its rich biodiversity and cultural diversity. The country promotes ecotourism with thehigh hope that ecotourism will provide alternative ways to use such diversities sustainably andeconomically and to improve the living standards of Indonesia’s people (Izawa, 2010).
Ecotourism in Indonesia defined as activities of responsible traveling in whole areas or inareas that are named according to the role of nature. The purpose of such activities is: being toenjoy natural beauty involving education, understanding, and supports conservation, as well as
increasing the income of the local communities. Its importance is (1) to generate jobs and revenue,
which can provide an incentive for preserving natural areas. Then, (2) to raise public awareness ofthe many products and services provided by natural ecosystems biological resources and respect fortraditional knowledge and practices, and (3) to reconcile economic and environmental concerns andgive practical meaning to sustainable development (Nirwandar, 2015).
Ecotourism has become a global issue that is often discussed in Indonesia. It is one of thespecial activities of tourism which its interest is the low impact on natural tourism (Butarbutar &Soemarno, 2013). It has been used to be an alternative for tourism activity while maintaining its
natural sustainability. The spread and development of the tourism site certainly provide many
positive impacts. However, it may also harm natural resources and does not make a significant
contribution to local residents. As Indonesia’s international and domestic tourism growth continues,
there will be even greater stress on what are, in some cases, already threatened or vulnerableⒸ ISERD

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

natural and cultural environments. Places urgency on the need to increase the awareness andpractices for sustainable tourism approaches by industry and tourists alike (ILO, 2012).
However, within recent tourism progress, there was a concern whether the northern Bandungarea is it still able to maintain its function as a conservation forest. It is nearly difficult to apply
forest revitalization as a solution. As the nearest approach to new conditions, the study about it isecotourism and sustainability may be one option to know the new condition, which will lead toecotourism that is more environmentally friendly. In this paper, ecotourism in the North Bandungarea, especially Orchid Forest Cikole and Taman Bunga Begonia “Glory,” will be described. The
reason two places become the object of study is because of both popularity and the backgroundstory behind the success.
OBJECTIVE
This study attempts to identify available information on ecotourism schemes background and the site's
effort to maintain its ecotourism concept by measuring it into its “Environmental conservation efforts,”“Cultural preservation efforts,” and “Efforts to involve local communities and improve their welfare.”
METHODOLOGY
The methodology consists of a literature review, interview, and analysis part. Qualitative methods
were used to determine the value of ecotourism in Orchid Forest Cikole and Taman Bunga Begonia“Glory” (from now on referred to as “OFC” and “TBB”), then measure the roles of the tourism
sites and the local communities. Interviewing the owner of TBB and marketing team leader OFC
was done on 17th July 2018. The interview was conducted by concerning the ecotourism criteria
and indicator (Table 1) that Yanuarti and Rosyidie (2008) use as a parameter of ecotourism. The
three key indicators were as follows.
Table 1 Ecotourism criteria and indicator (Yanuarti and Rosyidie, 2008)
Environmental Conservation Efforts
Develop eco-friendly tourism facilities using natural materials (wood or bamboo)
Involving tourists to conduct activities
Financial assistance from tourists for conservation activities
Use of alternative resources, such as utilization of water for electricity, wood for fuel, etc.
Waste management, reduce the use of materials that can not be recycled such as plastics, cans, andaluminum that pollute the environment
Engage in ecological revitalization treatment
Cultural Preservation Efforts
Presentation of local arts and cultural attractions
Sale of handicrafts or souvenirs with local nuances
Local Communities Involvement and Welfare Improvement Efforts
Engaging local communities in the planning and development process region
Engagement of people who work in tourist sites
Involvement of the community as an entrepreneur or manager of accommodation services, attractions,transportation, and other supporting services
Involvement of the community as a marketing force, promotion and tour guide
The community is given an opportunity by the owner to obtain education and training of tourism area
management

RESULTS AND DISCUSSION
Conditions of North Bandung Area
As mentioned before, the land use condition is also affected by Bandung city development. The
high rite of urban sprawl ignites the phenomena of land conversion and becoming an essential issue
to environmental change. According to Masri (2009), 28.11% of house development in Lembang isdeveloping at an improper zone for residential lands. The vast area, environmental convenient, road
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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

accessibility, accessibility have a positive correlation to the community choose to stay in the
housing development at lousy zone. Traffic jam, water, and air pollution, land degradation, flora,
and fauna lose so that decreasing environmental quality.
Current Tourism Development in Orchid Forest Cikole (OFC)
OFC is standing on 14 ha of pine forest land in Cikole Lembang District West Bandung regency, a
new tourist destination with a collection of 157 rare orchids from all around the world. The location
is approximately 7 kilometers north of Lembang, right before the entrance to Mount Tangkuban
Perahu and across the Jayagiri camping site.
This site introduced as a recreation park that started in October 2017, which is located in Jalan
Genteng, Tangkuban Perahu Cikole Km.8 Lembang Kab. Bandung Barat. The entrance fee for thissite costs 30.000 IDR and 15.000 IDR if the visitor wants to experience some additional attraction.
Based on news articles, the average number of visitors is 1000 visitors a day, and it can increase to
10.000 visitors on a national holiday like the Eid al Fitr holiday. The reason why this site becomesan interview target is that this site is targeted not only as of the tourism object, it is also as become
center of cultivation, conservation, and orchid flowering. Within the concept of geo-tourism andeco-tourism, Perhutani seeks to preserve nature as well as lifting society's economy. Since it newly
opened, the information is limited and cannot be attained due to it still in development progress.
Current Tourism Development in Taman Bunga Begonia “Glory” (TBB)
Before becoming into a recreation park, this parkland bought by the owner; it was an area that was notgetting attention and in the form of a corn garden with 1ha areas. An individual land commonly used tohold a night market. Previously the owner was a farmworker in the Netherlands who aspired to be able
to manage agriculture in Lembang in his retirement. From the beginning, the owner planned to growflowers because the climate was suitable for flower planting. Famous for its excellent performance,
many enthusiasts interested especially housewives who come and say "this place is like in Europe," takepictures and enjoy the park. The demand for planting begonias also increases.
It is starting from 2013, this site introduced as a recreation park. The entrance fee for this site
costs 5.000 IDR back at 2013, and 20.000 IDR today. Its average visitor on a weekday is 300
visitors, 1000 visitors on weekend or national holiday. The owner explained that the management
cost for the park is 40% from earned income. The reason why this site becomes an interview target
is that is due to its development which started from its owner hobbies to take care of flower andslowly to become a tourism park. The people like the beauty, the amount of interest, and the rapid
dissemination of information from social media have changed this location, which was initially apark and greenhouse to be like today.
Evaluation on Ecotourism by Three Indicators
1. Environmental Conservation Efforts
In environmental conservation effort, both sites develop the eco-friendly tourism facilities. In this
implementation, OFC facilities are 80% using natural woods from the tourism area site, and also
for its construction process, this site not allowed to use any heavy machinery. This site chose andmade sure the felled trees are a tree that old enough following the direction from Perhutani(Indonesian State Forest Company). Felled trees are also used to be tourism facilities (sightseeing
sky bridge, high rope, others) and supported by other construction hard materials. Limited by its
space, as much as possible, TBB does not use massive buildings, and most of the facilities
contained here are bamboo-based, except the management office made of fixed buildings.
Even though its form as an attraction OFC provides several activities that can be conducted by
the visitor such as outbound facilities (such as flying fox, high rope, zip line, the garden of light),
but an additional fee also charged. On the contrary, TBB provides training involve tourists toⒸ ISERD

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

conduct activities and direction for flower planting for the prospective retiree as a venue for sharing
experiences, learning the place for the student regarding flower and vegetable planting. This site isalso open a sharing discussion for local area family empowerment-welfare housewives group.

Figs. 1 and 2 OFC using natural woods from tourism area site

Fig. 3 Restaurant in TBBBoth sites still depend on third party electricity providers to facilitate maintenance. Althoughpreviously TBB had planned to raise cattle to make biogas installations. However, its application isquite inconvenient. The grass for its feed is quite difficult to find based on information fromfarmers around who have difficulty finding grass in the dry season. Also, there have been noattempts of financial assistance from tourists for conservation activities. Most visitors come forsightseeing purposes.
An effort to reduce the use of materials that cannot be recycled and can pollute theenvironment, OFC applied it by imposes a ban on bringing food from outside, on reducing thechance of visitors leaving trash in the tourist area. Therefore, provision of coffee shops andcanteens facilities which also promote the ecotourism concept by not using styrofoam, and sorting
plastic waste. As for TBB, generally, waste from the park is destroyed as compost. The plastic
waste and cans are partly tried to be burned with incinerators to break down pollution poisons. The
begonia park owns the equipment, but currently, it is still under development so that thetemperature produced by the incinerator remains stable.
As for engagement in ecological revitalization, treatment OFC focuses on the ecologicalrevitalization of orchids and also organizes educational tours on orchid treatments. It is also
expected to be a lesson to maintain a sustainable balance between orchids and forests. An orchid
decorates about 70% of the pine trees found on this site at each tree, and a have facility specificallyfor orchid cultivation. On the other hand, TBB owner's efforts and expectation by owning this park
are to keep and conserve the area as a park, then avoid to build a building is one of his ways toengage in ecological revitalization treatment.

Fig. 4 A tree decorated
Fig. 5 TBB that avoiding to buildwith orchids at OFC
a massive building on it site

Fig. 6 Souvenir shop
corner in TBB

2. Cultural Preservation Efforts
So far, there has been no preservation of local culture and art in OFC since the site is relatively new.
For the future, the manager plans to cooperate with schools and make the students be able toⒸ ISERD

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

showcase traditional cultural arts dance at the event held here. As for the official souvenir, it is stillin design progress and still in the process of market research.
In the TBB site, there is room to trade local products. There are also plant that is entrusted by
the local farmers to sell here. Since the area is only one hectare and relatively small, this park does
not have facilities like a stage for performances.
3. Local Communities Involvement and Welfare Improvement Efforts
Both sites were employing 80-90 percent of young staff from residents as an effort to engage local
communities. Although for OFC, the planning and development still the leading directors whocarried out the process. The collaboration has been carried out primarily with Perhutani. Thus, theinvolvement of the community in another aspect is still not implemented. However, in the future,
OFC plans to be able to collaborate with local entrepreneurs. Therefore, that other workshops canbe held and provide opportunities to market products from local entrepreneurs. So far, thepromotion has been influenced more by the high interest of visitors due the social media posts ofpeople who have previously visited.
On the contrary, TBB, the owner, involves planning with local people to help each other in tosell plants. For example, with the craftsmen of flower pots, flower farmers around. There are someof the residents also offer services such as offering horse riding services, selling pet products suchas rabbits around the park location as the involvement of the community as an entrepreneur ormanager of accommodation services, attractions, transportation, and other supporting services.
For involvement of the community as a marketing force, promotion, and tour guide case, since
the parking area considered small, it has a problem in the parking area. When there is a difficulty inparking lots from high visitors, residents around the park who have a house yard, vacant land
empowered as an alternative parking lot. By this mutual concession, the park owner hopes it cancontribute so that they can get additional income. Rather than to the community, the owner is more
likely to provide internal education to local staff who are in direct contact with the park to provide
better jobs related tourism as allowed by the owner to obtain education and training of tourism area
management. As an example, like the application of 5R (Ringkas = concise, Rapi = neat, Resik =clean, Rawat = care, Rajin = persevere) that adapts from the 5S of Japan (JICA, n.d). Due to thelack of general tourism ideas of the local community.
According to the interview obtained data, the comparison between two site's efforts are
summarized in Table 2.
Table 2 Interview result comparison
Environmental Conservation Efforts
Orchid (OFC)
Develop eco-friendly tourism facilities using natural materials (wood or bamboo)
Involving tourists to conduct activities
Δ
Financial assistance from tourists for conservation activitiesX
Use of alternative resources, such as utilization of water for electricity, wood for fuel, etc.
X
Waste management, reduce the use of materials that can not be recycled such as plastics,
cans, and aluminum that pollute the environmentEngage in ecological revitalization treatment
Cultural Preservation Efforts
Presentation of local arts and cultural attractions
Δ
Sale of handicrafts or souvenirs with local nuances
Δ
Local Communities Involvement and Welfare Improvement Efforts
Engaging local communities in the planning and development process regionEngagement of people who work in tourist sites
Involvement of the community as an entrepreneur or manager of accommodation services,Δ
attractions, transportation, and other supporting services
Involvement of the community as a marketing force, promotion and tour guideX
The community is given an opportunity by the owner to obtain education and training ofXtourism area management
 = currently applying, Δ = currently applying it halfway, X = currently not applying.

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38

Begonia (TBB)


X
X


X







IJERD – International Journal of Environmental and Rural Development (2019) 10-2

CONCLUSION
Although there are still efforts that are still in the planning stage, OFC has implemented quite
several efforts to carry out the value of the ecotourism concept. Meanwhile, TBB tourist sites, eventhough the land owned is relatively small and its starting from a hobby, this site applies a lot of thevalue of ecotourism concept. These indicate excellent attention from the managers of tourist sites,
although it is possible that the execution still found many shortcomings and constraints.
For some points that still cannot be applied, here are some suggestions to be considered. The
presentation of local arts and cultural attractions is still not implemented due to certain conditions.
The presentation can be applied by holding an art show on a small scale, maximizing the available
area (e.g., restaurant area), and making the show a monthly routine as a start. The introduction of aplan “one man one tree” can pursue financial assistance from the tourist for conservation activities.
The movement is to purchase one tree and plant it in an area that allows planters to see the trees
they have planted in the future (planted as decoration in the village open space, as well as on thestreets as the identity of ecotourism in Lembang, North Bandung).
It is unfortunate for a massive ecotourism site like the OFC that it still does not apply the
involvement of the community as a marketing force and allow obtaining education and training of
tourism area management. The reason is most likely due to the relatively new operation of the site,
but it would be much better if this were immediately applied. Because it does not rule out, theprepared concept cannot be carried out entirely due to the lack of coordination with the community
and the site manager. This effort can minimize errors and shortages of labor when human resources
are needed when doing an entertainment project related to nature tourism.
The need for control from the government and the involvement of local citizens in realizing
ecotourism will not only avoid unsustainable land use utilization. Ecotourism site connoisseurs arealso expected to have an awareness of problems that may arise from the addition of tourist
locations. Without eliminating the recreational side, ecotourism visitors are also expected to be
more sensitive to the conditions surrounding the ecotourism area as a positive influence of visiting
nature-based tourism. Hopefully, by this, we can also protect environmental conditions that are
currently being used by residents for other purposes such as agriculture and animal husbandry. On
a grander scale, it also can protect the water catchment area and prevent flooding in Bandung city.
This study provides a small picture of ecotourism that developed in the North Bandung area. A
review with more objects of study is certainly needed to be able to describe the more generalconditions of ecotourism, and arising environmental impact as the result of ecotourism development.
REFERENCES
Butarbutar, R., Soemarno. 2013. Environmental effect of ecotourism in Indonesia. Journal of IndonesianTourism and Development Studies, l. 1, 3, Retrieved from https://jitode.ub.ac.id/index.php/jitode/article/view/116 (in Indonesian).
ILO. 2012. Strategic plan sustainable tourism and green tourism for Indonesia. International Labour
Organization, Jakarta, Indonesia.
Izawa, T. 2010. Ecotourism in Bali: Backgrounds, present conditions and challenges. Journal of Ritsumeikan
Social Sciences and Humanities. 2, 73-103. Retrieved from http://www.ritsumei.ac.jp/acd/re/k-rsc/hss/book/pdf/vol02_07.pdf
JICA. n.d. Basic concept of 5S principles. Japan International Cooperation Agency, Japan. Retrieved fromhttps://www.jica.go.jp/activities/issues/health/5S-KAIZEN-TQM-02/ku57pq00001pi3y4-att/5s_Principle.
pdf
Masri, R.M. 2009. The study of environmental change in the bad zone for residential (Case study in northBandung Area), Bogor Agricultural University, Bogor, Retrieved from https://repository.ipb.ac.id/handle/123456789/40647 (in Indonesian).
Nirwandar, S. 2015. Ecotourism in Indonesia. Ministry of Tourism and Creative Economy, Jakarta, Retrieved
from https://sustainabledevelopment.un.org/content/documents/4488Nirvandar.pdf (in Indonesian).
Yanuarti, K.D. and Rosyidie. 2008. Study of Capolaga area development as attractiveness of eco-tourism.
Jurnal Perencanaan Wilayah dan Kota. Bandung Institute of Technology, Bandung, 19 (2), 23-36.
Retrieved from http://journals.itb.ac.id/index.php/jpwk/article/view/4201 (in Indonesian).
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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

Research article
erd

Performance Analysis of 325 kW Solar PV Rooftop System
Using PVsyst Program
PAKAYKAEW BOOTTARAJA
Faculty of Science and Engineering, Kasetsart University, Chalermphrakiat Sakonnakhon
Province Campus, Sakonnakhon, Thailand

NAPAPORN PHUANGPORNPITAK*
Faculty of Science and Engineering, Kasetsart University, Chalermphrakiat Sakonnakhon
Province Campus, Sakonnakhon, Thailand
Email: napaporn.ph@ku.ac.th
Received 19 December 2018

Accepted 15 August 2019(*Corresponding Author)

Abstract The power demand of electricity growing very fast with high concern of climatechange and environmental constrains. According to the Thailand Power Development Plan
2015 (PDP 2015) starting from 2015 to 2036, the national target of 30% of renewableenergy to total energy consumption by 2036 is to be achieved. Solar photovoltaic (PV) is
an important option makes the PDP 2015 meets the target. This paper aims to present theperformance analysis of the solar PV rooftop system installed at Sakon Nakhon Rajabhat
University. The system consisted of 1,016 polycrystalline silicon PV modules coupled to
13 units of 25 kW grid tied inverter. This system will be installed at the rooftop of the threebuildings namely, the Central Building (CB), the Engineering Technology Building (ETB)
and the Multipurpose Building (MB). The PV rooftop system is designed using PVsyst
program. The PV modules faced tilts and azimuths with 5°/31°, 10°/31° and 5°/16°,
respectively. The simulation results indicated that solar PV rooftop system can produce
452.92 MWh/year. The solar PV rooftop system could produce electricity generating from06.00 - 18.00. The performance ratio of the system is 0.74. The Central Building has
maximum power electricity generating as 44.44%. The Engineering Technology Building
has high performance ratio because of its tilts and azimuths of solar panels that affect theirradiation. The solar PV rooftop can reduce the peak demand in time 06.00-18.00 of
13.24% and the reduction of greenhouse gas emissions is 263.65 tco2/year.
Keywords climate change, photovoltaic, PVsyst (PV system design program), renewableenergy, solar PV rooftop system, sustainable development

INTRODUCTION
Solar photovoltaic (PV) is now widely used for power generation worldwide. According to theAlternative Energy Development Plan (AEDP 2015-2036), the renewable energy is targeted for
30% of total energy consumption in Thailand. Due to its cost competitive and high potential ofsolar energy in the country, solar power has been promoted and scheduled to be installed at 6,000
MW by 2036 (Tanatvanit, 2003 and Chimres, 2016). Sakon Nakhon Rajabhat University (SNRU)
is an academic institute in Sakonnakhon province which located in the northeastern part ofThailand. Sakon Nakhon Rajabhat University has an area of 1.02 km² and there are 50 buildings.
This institute has high energy consumption. The electricity cost per year is 20 million baht. Theenergy block grant project subsidized from the Ministry of Energy is launched in 2018 for the 325
kW solar PV rooftop to promote the use of renewable energy in the institute.

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

OBJECTIVE
This work was aimed to present the performance analysis of the 325 kW solar PV rooftop. The
PVsyst program was employed as a tool to investigate the technical performance assessment,
project design and its simulation. The three proposed buildings will be launched in 2020. This
study would be useful to predict the performance of the system, financial analysis and the user
perspective on a solar PV rooftop system. The study clearly illustrates the potential to use the PV
rooftop system to supply basic energy services that is desired in academic building settings.
MATERIALS AND METHODS
The installation of solar PV rooftop system at the Central Building (CB), the Engineering
Technology Building (ETB) and the Multipurpose Building (MB) is shown in Fig. 1.

Fig. 1 Research site
Figure 2 shows layout of the solar PV rooftop system. The solar PV rooftop system consists ofthe following components:Polycrystalline silicon PV 320 Wp (1,016 modules)
Grid tied inverter 25 kWac (13 units)
Monitoring system
Cable wiringFig. 2 Layout of solar PV rooftop systemⒸ ISERD

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

PVsyst Program
The PVsyst program is one of the energy modeling tools. It can show the useful results of solar PV
system including the produced power and the occurred losses in the system (Mermoud, 2014 andBoughamrane, 2016). The location site, setting tilt and azimuth, PV module and inverter
specifications are the required information for the program as shown in Fig. 3.

Fig. 3 PVsyst program
Technical Performance Assessment
The parameters for performance analysis of solar PV rooftop system followed by IEC 61724 areshown in Table 1 (Kumar, 2017 and Gurupira, 2017). The following nine parameters are used toanalyze the performance of the system: the reference yield (Yr), the array yield (Ya), the final yield(Yf), the array capture losses (LC), the system losses (LS), the performance ratio (PR), the arrayefficiency (ηa), the system efficiency (ηsys) and the capacity utilization factor (CUF) (Kumar, 2017
and Yadav, 2018).
Table 1 Equation for technical performance assessment
Parameter
Yr
Ya
Yf
LC
LS
PR
ηa
ηsys
CUF

Equation
Ht/Go
EDC/Po
EAC/PoYr - Ya
Ya - Y f
Yf/ Yr
EDC/(Aa Ht) x 100
EAC/(Aa Ht) x 100
EAC/(Po24365)x100

Unit
kWh/kWp/day
kWh/kWp/day
kWh/kWp/day
kWh/kWp/day
kWh/kWp/day%%%

Ht = Total irradiance at the standard test condition (kWh/m2/day)
Go = Global irradiance at the standard test condition (kWh/m2/day)
EDC = DC energy of the PV system (kWh)EAC = AC energy of the PV system (kWh)Po = Nominal power of the PV array at the standard test condition (kW p)
Aa = Array area (m2)

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Project Design and Simulation
Table 2 shows the description of PV system installation in three buildings: CB, ETB and MB. The
Central Building has the maximum roof areas for PV installation, followed by the Multipurpose
Building and the Engineering Technology Building.
Table 2 Description of PV rooftop system
Description
Location
Structure building
Roof area
Tilt/Azimuth
PV modules (320Wp)
PV modules area
No. of PV modules (set 1)

CB
17.18° N, 104.08° E
Metal sheet
1,643.35 m2
5°/31°
454 modules
888 m2
series=18modules
parallel=21 strings
series =19 modules
parallel=4 strings
6 unit145.28 kWp

No. of PV modules (set 2)
Grid-tied inverter (25 kW)
Total PV power

ETB
17.18° N, 104.08° E
Metal sheet
924.42 m2
10°/31°220 modules
430 m2
series =18 modules
parallel=8 strings
series =19 modules
parallel=4 strings
3 unit70.40 kWpMB17.18° N, 104.08° E
Metal sheet
1,323.60 m2
5°/16°
342 modules
669 m2
series =18 modules
parallel=19 strings

4 unit109.44 kWp

RESULTS AND DISCUSSION
Table 3 depicts the monthly average energy injected into grid, global incident, greenhouse gas
emissions and performance ratio. Among three buildings, the Engineering Technology Building
has slightly high performance ratio than other buildings as 0.743 because of its tilts and azimuths ofsolar panels that affect the irradiation.
Table 3 Monthly average energy inject to grid
Month
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Year

E-grid
(MWh)
17.94
16.00
18.22
17.79
17.72
16.82
16.26
15.43
14.30
17.04
16.35
17.44
201.30CB
Global(kWh/m2)
163.5
147.0
170.1
167.3
166.9
156.5
151.8
143.5
132.8
158.4
150.4
159.1
1867.4CO2(tco2)
10.44
9.31
10.61
10.36
10.31
9.79
9.46
8.98
8.32
9.92
9.52
10.15
117.18

PR
0.755
0.749
0.737
0.732
0.731
0.740
0.737
0.740
0.741
0.740
0.748
0.754
0.742

E-grid
(MWh)
9.114
7.992
8.967
8.591
8.435
7.996
7.745
7.413
6.968
8.440
8.263
8.926
98.848ETB
Global(kWh/m2)
171.3
151.4
172.6
166.6
163.9
153.4
149.1
142.1
133.4
161.8
156.7
167.8
1890.2CO2(tco2)
5.31
4.65
5.22
5.00
4.91
4.65
4.51
4.32
4.06
4.91
4.81
5.20
57.54

PR
0.756
0.750
0.738
0.732
0.731
0.740
0.738
0.741
0.742
0.741
0.749
0.756
0.743

E-grid
(MWh)
13.62
12.10
13.75
13.42
13.35
12.65
12.25
11.63
10.80
12.88
12.38
13.24
152.07

MB
Global(kWh/m2)
164.7
147.6
170.3
167.5
166.9
156.3
151.7
143.6
133.1
158.9
151.1
160.3
1872.0CO2(tco2)
7.93
7.04
8.00
7.81
7.77
7.36
7.13
6.77
6.29
7.50
7.21
7.71
88.52

PR
0.756
0.749
0.737
0.732
0.731
0.740
0.738
0.740
0.742
0.741
0.748
0.755
0.742

Table 4 shows the results of overall system, it depicts monthly average energy injected into
grid, global incident, greenhouse gas emissions, performance ratio, energy saving analysis andeconomics. The solar PV rooftop can reduce power consumption by 452.92 MWh/year.
Figure 4 shows the normalized PV production, i.e. the collection losses (LC) is 1.23
kWh/kWp/day, the system losses (LS) is 0.09 kWh/kWp/day and the produced useful energy (Yf) is
3.82 kWh/kWp/day. Figure 5 presents the performance ratio of the overall system for each month.
The highest performance ratio is 0.76 in January and December. The lowest performance ratio is0.73 in May. The performance ratio is slightly different in each month with the average
performance ratio of the system is 0.74.
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Table 4 Results analysis of the 325 kW solar PV rooftop systemMonthE-grid
(MWh)

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Year

40.73
36.15
41.00
39.87
39.56
37.52
36.31
34.53
32.12
38.42
37.05
39.67
452.92

Solar PV rooftop 325 kW
GlobalCO2(kWh/m2)(tco2)
165.6
148.1
170.7
167.2
166.2
155.8
151.2
143.2
133.0
159.3
152.0
161.4
1873.9

23.71
21.04
23.87
23.21
23.03
21.84
21.14
20.10
18.70
22.36
21.57
23.09
263.65

PR

Energy demand
06.00 – 18.00
24 hr
(MWh)
(MWh)

0.75
0.75
0.74
0.73
0.73
0.74
0.74
0.74
0.74
0.74
0.75
0.75
0.74

241.07210.79323.89295.75289.59274.01
326.00361.17379.70308.30229.92180.253,420.44437.08329.45463.39427.83418.68397.10459.04475.79540.59451.72352.73298.53
5,051.92

Energy conservation
Save
Save
06.00 – 18.00 24 hr
(%)
(%)
16.90
9.32
17.15
10.97
12.66
8.85
13.48
9.32
13.66
9.45
13.69
9.45
11.14
7.91
9.56
7.26
8.46
5.94
12.46
8.51
16.11
10.50
22.01
13.29
13.24
8.96

*** Emission factor = 0.58, Average electricity cost of SNRU = 4.39 Bath/kWh

Fig. 4 Normalized PV production

Fig. 5 Performance ratio

Fig. 6 Loss diagramⒸ ISERD

44

Economic(Bath)
178,804.70
158,698.50
179,990.00
175,029.30
173,668.40
164,712.80
159,400.90
151,586.70
141,006.80
168,663.80
162,649.50
174,151.30
1,988,362.70

IJERD – International Journal of Environmental and Rural Development (2019) 10-2

Figure 6 presents the loss diagram of the system. The array nominal energy at standard test
condition (STC) is 570.5 MWh, the array virtual energy at maximum power point (MPP) is 463.7
MWh. The available energy at the inverter output after the inverter loss was extracted would be theenergy injected into the grid is 452.9 MWh. The produced electricity from the solar rooftop systemdecreases during May to September due to the rainy season in Thailand.
CONCLUSION
The solar PV rooftop system is designed using PVsyst program as a tool. The system is planned to
be installed on the roofs of three buildings: the Central Building, the Engineering Technology
Building and the Multipurpose Building at the academic institute which located in the northeasternpart of Thailand. The Central Building can generated maximum power electricity of 201.30
MWh/year or 44.44% of the total system. The electricity produced during the sun rises (06.0018.00). The solar PV rooftop system can reduce the peak demand of electricity as 452.92
MWh/year or 13.24%/year during daytime (06.00-18.00). The generated electricity from solar PV
energy can reduce the use of electricity by 8.96%/year. The system can save electricity costthroughout the year as 1.98 million baht/year and the reduction of greenhouse gas emissions isequaled to 263.65 tCO2/year.
ACKNOWLEDGEMENTS
The authors are thankful to Sakon Nakhon Rajabhat University for project information support.
REFERENCES
Boughamrane, L., Boulaid, M., Tihane, A., Sdaq, A., Bouabid, K. and Ihlal, A. 2016. Comparative analysis ofmeasured and simulated performance of the Moroccan First MV Grid Connected Photovoltaic Power Plant
of Assa, Southern Morocco. Journal of Materials and Environmental Science, 7 (12), 4682-4691.
Chimres, N. and Wongwises, S. 2016. Critical review of the current status of solar energy in Thailand, 58,
198-207.
Gurupira, T. and Rix, A. 2017. PV simulation software comparisons: PVsyst, NREL (SAM) and PVlib,
SAUPEC.
Kumar, N.M., Kumar, M., Rejoice, R.P. and Mathew, M. 2017. Performance analysis of 100kWp gridconnected Si-poly photovoltaic system using PVsyst simulation tool. Energy Procedia, 117, 180-189.
Mermoud, A. and Wittmer, B. 2014. PVSYST user's manual.
Tanatvanit, S., Limmeechokchai, B. and Chungpaibulpatana, S. 2003. Sustainable energy development
strategies, Implications of energy demand management and renewable energy in Thailand. Renewable
and Sustainable Energy Reviews, 7 (5), 367-395.
Vasanthkumar, D.S. and Naganagouda, D.H. 2017. Design and development of 5MW solar PV gridconnected power plant using PVSYST. IRJET.
Yadav, S.K. and Bajpai, U. 2018. Performance evaluation of a rooftop solar photovoltaic power plant innorthern India. Energy for Sustainable Development, 43, 130-138.

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Research article
erd

Erosion Control and Slope Stabilization for Loose Sandy
Soil by Using Vetiver GrassPIYANUCH JAIKAEW*
Faculty of Science and Engineering, Kasetsart University, Chalerm Prakiat
Sakhon Nakhon Province Campus, Thailand
Email: piyanuch.jai@ku.th

KONGRAT NOKKAEW
Faculty of Engineering, Nakhonphanom University, Thailand
Received 5 January 2019

Accepted 15 August 2019(*Corresponding Author)

Abstract The root of vetiver grass has been proven to be effective to decrease erosion andincrease slope stability for soil slope. The important role of vetiver grass roots in preventing
water erosion and mass movement has been well recognized. However, quantitative
researches that present the contribution of vetiver grass to erosion control and slope stability
are limited, especially in the field study. This article presents the use of vetiver grass toslope erosion control and the role of vetiver root strength on slope stabilization for loose
sandy soil slope which is located at north eastern part of Thailand. The erosion wasmeasured in the field and then compared with the prediction from the Universal Soil Loss
Equation (USLE) proposed by the USDA Agricultural Research Service. The soil layer andproperties were investigated by borehole drilling and Kunzelstab penetration test, whichshown the slope was built with loose sandy soil. The root tensile strength of vetivers wastested in the laboratory by using direct tension test. As the diameter of root increase, theshear strength of roots decreases as a function of exponential. The slope stability of slope
stabilized with vetiver and without vetiver was analyzed using Infinite slope method. Slopewith vetiver has significantly higher factor of safety when compared to slope in bare soil.
Keywords slope stability, erosion control, vetiver, root stabilization

INTRODUCTION
Vegetation is usually used as an effectively protective layer for erosion control and slope stability
reinforcement throughout both hydrological process and improving mechanical soil properties. The
vegetation affects hydrological balance directly through evapotranspiration, water inception,
infiltration, and surface crushing (Morgan and Rickson, 1995). Typically, vegetation roots cananchor the soft layer soil mass into stronger layer and cross zones of weakness to more stable soil.
Roots system in the soil mass also provide tensile strength which contribute to improve the shear
load resistance of soil.
Vetiver grass (Chrysopogon zizanioides) has been widely used in many tropical countries for
erosion control and slope stabilization (Hengchaovanich, 1998). As vetiver grass is planted parallelto the slope contour with dense fine vertical deep root (3-4 m), it is effective for nailing soil mass
within slope and reducing soil erosion from runoff. In addition, vetiver grass has high tensile
strength of roots and high root distribution (Root Area Ratio), which contributes root reinforcement
and increase slope stability. Other benefit of using vetiver grass in slope are there is its low-cost,tolerance, and self-repairing ability. As a result, it is popularly used for slope protection in tropicalarea for both natural slope or man-made slope.
OBJECTIVEⒸ ISERD

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

The studies described the engineering of combination root system and result from the field. In thisstudy, the effect of root diameter on the tensile strength of roots was established.
METHODOLOGY
Erosion Control and Slope Stabilization with Soil-Bioengineering
1. Erosion Prediction using Universal Soil Loss Equation (USLE)The Universal Soil Loss Equation (USLE) is a semiempirical equation developed by the USDA
Agricultural Service in the early 1960s. The USE equation is formally used for predicting theerosion losses is crop land or agricultural activity, and then the equation was developed forconstruction activity such as slope highway, natural slope, and construction site. based on statisticalresults measured from the field. The USLE considers factors which cover climate, soil, topography,
and vegetation cover (Gray and Sotir, 1996). The soil loss from a site is predicted according to therelationship:
𝐴 = 𝑅. 𝐾. 𝐿𝑆. 𝐶. 𝑃

(1)where A = is predicted soil loss (ton/ km2 /year), R = is rainfall factor, K = is soil erodibility value,
LS = is slope length factor, C = is vegetation factor, and P = is erosion control in practice factor.
The detail procedure and USLE parameter estimation can be seen in many researches e.g.
Gray and Leiser (1982), Goldman and Bursztynsk (1986). However, on this paper the USLE
Parameters will be applied according to Apiniti (2557).
As this paper focus mainly in the soil parameters, so the effect of soil type on measured
erosion will be discuss extensively. The soil type is play important role on erodibility. The factors
including gradation, plasticity indices, soil structure, and void ration can affect the soil erodibility
value. A recommended hierarchy based on the Unified Soil classification system is presented as:
Most Erodible

Least Erodible

ML > SM > SC > MH > OL >> CL > CH > GM > SW > GP > GW
when GW = is well graded gravel, GP = is poorly grade gravel, GM = is silty gravel, SW = is wellgraded sand, SC = is clayey sand, ML = is low plasticity silt, MH = is high plasticity silt, CL = is
low plasticity clay, CH = is high plasticity clay, OL = is low plasticity organic soil.
2. Slope Stability with Vetiver Stabilization
The effect of vegetation on slope stability can be described as mechanical effects. Normally, soil
has high compression but rather low tension. The roots of vetiver are strong tension with weakcompression. Therefore, a combination of soil and vetiver roots can provide strength for thecomposite material (Thorne, 1990, Jotisankasa et al. 2015). Typically, the contribution of the
Vetiver root on shear strength of soil can be described in term of soil cohesion due to root
reinforcement, cr . Many researchers proposed the equation to estimate the root cohesion. However,
the root cohesion proposed by Wu et al. (1979) which describes the cohesion which considers theroot tensile strength, area density and root distortion angle as:𝐴

𝑐𝑟 = 𝑇𝑟 ( 𝐴𝑟 ) (𝑠𝑖𝑛𝜃 + 𝑐𝑜𝑠𝜃𝑡𝑎𝑛∅)(2)Ⓒ ISERD

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

where cr = is roots cohesion (kPa), Tr = is root tensile strength (kPa), Ar/A = is root-area ratio
surface (consider at shear surface,  is angle of distortion(degrees), and Ø is friction angle of soil
(degrees).
Normally, slope or embankment in semi-tropical or tropical area may experience theunsaturated equation. The shear strength of soil which combined the effect of unsaturated soil androot reinforcement can be express as (3)𝜏 = 𝑐𝑟 + 𝑐 ′ + 𝜎𝑛 𝑡𝑎𝑛∅′ − 𝑢𝑤 𝑡𝑎𝑛∅′′(3)where 𝑐 ′ = effective cohesion, 𝜎𝑛 = normal stress, ∅′ = effective angle, 𝑢𝑤 = pore water pressure,∅′′ = friction angle due to pore water pressure or matric suction which equal ∅′ when soil issaturated (𝑢𝑤 = 0).
The root cohesion and pore water pressure can be taken accounted in the slope stability
equation for infinite slope proposed by Fredland and Raharjo (1993), which can be expressed as:
𝑐 +𝑐 ′ +(𝛾𝑧𝑐𝑜𝑠2 𝛽)𝑡𝑎𝑛∅′ −𝑢𝑤 𝑡𝑎𝑛∅′′

𝐹= 𝑟

(4)

𝛾𝑧𝑠𝑖𝑛𝛽𝑐𝑜𝑠𝛽where 𝐹 = factor of safety, 𝛽 = slope angle, z = depth of failure plane, 𝛾 = soil unit weight. The
mainly impacted of Vetiver root on factor of safety are to reinforce the soil mass and to reduce thepore water pressure 𝑢𝑤 . The water table tend to decrease due to evaporation. If the pore waterpressure decreases to negative, the tension in water will be generate. Then, shearing strength of soil
will be increase significantly.
3. Site Investigation and Geotechnical Properties
To evaluate effect of Vetiver on erosion control and slope stability, the detention basin located in
Kalasin Province the north eastern part of Thailand was be chosen as a study site. The detention
basin is a large excavation project with total area 395 acres, and more than 10 km long for theboundary. The aerial photo of the detention basin was depicted as shown in the Fig. 1. The main
objective of the project is to store the water from the flooding season and to store the water for thecrops nearby the detention basin during the planting season 6.8 million cubic meter (At normal
storage +132 Mean-sea average). A cross section for slope excavation is presented in Fig. 2. The
total height of the slope is 8 m with slope 2:1 (horizontal: vertical, 26.6 o). The berm at 3 m wasdesign for spawning fish, and counter weigh the toe slope.

Fig. 1 Aerial photo of detention basin boundary

Fig. 2 Cross section for slope excavationⒸ ISERD

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

3.1 Soil Profile and Geotechical Properties along the Detention Basin
The soil profile and geotechnical properties of soil was investigated by the borehole drilling withwash boring machine. The five boreholes including BH-1, BH-2 BH-3, BH-4, and BH-5 were drill
along the slope of the detention basin and soil sample were collected for laboratory testing. The
cross section of the soil profile is shown in Fig. 3. It is found that at the depth 0 m to10 m the soil
layer for this area is non-uniform comprising with various fine soils such as low plasticity clay(CL), Low Plasticity Silt (ML), Low plasticity silt and low plasticity clay (CL). This maybe thisarea is located at the flooding plane. A highly weathered siltstone or mudstone which is a parent
rock was found after 10 m at the BH-1 and BH-5. After 18 m, the dense to very dense sand (SM)was mostly found lay uniformly with depth. The relationship of standard penetration test (SPT)with depth for all boreholes were shown in the picture. At near surface (<5 m) the SPT is lower
than 10, indicating of weak soil layer. The soil data from the borehole drilling will be used forslope stability analysis.

Fig. 3 Soil profile and the standard penetration value (SPT)from borehole BH-1, BH-2, BH-3 and BH-4
3.2 Soil Investigation and Sampling and at Near Surface along the Detention Basin
Since one of the objectives is to characterize the erosion of soil slope, the 15 soil samples which isused as representatives of soil along the detention basin were collected and test in the laboratory.
100

S1
S2
S3
S4
S5
S6
S7
S8
S9
S10
S11
S12
S13
S14
S15

Percent Finer (%)

90
80
70
60
50
40
30
20
10
0
10

Fig. 4 Boundary of the detention basin
and location for soil sampling

1 Diameter (mm) 0.1

Fig. 5 Grain size distribution of tested
specimensⒸ ISERD

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

Figure 4 presents the boundary of detention basin and location for soil sampling. The tests
included grain size distribution, percent of and, percent of fines particle, plasticity indices,
coefficient of uniformity (Cu), and coefficient of concavity (Cc) were determined for classifying
soil type according to the Unified Soil Classification System (USCS). Fig. 5 present grain size
distribution of all test samples. It is found that most samples comprising sand (particle between
0.075 mm to 4.75 mm) and tend to have uniform grade with size particles between 1mm to 3 mm.
The percent of fines varies between 2.4% to 53.0%. For Atterbergs’ limits, ten of fifteen samples
are non-plasticity soil, and five samples present a low plasticity soil. Classified by soil the USCS
most of soil are SP-SM while the rest are SM, SC, SP, and ML, respectively.
3.3 Soil Strength Investigation using Kunzelstab Penetration Test (KPT)The Kunzelstab Penetration Test (KPT) is one of the in-situ strength test which popularly usedbecause the test device is light weight, rapid to test, and economical to test when compare to otherfield test such as wash boring drilling or rotary drilling (Künzel, 1936; Krasaeteep and Thongchart,2012). The Kunzelstab device comprises guild rod with diameter 25 mm, sounding rod withdiameter 20 mm, hammer, anvil, base plate, penetration control, and cone with varying apex angle(60o, 90o, and 180o) (Kererat, 2016). During the test, the 10 kgs hammer will be raised for 50 cm inheight, and then drop freely, which equivalent 49 J (kg m2 s-2)/blow. The test will continue until theadvance distance of rod reach 20 cm. Then number of blows will be recorded (blows/20 cm). After
that, the bow count will be converse to strength parameter such as cohesion or friction angle.
Relationship between standard penetration test (SPT), Kunzelstab test (KPT), friction angle (Ø),
and relative density for sand is shown in Table 1.
Table 1 Relationship between standard penetration test (SPT), Kunzelstab test (KPT),
friction angle (Ø), and relative density for sand (EGAT 1980)
SPT(blows/30 cm)
0–4
4 – 10
10 – 30
30 – 50>50

KPT(blows/20 cm)
0–6
6 – 1818 – 55
55 – 92> 92

Ø(degree)25 – 30
27 – 32
30 – 35
35 – 40
38 - 45

Relative density
very loose
loose
mediumdensevery dense

RESULTS AND DISCUSSION
Erosion Prediction and Measurement
After the end of construction when the monsoon season pass, hundreds of erosions due to runoff
water were observed along the slope. Many types of erosion including sheet erosion, rill erosion,
gully erosion, until slope failure were observed along the slope of the project. The degree ofseverity for observed erosions can be ranked into four categories from level I low erosion, level II
medium erosion, level III severe erosion, and level IV extremely severe erosion. The erosion level I
represent non-erosion to rill erosion deep less than 5 cm. The level II erosion is rill erosion deep
from 5cm to 10 cm. The level III erosion is the deep rill or gully deep more than 10 cm. The level
IV erosion represents severe gully erosion with high volume soil mass. Fig. 6 presents erosion foreach level observed from the detention basin project. As the slope is 10 km long with varying typesof soil, the three zones were classified according by the soil type into zone A, zone B, and zone C
as shown in Fig. 4. For Zone A, the typically soil is reddish silty sand which is highly decomposedfrom the weathered mudstone, a parent rock which lay underneath in this area. Zone B is theuniform loose sand (SM), and zone C is mainly low plasticity clay with sand (SC).
In this study, the erosion parameters required for the USLE were summarized based on
Jotisankasa (2014). The Rainfall factor (R) was received from the rainfall station No 1110 HuasithonⒸ ISERD

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reservoir Kasasin Province (about 40 kms from the project). The soil erodibility (K) is depending on
the soil types. As the slope geometry is similar along the slope distance (10 m in length and 26.6o forslope angle), the slope length factor (LS) is the same value for zone A, Zone B, and Zone C.
Vegetation factor (C) is equal 1.0 for uncovered soil, and equal 0.1 for slope covering with Vetiver.
Erosion control in practice factor (P). As a result, the soil loss predicted from the USLE was 2,517.3
ton/hectare, 2,591.2 ton/hectare, and 1,258.7 ton/ hectare. The detail of parameters is shown in Table2.

a) level I: low erosionb) level II: medium erosionc) level III: severe erosiond) level IV: extremely severe erosion

Fig 6. Erosion level observed from the detention basin projecta) level I low erosion (erosion deep less than 5 cm) , b) level II medium erosion,c) level III severe erosion (rill to gully erosion deep more than 10 cm, andd) level IV extremely severe erosion deep gully

Table 2 Summary erosion parameters for soil loss prediction in case of without vetiver
convers
Erosion Factor
Rainfall Factor (R, mm/yr)
Soil erodibility value (K)Slope Length Factor (LS,m)Vegetation Factor (C)Erosion control in practice factor (P)Soil Loss (tons/hectare/year)

Zone A
583.53
0.34
9.76
1.0
1.3
2,517.3

Zone B
583.53
0.35
9.76
1.0
1.3
2591.2

Zone C583.53
0.17
9.76
1.0
1.3
1,258.7

Slope Stability Analysis with Rotation Failure
For deep slope failure, the slope stability for studied point were analyzed based on rotation method
using Simplified Janbu (1973), Simplified Bishop (1955), and Spencer (1973) Method. The shear
strength parameters used for analysis were obtained from Kunzelstab test. The possible worse
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set at 131 m mean-sea level. The KU Slope, a software developed by Kasetsart University, wasused to calculate the factor of safety. The example of slope stability analysis at KPT-3 andcompared to the slope failure which happen in the field the factor of safety for KPT-1, KPT-2,
KPT-3, and KPT-4 calculated using various method were shown in Table 3. It is shown that thefactor of safety ranges between 0.64 to1.60. The three analysis methods provide almost similar
factor of safety. Typically, for permanent slope the Factor of safety should lower than 1.5, thus thefour slopes at selected location have high risk to fail. The results from the analysis corresponds
well with result in the field because after the end of rainy season all four selected locations failed
with high soil mass movement.
Table 3 Factor of Safety calculated from Simplified Janbu, Simpliflied Bishop, and Spencer
MethodFactor of Safety
Location
KPT-1
KPT-2
KPT-3
KPT-4

Simplified Janbu

Simplified Bishop

1.23
0.64
1.56
0.81

1.24
0.69
1.53
0.88

Spencer
1.25
0.72
1.60
0.94

Factor of Safety for Infinite Slope Reinforced with Vetiver Grass RootIn order to evaluate the effect of Vetiver grass root on infinite slope stability using equation (4), A
scenario of soil slope and properties were set. In this analysis the root cohesion was calculated
based on equation (2). The tensile strength is predicted from the pullout test with equation (5) when
the root diameter equal was fixed at 1 mm. The unit weigh of soil is 1.8 t/m2. The failure plane
assumed to occur at 2 m. The pore water pressure (Uw) was assumed to be zero. Table 4 presents
the factor of safety at varying percent of root area (Ar/A) which is calculated from equation (4).
The factor of safety of bare soil (Ar/A = 0%) were 1.04, 1.02, 1.74, and 1.06 for Slope at KPT-1,
KPT-2, KPT-3, and KPT-4, respectively, indicating high risk to fail (Factor of Safety <1.5). The
factor of safety significantly increases with percent of root area ratio. With root area 0.2%, thefactor of safety can increase more than 5 times due to root reinforcement. This result shows strong
impact of Vetiver root on infinite slope, and it implies that slope will not fail in case of infinite
slope if there is a Vetiver grass root ratio more than 0.2%.
Table 4 The factor of safety of infinite slope with varying percent root area (Ar/A)
Location
KPT-1
KPT-2
KPT-3
KPT-4

Factor of Safety at varying percent of root area (Ar/A)
0%
0.2%
0.4%
0.6%
1.04
5.20
9.36
13.51
1.02
5.18
9.33
13.49
1.74
5.90
10.05
14.21
1.06
5.21
9.37
13.53

CONCLUSION
This paper presents the ability of Vetiver grass for reducing erosions and stabilizing the soil slopewith sandy soil. The detention basin project located at Kalasin Province, Thailand were selected
because the project had plant Vetiver grass along the slope to relieve the erosions and slope failuresin the project. The Vetiver roots were prepared and tested to obtain the tensile strength. It was
found that the slope covering with Vetiver grass can reduce soil loss from erosion ten times thanslope without Vetiver grass when computed with the Universal Soil Loss Equation (USLE).
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The Kuzelstab is an effective tool for finding the strength parameters. The Factor of safetycalculate from Simplified Janbu, Simplified Bishop, and Spencer were not significantly different.
For pullout test, the vetiver roots provide high tensile strength ranging between 10 MPa to 50 Mpa.
The tensile strength of Vetiver reduces with diameter as an exponential function. The Vetiver roots
significantly contributes the soil slope stability for infinite slope. With roots area ratio 0.2% thefactor of safety will increase five times.
ACKNOWLEDGEMENT
This work was financial supported from the Research and Development Institue, Kasetsart
University, Chalermprakiat Sakhon Nakhon Campus and The Royal Imitative Discovery
Foundation, the Royal Initiative Discovery Institute. In addition, the authors would like toacknowledge Department of Civil and Environmental Engineering, Kasetsart University Chalerm
Phakiat Sakhon Nakhon Campus and Program of Civil Engineering for providing test equipment
and time support for preparing the article.
REFERENCES
Bishop, A.W. 1955. The use of the slip circle in the stability analysis of slope. Geotechnique, 5 (1), 7-17.
Electricity Generating Authority of Thailand (EGAT). 1980. Soil exploration by Kunzelstab penetration test.
EGAT (in Thai).
Fredlund, D.G. and Rahardjo, H. 1993. Soil mechanics of unsaturated soils. John Wiley & Sons, New York.
Goldman, S.J.K. and Bursztynsky, T.A. 1986, Erosion and sediment control handbook. McGraw-Hill, NewYork.
Gray, D.H. and Leiser, A.T., 1982. Biotechnical slope protection and erosion control. Van Nostrand Reinhole,
New york.
Gray, D.H. and Sotir, R.B. 1996. Biotechnical and soil bioengineering slope stabilization: A practical guidefor erosion control. John Wiley & Son, Incs, USA.
Hengchaovanich, D. 1998. Vetiver grass for slope stabilization and erosion control, With particular reference
to engineering applications. Technical Bulletin No. 1998/2, Pacific Rim Vetiver Network, Office of theRoyal Development Project Board, Bangkok, Thailand.
Israelson, E. 1980. Erosion control during highway construction, Manual on principles and practices,
Transportation Research Program, Report No. 221, NAS-NRC, Transportation research board,
Washington DC.
Janbu, N. 1973. Slope stability computations in embankment-dam engineering. Hirschfled, R.C. and Polos,
S.J. (Eds.), Willey, 47-86. New York.
Jotisankasa, A., 2014. Soil-Bioengineering: Use of vegetation and soil engineering for erosion control andslope stabilization, Pre-One Part. Ltd, 264.
Jotisankasa, A., Sirirattanachat, T., Rattana, Rattana-Areekul, C., Mahannopkul, K. and Sopharat, J. 2015.
Engineering characterization of vetiver system for shallow slope stabilization. In the 6th International
Conference of Vetiver (ICV-6), 5-8 May 2015, Danang, Vietnam.
Kererat, C. 2016. Bearing capacity investigation of silty sandy soil layer using Kunzelstab test. JAES, 16 (1),57-61.
Krasaeteep, A. and Thongchart, S. 2012. A comparison of cone tip in Kunzelstab penetration test (KPT) In
17th National Convention on Civil Engineering, Udonthani, Thailand.
Künzel, E. 1936. Der Prüfstab, ein einfaches Mittel zur Bodenprüfung (The Test Rod, a simple tool for soil
testing). Zehn lehrreiche Beispiele der Bodenprüfung - 15 Möglichkeiten weiterer Anwendung. Bauwelt
No. 14, 327-329.
Machao, L., Holanda, F.S.R., Silva, V.S., Maranduba, A.I.A. and Lino, J.B. 2015. Contribution of the rootsystem of vetiver grass towards slope stabilization of the São Francisco River. Seminar: Ciências
Agrárias, Londrina, 36 (4), 2453-2464.
Mickovski, S.B. and van Beek, L.P.H. 2009. Root morphology and effects on soil reinforcement and slope
stability of young vetiver (Vetveria zizanioides) plants grown in semi-arid climate, Plant Soil, 324, 43-56.
Spencer, E. 1973. Thrust line criterion in embankment stability analysis. Geotechnique. 23, 85-100.
Styczen, M.E. and Morgan, R.P.C. 1995. Engineering properties of vegetation. Slope Stabilization and
Erosion Control, A Bioengineering Approach, Morgan, R.P.C and Chapman, R.R.J. (Eds.).
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Research article
erdComparative Study on 3 Rice Farming Systems:
Conventional, Partially Organic, and Organic Farming,
Case Study in Prey Kabbas District, Takeo, Cambodia
SEREIROTH BUNTHAN*
Graduate School of Agriculture, Tokyo University of Agriculture, Japan
Email: bunthan.sereiroth@yahoo.com

YAMADA RYUICHI
Faculty of International Agriculture and Food Studies,Tokyo University of Agriculture, Japan
Received 15 December 2018

Accepted 15 August 2019(*Corresponding Author)

Abstract Sustainable agriculture is an integrated farming system of plant and animal
production practices with site-specific applications that can maintain over the long term. It
is both environmentally sustainable and also can generate several impacts on rural society.
Unfortunately, the development of sustainable farming in Cambodia is still limited, and inits early stages. Despite sustainably farming has the potential for targeting niche markets
and ensure higher incomes, it is reported that the number of farmers choose to do or revert
to produce conventional rice farming instead. The application of chemicals in conventional
agriculture can generate high productivity; however, the intensive use of the chemical has
led to the destruction of soil and water resources. By observing these matters, this study
aims to examine the differences in characteristics and profitability between 3 farming
systems: conventional, partially organic, and organic rice farming, and to identify impacts
from sustainable farming to rice farmers. The present study is based on the survey
conducted in Prey Kabbas District, Takeo province, in 2018. In this study, a random
sampling method was applied, and 75 rice farmers were interviewed. Among the samples,
30 farmers practiced conventional rice farming, and others 45 farmers practiced sustainable
rice farming (25 adopted partially organic, and 20 farmers adopted organic rice farming).
The findings showed that despite the production costs of organic rice farming is higher,organic farmers still ensure higher yield and generate better profit. Both of sustainable rice
farming systems also found to benefit farmers with both social and human impacts.
Nevertheless, there are some constraints inhered these rice farming in this study area, suchas labor shortage, lack of organic materials, and market instability. There are needs forfarmers, supported institutes, consumers to work together to promote organic rice farmingin the study area.
Keywords conventional rice, organic rice, partially organic rice, profitability, Cambodia

INTRODUCTION
Food is crucial to human life. The rapid growth of populations, which in turn entails increased
demand for food, has led to changes in agricultural systems. With respect to Cambodian agriculture,
more Cambodian farmers are in the midst of transition from traditional subsistent to modern
commercial ones (Slayton et al., 2015). Modern agriculture systems have been practiced in many
countries, including Cambodia, with the aim of poverty alleviation, food security, and increasing
competitiveness. Although conventional agriculture has many large-scale positive effects, such as
high yields in crops and increases food supply through the adoption of new technologies. The
intensive use of chemical and mechanization has led to the destruction of the soil and water
resources. It has damaged the critical supporting ecosystems (OECD, 2001).

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Cambodia is one of the countries in Southeast Asia that is profoundly affected by the impactsof climate change, from the enormous floods in 2011 to the prolonged droughts in 2016.
Cambodian farmers have been increasingly exposed to the adverse effects of climate-related risks,both in terms of crop growth and pest and disease outbreak. It is recommended by Slayton et al.
(2015) to strengthen sustainable agriculture for future agriculture growth in Cambodia. However,there is still much work that needs to be done in promoting sustainable agricultural practices toCambodian farmers. Improper and excessive use of fertilizer is still one of the major agriculturalissues in the country. Farmers apply pesticides that are often not safe or counterfeit. Aside frombeing an unnecessary expense, this also results in an opposite outcome, which is the reinforcementof pest outbreaks by increasing pest resistance.
OBJECTIVES
The objective of this study is to grasp the differences in characteristics and economic performancesof 3 farming systems in the study area: conventional, partially organic, and organic farming, and to
identify the impacts of sustainable agriculture toward farmers in Prey Kabbas District, Takeo,
Cambodia.
METHODOLOGY
The study was conducted in Prey Kabbas District, Takeo province. This province classified as oneof the most significant rice-producing areas in Cambodia. Eighty-three percent of the population is
engaged in this sector. However, this research site is regarded as low diversification in farming
systems, and it is easy to prone to a natural disaster such as drought and flood every year. With
such a poor farming condition, farmers in the research site have gradually shifted towardsustainable farming with the help from the government and Non-Profit Organization (Prey Kabbas
district report, 2014).
This study is based mostly on primary data collected through direct interviewing with rice
farmers in the district. Interviewed farmers were selected by random sampling method. The survey
was conducted from August to September 2018 (20 days). Totally 75 rice farmers were interviewed
and categorized into three groups: group A (conventional farmers- 30 respondents) and a group of
farmers who practiced sustainably adopted rice farming: group B (partially organic farmers- 25
respondents) and group C (organic farmers- 20 respondents). The partially organic farmers refer toa group of farmers who used at least 50 percent of organic material in rice farming, and organic
farmers refer to a group of farmers who applied only organic material in rice farming.
RESULTS AND DISCUSSION
Socio-Economic Characteristics of Studied Farmers
Table 1 Socio-economic characteristics of sustainable and conventional rice farmers

Source: Field survey in 2018
*Indicates statistical significance at 0.05 levelⒸ ISERD

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The basic features of interviewed farmers are presented in Table 1. Table 1 showed that farmers ofgroups B and C had more extended education compare to farmers in group A, although it is not
significantly different. This indicated that education encourages farmers to adopt a new farming
system while considering the environment and agricultural production in the long term. However,concerning family size and owned and planted areas, there was no significant difference among
these 3 group farmers.
Total Production Cost of Rice Farming
Table 2 Total production cost of three farming systems

Source: Field survey in 2018
*Indicates statistical significance at 0.05 level

Unit: USD/ha

It found that in the study areas, there were three different types of rice farming existed and that thesystems differed much in the input use among them. Thus, in the analysis of costs and returns ofrice farming, diversified aspects among three farming systems should be full took into account.
Concerning the cost analysis, this study followed the method of Slayton et al. (2015). The
study calculated the cost not only of cash payment, but also imputed costs such as cost of organic
fertilizer, family labor costs, cost of owned land, and depreciation of farm assets. To check thesignificance of differences in cost items between farming systems, T-test with two-sampledassuming unequaled variances is applied in this study as well.
As shown in Table 2, the total production cost of organic farming per ha was higher thanconventional and partially organic farming in the study area. Cost comprised both cash and noncash costs, based on the result of the survey; cash costs were the ones that directly affected thefarmers’ financial conditions. High cash costs could disrupt farm production activities and put
farmers in debt. Although the overall total costs of organic rice were higher, it is also clearly shownthat organic rice farming initially entailed similar cash costs to the conventional and partiallyorganic rice farming in the study area.
Economic Returns of Rice Farming
Regarding economic returns, several indicators, such as gross margin, total cash income, and net
profit of each rice farming type, are examined in this study. Gross margin obtained by deducting
gross revenue, intermediate inputs, and hired labor. Total cash income calculated by subtracting
total cash expenses from gross revenue. Finally, net profit calculated by deducting costs of familyⒸ ISERD

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labor, costs of owned land, and depreciation cost from gross margin. In addition, T-test analysis
with two-sampled assuming unequal variances was applied in this study as well.
Table 3 showed the comparison of cost and returns per hectare among conventional andsustainable rice farming in the study area. The production of organic rice was significantly more
profitable than conventional rice farming in terms of gross margin and total cash income. However,when total net profit was analyzed, the result showed conventional, partially organic, and organic
rice farming was not significantly different. This indicated that whatever model used that excluded
non-cash cost, organic farming in the study area was the most profitable. It is understandable sinceorganic farming in the study area obtained higher yield and premium price compare to conventional
and partially organic rice. Although partially organic rice practiced in consideration of environmentand health purposes, however, the average price of partially organic rice was not significantly
different from conventional rice, which resulted in less profitable than organic rice farming.
As mentioned earlier, whenever non-cash expense considered in this study, organic rice was
not significantly the most profitable one among groups. In general, most organic rice farmers usedtheir on-farm resources to do organic farming; however, in this specific study area, farmers tended
to purchase lots of animal manure from farmers from other villages. Higher organic fertilizer andfamily labor costs resulted in less total net profit in comparison to conventional and partiallyorganic farming. This result also realized the reason behind the concerns of farmers to continue
producing the organic products in the study area.
Table 3 Net profit of three farming systems

Source: Field survey in 2018
*Indicates statistical significance at 0.05 level

Unit: USD/ha

Impacts and Constraints of Sustainable Rice Farming
Understanding the considerable differences in costs and returns between conventional andsustainable rice farming in the study area, it is also necessary to examine the impacts andconstraints from adopting these farming systems to farmers. The distribution of respondents’opinions and benefits they received is explained mainly in the descriptive analysis.
Social Impact
Farmer group participation: Based on the survey, it was seen that only 30 percent of
conventional farmers were able to participate in farmer groups since most of them were seen to
engage in some other off-farm works heavily. On the other hand, organic and partially organic
farmers were instead more focus on on-farm work. They found to have some additional spare time
to join and participate more enthusiastically in farmer group activities. Some of their hard worksⒸ ISERD

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were already recognized and able to generate profit, such as selling their own made livestock feeds,organic rice wine, seeds, and fertilizers to both inside and outside the village. Participation infarmer group activities is not only providing them financial benefits to farmers, but things such aslabor sharing, farming information, idea sharing, updating marketing news, and possible sources offunds are provided while joining the group as well.
Relationship establishment: Two kinds of relationships were found: (i) direct relationship and (ii)indirect relationship. With respect to the direct relationship, the connection within the farmers’
families is observed. From the survey, within conventional farmers, men mainly took care of mostof all the farming work, while women took care of small activities such as seeding, weeding, andpost-harvest tasks. Most children and women found to engage more in off-farm jobs. For farmers
who practiced sustainable farming, on the other hand, spouses found to work mainly on farmland,and due to the additional labor required, children and wives also took a big part in farming
activities as well. This suggesting that a closer family relationship of organic farmers is observed
during their work, which also instills agricultural loyalty in the children.
The Indirect relationship between farmers who practice sustainable farming and consumer
also existed. Farmers gather together once a month and share their monthly results, update
marketing news from dealers, and sharing new sustainable farming knowledge and information.
This type of relationship plays a crucial role in strengthening the promotion of organic agriculturein the study area, considering external factors, such as consumer demand, influence thedevelopment of agricultural systems.
Human Impact
Knowledge development on sustainable farming: Based on the survey, organic farmers obtained
their knowledge of sustainable farming techniques and skills through joining agricultural
cooperatives. Certain developments, however, have been adopted by organic farmers through aprocess of combing local culture and recent findings, to respond to the requirements of agricultural
production and environmental conditions. Tables 4 and 5 showed the result estimation of multiple
comparison tests between conventional and partially organic farmers regarding their awareness ofsustainable farming knowledge. The result implied that partially organic farmers are significantly
aware of organic farming and some local knowledge related to a safe way to use agrochemical
products.
Table 5 Level of awareness of safety
use of agrochemical

Table 4 Level of awareness of organic
farming technique

Constraints on Organic Rice Farming
The constraints of organic farming in the study can classify into five categories: (i) lack of organic
material, (ii) labor shortage, (iii) long growing period, (iv) low yield, and (v) market instability. As
illustrated in Fig. 1, farmers believed that the labor shortage was the main reason that hinders themfrom adopting organic farming. This is understandable since organic farming spent more time ontransplanting and weed management activity, which resulted in higher numbers of labors. In
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has already existed in the study area. Lack of organic material was also mentioned as theconstraints since most of the farmers in the study are aging, and they found it hard to find or collectthe organic materials around their village. As mentioned, farmers tended to purchase lots of animal
manure from other farmers even though the price of the animal manure was much higher comparedto the inorganic fertilizer.
The long growing period and market instability were concerned by studied farmers as well.
They noted that organic farming had a more prolonged production stage, which hindered themfrom producing rice more than once in a year. Furthermore, most conventional farmers were notmembers of any organic farmer group, so it was hard for them to find a market for organic productswith the premium price.

Fig. 1 Farmers’ perception of constraints
toward organic rice farming
Source: Field survey in 2018

CONCLUSION
The result of the analysis of production costs and returns revealed that cost indicators, such as grossmargin and total cash income, reported that organic farming received higher income and more
profitable from the economic viewpoint in comparison to conventional and partially organic
farming. Moreover, sustainable farming systems such as partially organic and organic also
benefited farmers in the study area to establish relationships within their family, among farmers
and consumers, aware of the endangerment of agrochemical products to society and environment,
and provide the opportunity to share and discuss knowledge and information. Unfortunately,
constraints such as labor shortage and lack of organic material had hinder farmers from adopting
sustainable farming in the study area. To respond to these matters, two significant issues are neededto address in order to improve the organic farming in the study area: (i) providing detailed training
programs more widely especially to young farmers, and (ii) introducing farmers to the integrated
farming system to help them minimize production cost, improve quality and quantity of soil andfood produced, and increase cash income.
REFERENCES
Angelantonio, D.A., Fabio, M., Francesco, M. and Michele, M. 2005. Social aspect of organic farming. 4th
ENAOS Summer Meeting, Pomeranian, Poland.
Arpaphan, P. and Ganesh, P.S. 2009. Opportunities and constraints of organic agriculture in Chiang Mai
Province, Thailand. J. Asia-pacific Development, 161, 115-147.
Department of Agriculture, Prey Kabbas District. 2012-2017. Annual agricultural report of Prey Kabbas
district, Takeo, Cambodia.
Jitsanuan, T. 2001. Development of sustainable agriculture. Paper presented at the policy meeting of Ministryof Agricultural and Cooperatives, Office of Agricultural Economics, Bangkok.
Organization for Economic Co-operation and Development. 2001. Adoption of technologies for sustainable
farming systems. Report Commissioned by OECD.
Provincial Department of Agriculture. 2012-2016. Annual Agricultural Report, Takeo Province, Cambodia.
Rada, K., Teuraki, N. and Yosuke, C. 2016. Profit efficiency of rice farmers in Cambodia, The differencesⒸ ISERD

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between organic and conventional farming. J. Sustainable Development, 96, 1913-9063.
Slayton, T., Mudita, C. and Munichan, K. 2015. Cambodian agriculture in transition: Opportunity and risks.
Report Commissioned by the World Bank and AusAID.

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Research article
erdPhysical and Chemical Properties of Compost Made from
Agricultural Wastes
THIDAR KHAING*
University of Mandalay, Mandalay, Myanmar
Email: thidarkhaing7878@gmail.com

SUU SUU WIN
Sagaing Univeristy of Education, Sagaing, Myanmar

NYO NYO WIN
Myitkyina University, Myitkyina, Myanmar
Received 15 December 2018

Accepted 15 August 2019(*Corresponding Author)

Abstract Compost is a decomposed organic material that can be used to help grow plants
and keep soil healthy. The main objectives of this research are to prepare compost fromagricultural wastes and study the physical and chemical properties of agricultural wastes
and prepared compost. These agricultural wastes are cow dung, rice husk, saw dust, sesamehusk and chaff. The physical and chemical properties of agricultural wastes and compost
were characterized by pH, moisture, organic matter, calcium, magnesium, sulphur, nitrogen,phosphorus, and potassium. The EM (effective microorganism) solution was prepared byusing organic kitchen wastes except onion and garlic peels for mixing in prepared compost.
The microscopic morphology of microorganism was also studies for EM solution. The
results showed that the prepared compost has pH value 7.29, moisture (20.39%), organic
matter (22.89%), calcium (1.96%), magnesium (0.61%), sulphur (0.07%), nitrogen (1.25%),
phosphorus (1.62%), potassium (1.56%), iron (1.30%), manganese (0.02%), copper(0.03%), zinc (0.01%) and chloride (1.07%). The yield percent of prepared compost was
found to (58.45%) based upon the amount of agricultural wastes. The physical and chemical
properties of agricultural wastes and prepared compost were used in soil management in agood way to improve and maintain soil quality, soil fertility, and conserve the environment.
Keywords agricultural wastes, physical and chemical properties, EM solution, compost

INTRODUCTION
Compost means to put together the correct amounts of compostable materials to make a great soil
amendment. It is the biological reduction of organic material to humus; it is made from residues ofplants and/or animals that are piled, moistened and allowed to decompose, and bacteria, insects andworms in the pile help this break down (Raabe, 2004). Quality control during compost production
should ensure adequate chemical and physical properties (Inbar et al., 1993), as well as an adequate
degree of stability and maturity (Benito et al., 2003). The beneficial effects on crop production andsoil quality reported in literature (Hoitink et al., 1997; Atiyeh et al., 2001) are related to thephysical, chemical, and biological properties of the composts (He et al., 1995). Agricultural wastes
are defined as the residues from the growing and processing of raw agricultural products such as
fruits, vegetables, meat, poultry, dairy products, and crops. They are the non-product outputs ofproduction and processing of agricultural products that may contain material that can benefit man
but whose economic values are less than the cost of collection, transportation, and processing for
beneficial use. Their composition will depend on the system and type of agricultural activities andthey can be in the form of liquids, slurries, or solids. Agricultural waste otherwise called agrowaste is comprised of animal waste (manure, animal carcasses), food processing waste (only 20%
of maize is canned and 80% is waste), crop waste (corn stalks, sugarcane bagasse, drops and culls
from fruits and vegetables, pruning) and hazardous and toxic agricultural waste (pesticides,Ⓒ ISERD

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insecticides and herbicides, etc). Estimates of agricultural waste arising are rare, but they are
generally thought of as contributing a significant proportion of the total waste matter in thedeveloped world (Agamuthu, 2009). Effective Microorganisms (EM) are mixed cultures ofbeneficial naturally occurring organisms that can be applied as inoculants to increase the microbial
diversity of soil ecosystem. They consist mainly of the photosynthesizing bacteria, lactic acidbacteria, yeasts, actinomycetes and fermenting fungi. These microorganisms are physiologicallycompatible with one another and can coexist in liquid culture. There is evidence that EM
inoculation to the soil can improve the quality of soil, plant growth and yield (Kengo and Hui-lian,2000).
Therefore, the present investigation was conducted to study produce a good quality compost
from agricultural wastes. The physical and chemical properties of the agricultural wastes andcompost were determined by the end of processing period. These properties include pH, moisture,organic matter, calcium, magnesium, sulphur, nitrogen, phosphorus, potassium, iron, manganese,copper, zinc and chloride.
METHODOLOGY
Sample collection: The agricultural waste materials such as cow dung, rice husk, saw dust, sesamehusk and chaff were collected for the preparation of compost in June 2018. Cow dung wascollected from Myitnge village and rice husk, saw dust, sesame husk and chaff were collected fromproduction of Industrial Zone (I), Pyingyitagon Townships, Mandalay Region, Myanmar. Cow
dung samples were dried under the sunlight for 3 months. The rice husk, saw dust, sesame husk andchaff were pounded and sieved with 60 sieve mesh size to get the size of powder.
Preparation of effective microorganism solution: The EM solution was prepared in container all
the wastes of the fruits and vegetables from the kitchen except onion and garlic peels were placedin a 10 liters container to ferment for one month. The fermentation time took about one month toobtain effective microorganism (EM) solution.
Preparation of aerobic digester: The plastic container (50.8 cm) was taken. One hole (2.54 cm indiameter) was made at the centre of the base of the container to seep the liquid of the decomposing
organic matter from container. Four holes were made around the top of the container, at 38.1 cm
from each other. Another four holes were made around the bottom third of the container, at 38.1 cm
from each other.
Preparation of compost by using aerobic method: Compost was prepared by mixing of cow
dung (0.25 kg), rice husk (0.25 kg), saw dust (0.25 kg), sesame husk (0.25 kg), chaff (0.25 kg) andEM (10 L) solution in container (50.8 cm).
Turning over for compost under aerobic condition: During decomposition, the waste products
were turned over regularly, in order that it remains well aerate and all the materials were converted
into compost. The first turning over was done after two weeks. The second turning overtook thatafter one week. Then, each turning over was done after one week. During the process, water was
sprinkled over the container, if necessary. After one month, decomposition was complete because
the waste materials were changed into an unrecognizable crumbly dark mass. However, somestalks do not decomposed completely and can still be seen.
Analysis of physical and chemical composition of agricultural wastes and compost: The
agricultural wastes and compost were air dried and physical and chemical properties were
determined based upon the total weight of selected materials used (FAO, 2008).
Determination of pH of agricultural wastes and compost: Cow dung (5 g), rice husk (5 g), saw
dust(5 g), sesame hush (5 g), chaff (5 g) and prepare compost (5 g) were weighed accurately andplaced into a each beaker and 100 mL of distilled water was added into each beaker (the ratio ofsample to water was 1:4). It was shaken and heated for 30 minutes. It was cooled and filtered. The
filtered was determined by digital pH meter.
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Determination of moisture contents of agricultural wastes and compost: With the oven-drying
method, the loss of water on heating agricultural wastes and compost at 105°C in a silica crucible
and heating it in a temperature control oven for 5 hours.
Determination of total sulphur contents of agricultural wastes and compost: 2-5 mL of aliquot
was taken into 50 mL volumetric flask. 5 mL of 50% acetic acid, 2 mL of 0.25% Gum Acacia and1 mL of ortho-phosphoric acid was added into the flask. It was shaken for 1 min. 0.2 g of BaCl 2
crystal was added and shaken for 1 min. Make the volume up to 50 mL with distilled water.
Measure the turbidity intensity at 440 nm.
Determination of total nitrogen by using Kjeldahl method: 0.5 g of each sample was put into
600 mL digestion tube and 1 g of catalyst was added. It was heated gently unit frothing ceases. The
flask was removed from the heater and cool, distilled water was added and transfer to the suitable
volumetric flask. Accurately 20-25 mL of 2% Boric Acid was placed in the receiving conical flask.
2-3 drops of methyl red indicator was added. Water was add enough to cover the end of thecondenser outlet tube. 5 mL of aliquot pipette into the distillation tube and 5 mL of 40% NaOH
was added and the ammonia was distilled for about 4 minutes. The receiving flask was removed
and rinsed the outlet tube into the receiving flask with a small amount of distilled water. Excessacid was titrated with 0.02 NH2SO4. Determine the blank a reagent in the same manner.
Determination of total phosphorus by using Molybivanado phosphoric acid method: Pipette
5-25 mL of aliquot depending on P content in a 50 mL volumetric flask and add 5 mL of Barton’s
Reagent and dilute to 50 mL with distilled water. After 1 hour, measure with spectrophotometer at
420 nm.
Determination of potassium, calcium and magnesium by using atomic absorption
spectroscopic method: Potassium, calcium and magnesium content of agricultural wastes andcompost were determined by Atomic Absorption Spectroscopic Method (AAS), at Department ofAgriculture (Land Use), Ministry of Agriculture and Irrigation, Mandalay.
Determination of organic matter in agricultural wastes and compost: Loss of weight on
ignition can be used as a direct measure of the Organic Matter (OM). The sample is ashed at 500600°C by placing a suitable weight (0.5-1.0 g) of the sample in a silica crucible and heating it in a
muffle furnace for 4-6 hours.
Determination of yield percent of compost: The compost was dried and the yield percent wasdetermined based upon the total weight of selected materials used.
Isolation of microorganism from EM solution by using sub-micrometer: Isolation of
microorganism from EM solution was done at Department of Biotechnology, Mandalay
Technology University (MTU). The microscopic morphology of microorganism was also studied
for EM solution (Krieg, 1984).
RESULTS AND DISCUSSION
Physical and Chemical Properties of Agricultural Wastes
Physical and chemical properties of agricultural wastes used for composting were measured. The
results are shown in Table 1. According to these results the pH value of rice husk is greater thanothers. The pH value is directly affects plant growth. Calcium, potassium and moisture werehighest values in cow dung. Sesame husk has highest phosphorus, sulphur, nitrogen amount andhigher organic matter. Nitrogen, phosphorus and potassium are essential minerals for agriculture.
The mixture of the richest sources, such as sesame husk, saw dust, chaff, cow dung and rice husk
were combined and made the compost which used for agriculture. The agricultural wastes improve
the overall health of soil and produce healthy various plants. The physical and chemical propertiesof prepared compost were rechecked in agricultural wastes and the results are described in Table 2.

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Table 1 Physical and chemical properties of agricultural wastes used for composting
Parameter

Sesame husk

Saw dust

Chaff

Cow dung

Rice husk

pH
Moisture (%)
Organic matter (%)
Total Ca (%)
Total Mg (%)
Total S (%)
Total N (%)
Total P (%)
Total K (%)

6.62
6.24
89.97
1.07
0.15
57.10
3.36
0.48
0.51

6.95
9.61
91.18
0.52
0.07
16.90
0.19
0.01
0.06

7.14
12.19
23.49
0.23
0.11
2.50
0.09
0.01
1.01

7.23
22.80
51.03
9.70
0.57
38.60
2.18
0.41
1.15

7.43
12.93
79.36
0.19
0.12
31.50
0.41
0.02
0.93

Table 2 Physical and chemical properties of compost
Parameter

Results
7.29
20.39
22.89
1.96
0.62
0.07
1.25
1.62
1.56
1.30
0.02
0.03
0.01
1.07

pH
Moisture (%)
Organic matter (%)
Total Ca (%)
Total Mg (%)
Total S (%)
Total N (%)
Total P (%)
Total K (%)
Total Fe (%)
Total Mn (%)
Total Cu (%)
Total Zn (%)
Total Cl (%)

In accordance with the comparisons of physical and chemical properties of crude wastes andprepared compost, sulphur and nitrogen content are significantly decreased in compost which may
be produced of gas in combination period. The organic matter is also reduced in prepared compost
which is decomposed of agricultural wastes, cow dung and EM solution in moist aerobic conditions.
Yield Percent of Compost
Yield percent of compost was obtained 58.45% on based upon the total weight of material inaerobic condition.
Table 3 Cultural and Microscopic Morphology of Isolated Bacteria
Colony Morphology
Sample Sizename (mm)
EM 1

2

EM 2

3

EM 3

2

Color
White
(Transparent)
White(Opaque)White(Transparent )Elevation

Shape

Flat

Irregular

RaisedIrregular

RaisedIrregularⒸ ISERD64

Microscopic Morphology
Size
Gram’
Shape
(µm) reaction
2-2.5×
Rod,
+
5-6
spore
1.5-2×
Rod,
+
3-4
spore
1-1.5×
Rod,
+
5-7
spore

FamilyBacillaceae

IJERD – International Journal of Environmental and Rural Development (2019) 10-2

The Isolation of Microorganism from EM Solution
The microorganisms were isolated from prepare effective microorganisms solution. Thesemicroorganisms were used accelerator on composting process. EM cultures have been usedeffectively to inoculate both farm wastes as well as hasten the treatment process. EM enhances soil
fertility and promotes grow ripening in crops. The isolated bacteria were shown in Table 3.

Fig. 1 Cultural and microscopic morphology of isolated bacteria
Three bacterial isolates (EM 1, EM 2, EM 3,) from sample EM were isolated on Nutrient
media. According to the cultural and microscopic morphology, all three bacterial isolates on
Bacillaceae shows in Fig. 1. Bacillaceae is mainly due to their ability to form resistant endospores.
It is believed to be the key factor determining the ecology of these bacteria. They also performfundamental roles in soil ecology and in plant health and growth stimulation.
CONCLUSION
According to physical and chemical properties of compost which should be used as organic
fertilizer. As a result of analysis data of prepared compost showed that suitable for plant growthand health. In addition, waste products and compost were observed to be suitable for agriculturalused. According to cultural and microscopic morphology, two aerobic bacterial strains wereobserved in liquid of EM solutions with different conditions. The compost should be used widely inagriculture because of their low cost, good fertility of the soil and supplying more trace elements. It
provides many essential nutrients for plant growth and therefore is often used as fertilizer.
Therefore, prepared compost has great potential for applications and as a source of plants nutrients.
ACKNOWLEDGEMENTS
We would like to acknowledge my sincere gratitude to Dr. Thida Win, Rector, University of
Mandalay for their permission to perform this research work. We particularly want to thank Dr. Yi
Yi Myint, Professor and Head, Department of Chemistry, University of Mandalay, for her
providing research facilities, guidance, and suggestions on my research work.
REFERENCES
Agamuthu, P. 2009. Challenges and opportunities in agro-waste management: An Asian perspective.
Inaugural Meeting of First Regional 3R Forum in Asia, 11-12 Nov., Tokyo, Japan.
Atiyeh, R.M., Edwards, C.A., Subler, S. and Metzger, J.D. 2001. Pig manure vermicompost as component of
a horticultural bedding plant medium: Effects on physicochemical properties and plant growth. Bioresour.
Technol., 78, 11-20.
Benito, M., Masaguer, A., Moliner, A., Arrigo, N. and Palma, R.M. 2003. Chemical and microbiologicalparameters for the characterization of stability and maturity of pruning waste compost. Biol. Fert. Soils,
37, 184-189.
FAO. 2008. Guide to laboratory establishment for plant nutrient analysis. Rome, Italy. 30-44.
He, X., Logan, T.J. and Traina, S.J. 1995. Physical and chemical characteristics of selected US municipal
solid waste composts. J. Environ. Qual., 24, 543-552.
Hoitink, H.A., Stone, A.G. and Han, D.Y. 1997. Suppression of plant diseases by composts. Hort Science, 32,
184-187.
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Inbar, Y., Chen, Y. and Hoitink, H.A. 1993. Properties for establishing standards for utilization of composts
in container media. In: Hoitink, H.A.J. and Keener, H.M. (Eds.), Science and Engineering ofComposting: Design, Environmental. Microbiological and Utilization Aspects. Ohio State University,
USA.
Kengo, Y. and Hui-lian, X. 2000. Properties and applications of an organic fertilizer inoculated with effective
microorganisms. Journal of Crop production, 3 (1), 255-268.
Krieg, N.R. and Holt, T.G. 1984. Bergey`s manual of systematic bacteriology. 1 st ed., 1, Williams andWilkins, Baltimore.
Raabe, R. 2004. The rapid composting method. Vegetable Research and Information Center. University ofCalifornia, USA.

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Research article
erd

Effect of Long-Term Rubber Tree Plantation on Soil
Properties Comparing to Sugarcane Plantationin Khon Kaen, Thailand
XAYSATITH SOULIYAVONGSA*
Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand
Email: xaysatith1@hotmail.com

VIDHAYA TRELO-GES
Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand

SUPAT ISARANGKOOL NA AYUTTHAYA
Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand

CHRISTIAN HARTMANN
Institute of Ecology and Environmental Sciences (iEES-Paris),
Institut de Recherche pour le Developpement, Bondy, France

ALAIN PIERRET
Institute of Ecology and Environmental Sciences (iEES-Paris),
Institut de Recherche pour le Developpement, Vientiane, Laos
Received 12 February 2019

Accepted 15 August 2019(*Corresponding Author)

Abstract Following extensive land conversion from other crops to rubber plantations,Southeast Asia has become the main natural rubber producer in the world. Within Southeast
Asia, Thailand is a leader of rubber production. This research addresses the question of thelong-term effect of land conversion to rubber tree plantations on selected soil properties.
The study reported here aimed to evaluate change in soil properties after 5 and 23 years of
rubber tree plantation (5 RB, 23 RB) compared to soil properties under annual cash crops
such as sugarcane (SG), in Kranuan district, Khon Kaen province, Thailand. Randomized
sampling was conducted at soil depth increments from 0-10 to 150-160 cm. Topsoil organiccarbon, total N and total K were higher in 23 RB than in the 5 RB and in the SG system.
Available phosphorus in 23 RB was also higher than in soil under the 5 RB system, but notsignificantly different from that in the SG system. Soil pH was identical throughout the soil
profile in the three observed cropping systems. We found evidence of soil compaction
under the SG system at the 30-40 cm depth. Finally, topsoil in 23 RB had higher moisture
content than that under the 5 RB and SG systems. Overall, this study indicated that, relative
to cash crops such as sugar cane, conversion to rubber tree plantation in Northeast Thailand
did not lead to land degradation and even improved some of the soil property indicators.
Keywords rubber tree plantation, soil quality, cash crops, soil degradation

INTRODUCTION
Rubber tree (Hevea brasiliensis) is an important economic tree in tropical areas. In 2015, Thailand
was the first world rubber producer with 4.5 million tons (Thailand Board of Investment, 2016). In
the past, Northeast Thailand was considered as a marginal area for rubber trees due to climaticconstraints. During the last 20 years, in relation with expected high benefits, farmers have
converted many of their annual cropland (sugar cane, cassava) to rubber plantations. The
environmental impact of this shift from annual to perennial crops remains unknown. Previous
intensive and continuous annual cash cropping has degraded sandy soils of the Northeasternplateau. In particular, deep and repeated tillage and lack of organic restitutions resulted inⒸ ISERD

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compaction of deeper layers (20-40 cm) and reduced soil organic matter levels to <1%. Suchdegradation is sometimes so severe that near-permanent erosion gullies occur even when the slope
is <5%. In rubber plantations as in many other perennial tree plantations, the absence of tillage andthe continuous accumulation of organic debris on the soil surface appears to facilitate a restorationof soil physical characteristics and an increase in soil organic matter. On the other hand, theabsence of fertilization in rubber plantations may result in chemical degradation, acidification and adecrease in mineral nutrients.
OBJECTIVES
The objective of our study was to compare selected physical and chemical properties of soil undersugar cane, young and old rubber plantations and assess the impact of the rubber plantations on
sandy soil already degraded by continuous annual cropping systems.
METHODOLOGY
Site Description
A study site representative of rubber tree plantations of Northeast Thailand was selected at KhamHai village, Kranuan district, 50 km north of Khon Kaen city. Parent material was alluvial sandstone and current altitude is around 250 m asl. Soil is Chum Puang series (Cpg) with coarse-loamy,
siliceous, isohyperthermic Typic Kandiustults; pH is ranging from 5.5 to 7 in the top soil and from
4.5 to 5 in subsoil and it is considered as a low fertility soil (LDD, 2015). The rubber tree
plantation was converted from fields where cassava and sugarcane alternated for several decades.
We compared 3 land uses: sugarcane (SG), 5 and 23 year old rubber tree plantation (5 RB and 23
RB, respectively). For each land use we sampled 3 replicates, i.e. blocks A, B, C. The blocks werelocated within a few hundred meters from each other (Fig. 1). As each plot was located at least 100
m from each other, we assumed that they were independent from each other, which allowed the useof ANOVA.
Block A

Block B

Block C

Fig. 1 The study plots in Khamhai village, Kranuan district, Khon Kaen, Thailand
=sugarcane plantation (SG), =5 years old rubber tree plantation (5RB),
=23 years old rubber tree plantation (23RB) in Blocks A, B, CⒸ ISERD

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Soil Sampling and Analysis
Rubber tree spacing was 2.5 x 7 m between trees and lines, respectively. Sugarcane spacing was
0.3 x 1.5 m between plant and lines. Samples were collected at 3 points per block, in which 3
points were randomized within the plot in the area of 50 x 50 m. At each point, samples werecollected at 6 different depths between the plant rows: 0-10, 10-20, 30-40, 60-70, 100-110 and 150160 cm (Haile et al., 2008, Gama-Rodrigues et al., 2010, and Monroe et al., 2016). The samples
were oven dried at 105°C for 48 hours to determine the water content; after that, samples weresieved with 2 mm mesh size and stored in sealed plastic bags for laboratory analysis. Soil pH was
measured in 1:2.5 soil: water suspensions with glass electrode pH meter. Organic Carbon (OC) was
determined using the Walkley and Black’s method, the total N was determined by Kjeldahl’s
method, while available phosphorus (P) was extracted by BrayII method. Exchangeable K wasdetermined by extraction with neutral 1M NH4OAC. Percentage of coarse sand, find sand wasdetermined by sieving.
Statistical Analysis
Data were tested for normality; standard deviations were computed and outliers identified. Data
were analysed by analysis of variance (ANOVA) as randomized complete block design (RCBD).
All computations were done with the R software, and the Tukey’s test was applied to identify
differences between means at 5% probability level. Microsoft Office Excel was used to plot figures.
RESULTS
Soil Physical Properties

Fig. 2 Soil physical properties of three studied plantations 23RB, 5RB and SG in
Khamhai village, Kranuan district, Khon Kaen, Thailand
Throughout the soil profile 0-160 cm depth, bars followed by different letters are
significantly different according to Tukey HSD test n= 24, α=0.05.
Horizontal solid lines correspond to the standard deviation

Sand content in this area was > 60% on the average. The analysis revealed that three study
plots were not significantly different throughout the soil profile. The high amount of sand content
was consistent with low fertility and low content of plant nutrients. Soil moisture content of thethree 23 RB plantations was higher (p<0.001) at 0-10 cm (0.13 g g-1), than that of 5 RB (0.11 g g-1)
and SG (0.08 g g-1) samples. In the 10-70 cm depth layers, there were no differences in soil
moisture content between the three cropping systems (Fig. 2). Between 70 and 160 cm depths,
however, soil moisture content was higher in the SG than in either the 23 RB and 5 RB systems(p<0.001). The bulk density of the 0-20 cm depths was not significantly different among systems.
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However, at soil depths of 30 to110 cm depth, bulk density was higher in the SG than 23 RB or 5
RB systems (Fig. 2). In the SG system, the highest compaction was found at 30-40 cm depth (1.81
g cm-3).
Soil Chemical Properties
The soil pH of the entire area was very low which is the case for sandy soils of this region ofThailand and for soils of this particular classification (Ultisols). We found that long term rubber
tree plantation did not appear to change the soil pH in the top 10 cm of soil depth compared to 5RB
and SG systems (p>0.29). However, the 10-20 cm layers of the SG system revealed a lower mean
pH (5.3) compared to that in 5 RB system (5.6) (p<0.01). The pH at depths between 30 and 110 cm
were not different for the 3 situations whereas a pattern similar to that observed at 10-20 cm, i.e. 5
RB > SG but 23 RB not different from either 5 RB or SG, was found at 110 and 160 cm depths(Fig. 2).

Fig. 3 Nutrient, Carbon content and pH of the three plantation systems
23 RB (23 years under rubber), 5RB (5 years under rubber) andSG (sugar cane system) in Khamhai village, Kranuan district,Khon Kaen, Thailand
Throughout the soil profile 0-160 cm depth, bars followed by different letters are
significantly different according to Tukey’s HSD test n= 24, α=0.05.
Horizontal solid linescorrespond to the standard deviation

Organic carbon was higher in the 23 RB system than in SG throughout the soil profile and also
different from 5 RB from the surface to 30 cm (Fig.2). OC of the 23 RB system was 2.75 and 4.58
times higher compared to 5 RB and SG systems, respectively. Total N in the studied area was also
very low, less than 0.05%on the average, even in the top soil of the 23 RB system (Fig. 3). The 23
RB was characterized by the highest total N at 10 cm, while 5 RB was highest at 20 cm depth.
There were no major differences between the 3 systems deeper in the profile. Levels of availableⒸ ISERD

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phosphorus of 23 RB, 5 RB and SG were also very low throughout the soil profile, again consistent
with the soil classification of (Ultisol). There were, however, significantly higher amounts of P in
the top10-20cm of SG. Finally, exchangeable K was higher in 23 RB than in the SG system fromthe surface down to 40 cm depth.
DISCUSSION
This study revealed that organic carbon levels increased slightly, but not significantly in the top soilof the 23-year-old rubber tree plantation compared to that in the 5-year-old rubber tree plantations
and sugar cane plantations. This low increase in OC might be due to the low input of litter in rubber
tree plantations compared to that occurring in natural forests. Naturally occurring tropical forest
structure typically comprises 4 layers; namely the emergent layer, the canopy, the understory andthe forest floor. Rubber tree plantations, however, only have the canopy layer with hardly any
growth on either the understory or the plantation floor (Spies, 1998). The four layers of rain forest
structures play an important role for ecosystem, especially soil protection and in improving soil
fertility. Soil fertility accumulation also depends on tree species (Ramesh et al., 2013), with somespecies producing more biomass than others and/or biomass that is more readily degradable oftencaused by differences in lignin/nitrogen ratio, C/N, and cellulose etc) . Sang et al. (2013) reported
that A. mangium plantations decreased soil bulk density and increased OC, total N and available P
compared to secondary forest and pasture. It has been reported that the litter fall of rubber tree
plantation is less than that of oil palm, jungle rubber and natural forest, amounting to an average of
only 3.84 Mg ha-1 while that of natural forest was 9.04 Mg ha-1. This clearly results in a lower
nutrient return to the soil (Kotowska et al., 2016). The total nitrogen in the top soil of 23 RB was
significantly higher compared to that of either the 5 RB or the SG systems, probably because ofhigher biomass accumulation. However, this increase in total N in 23 RB was, as in the case of OC,very small, probably due the large amounts of N needed for rubber tree growth or exported in latex
production. Indeed, Iewkittayakorn et al. (2018) reported that the N content of latex is of the orderof 40%. Finally, available P in the SG system was significantly higher than that in either the 23 RB
or 5RB system, most likely as the result of previous chemical fertilization.
The main result of the work presented here was that OC, total N and exchangeable K in old
rubber tree plantation were higher at some soil depths than in 5RB and SG systems. This is in linewith results of Lakshmi et al. (2016) who reported reductions of N and K in sugarcane monocropping. Long term sugarcane cultivation in semi-arid regions and soils can, reportedly, increase
OC and total N in 0-10 cm soil depth (Beza and Assen, 2016) which is not consistent with our
results. This outlines the need for further studies to clarify the respective effects of sugar cane andrubber tree on soil fertility depending on soil type and climate. In this study, we also report that the
BD of sugarcane plantation was very high, reaching 1.81 g cm-3 at the 40-70 cm depth, whichconstitutes a compacted layer. This reveals the negative impact of the use of heavy machinery to
manage crops on such sandy. weathered soils (Usaborisut, 2011; Barzegar et al., 2005). Soil
preparation is also a known a factor influencing SOC loss and soil degradation (Bilandžija et al.,2016). Together with improved OC levels at the surface in the 23 RB system, the higher soil
moisture content illustrates the widely reported positive effect of organic matter on water retention(Brady, 1990; Robin et al., 2018; Minasny and McBratney, 2018; Ankenbauer and Loheide, 2017).
Deeper in the soil however, our study indicates that soil moisture content was higher under thesugar cane system, which may reflect a lower water uptake than that of 23 and 5 year old rubber
tree plantations.
CONCLUSION
In the studied plots of Khon Kaen province, Northeastern Thailand, rubber tree plantations were
found to improve soil fertility, especially soil organic carbon as well as total N, and exchangeable
K in comparison with a sugar cane system. Available P in sugarcane plantation was higher than inrubber tree plantation most likely because of the effect of fertilization. In this specific agroⒸ ISERD71

IJERD – International Journal of Environmental and Rural Development (2019) 10-2

ecosystem, rubber tree plantations did not appear to have a negative impact on soil fertility relative
to previously established sugarcane crops. However, more extensive long-term studies should be
carried out to clarify the relevance of the results of this study.
REFERENCES
Ankenbauer, K.J. and Loheide, S.P. 2017. The effects of soil organic matter on soil water retention and plantwater use in a meadow of the Sierra Nevada, CA: Soil organic matter affects plant water use. Hydrol.
Process, 31, 891-901. https://doi.org/10.1002/hyp.11070
Barzegar, A.R., Sh. Mahmoodi, F. Hamedi. and Abdolvahabi, F. 2005. Long term sugarcane cultivation
effects on physical properties of fine textured soils. J. Agric. Sci. Technol., 7, 59-68.
Beza, S.A. and Assen, M.A. 2016. Soil carbon and nitrogen changes under a long period of sugarcane
monoculture in the semi-arid East African Rift Valley, Ethiopia. J. Arid Environ., 132, 34-41.
https://doi.org/10.1016/j.jaridenv.2016.04.005
Bilandžija, D., Zgorelec, Ž. and Kisić, I. 2016. Influence of tillage practices and crop type on soil CO2
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Limited effect of organic matter on soil water retention. Eur. J. Soil Sci., 69, 39-47.
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soil fertility and CO2 efflux under hilly ecosystems of Northeast India. Agrofor. Syst., 87, 1377-1388.
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types of exogenous organic carbon on soil organic matter and physical properties of a sandy technosol.
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investment location in the heart of southeast asia. Thail. Invest. Rev., 26, 12.
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Research article
erd

A Comparative Study of Economic Efficiency Between
Small and Medium Size Rubber Plantationin Thbong Khmom Province
KEOVORLEAK VICHET
Graduate School of Agriculture, Tokyo University of Agriculture, Japan
Email: keovorleakvichet@gmail.com

TOMOHIRO UCHIYAMA*
Faculty of International Agriculture and Food Studies, Tokyo University of Agriculture, Japan
Email: tu205722@nodai.ac.jp
Received 14 December 2018

Accepted 27 August 2019(*Corresponding Author)

Abstract The strong fluctuation of price makes investment decision difficult, especiallysmallholder rubber plantation that depend solely on rubber production to support theirlivelihood. An investment analysis of the rubber production was needed to complete thestudy, so a discounted cash flow (DCF) was introduced to account for this study. The
findings of the study illustrate that the investment of rubber seemingly economicallyfeasible. However, the result from the Discounted Cash Flow Analysis showed that the time
to recover the initial investment on the rubber plantation is getting longer at the current
price of rubber. The payback period will be 11.9 years for small size producers. For
medium size plantations, the payback period was estimated to be 12.2, 10.5 and 9.8 years in
MI, MII and MIII, respectively. The further findings also suggest that small size producers
have less choice in term of output produce that they want to put out in the market.
Keywords discounted cash flow analysis, natural rubber, payback period, profitability,
productivity, smallholder rubber plantation

INTRODUCTION
Rubber has long been a major commercial crop and export earner for Cambodia and, as a laborintensive crop, has the potential to contribute to poverty alleviation through rural employment. The
gross value added of rubber in 2006 was estimated at USD103.61 million, or about 5 percent ofagricultural sector production (MAFF, 2008).
The growing surplus of rubber worldwide, which is steadily decreasing the demand for
Cambodian rubber (Hor and Renzenbrink, 2013). According to a representative of Chop Rubber
Plantation, a major rubber exporter, the global oversupply of natural rubber reduced their prices
significantly from $3,100/ton to $2,100/ton in 2013 (Ross, 2016). Domestic demand for rubber isalso very low and studies have revealed that “there is currently very little domestic use insecondary or tertiary industries for Cambodia’s natural rubber products” (Ministry of Commerce,2013).
In 2014, 70% of the total rubber production was contributed by household-owned rubber
plantation. According to General Directorate of Rubber, the price of rubber has been decreased by
3/4 compared to a decade ago. However, little attention is given to their profit efficiency and its
determinants. Farmers’ income who live in the rural areas depends heavily on rubber production.
The instability of rubber price, and low productivity due to the lack of technology and information,
it affects greatly on their income.
OBJECTIVEⒸ ISERD73

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General objective of this study is to analyze economic efficiency of the rubber farmers. The
specific objectives are: 1) Identify the socio-economic characteristic of rubber producers, 2) Accessto farmer’s profitability, 3) Analyze the financial feasibility of rubber producers, and 4) Formulate
suggestions and recommendations.
METHODOLOGYDCF analysis was used as the framework for assessing the returns from the investment ofhousehold-owned rubber production, with the usual investment criteria of net present value (NPV),
internal rate of return (IRR), and benefit-cost ratio (BCR) (Campbell and Brown, 2003). A positive
value of NPV for a given project shows that the project’s benefits are greater than its costs. When
IRR is equal to or greater than the interest rate, the investment is worthwhile. If the value of BCR isequal to or greater than 1, it is a sign that investment is of worth, but if it is less than 1, theinvestment project is not profitable. In order to apply DCF, the costs and benefits of rubber
production first had to be identified, where the costs include establishment costs (before yielding
stage) and maintenance costs (after yielding stage). Then the issue of the discount rate had to beaddressed. Therefore, an allowance was made for risk and uncertainty through a sensitivity analysis.
RESULTS AND DISCUSSION
Farm Characteristics of the Small and Medium Size Rubber Producers
Table 1 Farm characteristics of the studied area

Average Rubber Owned Area (ha)Average Planted Tree (tree / ha)
Average Mature Tree (tree / ha)
Average Immature/Damaged Tree (% / ha)
Average Rubber Tree Age (Year)
Tapping Frequency (days / week)
Output Produces

S
Under 2(n=20)
1.3
557
456
17.3
8
2
Coagulum 1)MI
2 to 10(n=18)
4.4
559
472
15.7
9
6.6
Coagulum 1)

MII
10.1 to 20(n=14)
16.6
566
511
7.9
12.6
6.8
Latex 2)

Labor Type

Family labor

Family labor

Family labor +Seasonal
hiring labor

Items

MIII
20.1 up(n=11)
41.2
563
524
7.5
13
7
Latex 2)
Non-family
management 3)+
Fixed hiring
labor

Source: Field Survey, 2018
Notes:
1) Coagulum: Coagulated latex. There are two ways to coagulate latex, by additional acid to latex or let it coagulate
naturally. Due to high cost of acid S and MI producers in the studied area use the later method to coagulate their latex
and sell it as coagulum.
2) Latex: MII and MIII producers sell their produces in the liquid latex form. The price will be determined by the DRC(Dry Rubber Content) % that has in the latex and Dry Rubber Price at the farm gate.
3) Non-family management: No family labor is engaged to manage the plantation. 1 to 2 managers are hired to manage
the whole plantation in addition to the working labor (eg: tapping labor).

The farm characteristics is presented in Table1. Rubber producers were categorized into two maintypes, small (S) and medium (M) scale producers. For further investigation, this study divides
medium scale producers into three categories, accordingly. MI refers to medium scale producers
that use family labor only to manage the plantation, while M II are producers that manage theplantation themselves and use hired labor occasionally. Lastly, M III are producers that use hired
labor only to manage the plantation.

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For S producers refer to those who own less than 2 ha and use family labor only. As presented
in the Table 1, the average owned area is 1.3 ha, 4.4 ha, 16.6 ha, and 41.2 ha, respectively. There isno transition of land or rental land system found in the studied area. Most of the producers acquired
the land from the government, inheritance, and purchased land. The planting density is not so
different between the 4 groups of producers, as they planted an average of 550 to 560 per ha.
However, the ratio of immature/damaged tree is different across the groups, the producers that has
the most immature/damaged tree is S producers that accounted for 17.3% following by MI 15.7%,
MII 7.9%, and MIII 7.5%, respectively. This is the crucial point since only the mature area ofplantation is calculated and compared and number of tree per ha is statically significant related tothe productivity of the plantation itself.
Another distinguish differences that can be spotted in Table 1 is the age of rubber and tapping
frequency. Compare to the M producer’s groups S producers have smaller plantation area. Since
the rubber tree can be tapped every four days, producers with bigger plantation areas tapper canrotate the tree in circle and able to tap every day (Usually 400 trees can be tapped per day pertapper).
Profitability Analysis of Small and Medium Size Rubber Plantation in the Study Area
Total production cost:
The total production cost includes both variable and fixed cost. The variable costs include theexpenditure of fertilizers, herbicide control, latex stimulants and labor costs (tapping labor,
fertilizing labor, herbicide labor, and latex stimulant labor).
Table 2 Total production cost of rubber production

Table 1 Total Production Cost by Plantation Sizes
Items

Fertilizer
Herbicide Control
Latex Stimulation(2)
Family Labor(3)
Hiring Labora. Total Variable Cost
b. Total Fixed Costc. Total Production Cost (a+b = c)

S
Under
2 ha
(n=20)
513
170
187
3,321
0
4,191

MI
%
2 to
10 ha
(n=18)
11
544
4
178
4
193
74 3,220093 4,135

MII% 10.1 to20 ha(n=14)
12
642
4
195
4
214
72
929
2,139
93
4,119

378

7

371

7

355

4,514

100

4,450

100

4,425

Unit: riel/tree/year
MIII
%
20.1
ha up
(n=11)
15
677
4
213
5
223
21
0
48 2,988
93 4,102%

t-statistic

15
5
5
0
68
93

S vs MI S vs MII S vs MIII
2.03
2.03*
2.07*
2.12
2.06
2.09**
2.05
2.08
2.07
2.03 2.04***
N/A
N/A
N/A
N/A
2.08
2.03
2.04

330

7

2.04

2.03

2.05

100 4,405

100

2.04

2.05

2.04

7

Source: Field Survey, 2018
Notes: N/A = no data
1) The production cost does not include the cost that applied on the immature area of the plantation.
2) Current wages are applied to calculated family labor cost. (25,000 riel/day)3) There is no hiring labor cost in S and MI producers, only family labor is engaged in the plantation.
4) Establishment cost refers to all the expenses incurred during the first six years till the plantation come tocommercial yielding stage. Depreciation straight line method was used to calculate the annual share ofestablishment cost.
Significant codes: *** 0.001 **0.01 * 0.05

Fixed costs consist of establishment costs only, since there are no agricultural taxes in
Cambodia and all the interviewed producers owned the land they are farming. Moreover, unlike
other countries the interviewed producers only produce and sell raw material (coagulum, and latex),with no machines or heavy machinery involved in the rubber production. Establishment cost
includes all the expenses incurred during the first six years till the rubber tree comes to yielding
stage. The total cost of establishment comprised land preparation, lining and holding, planting,clone replacement, weeding, pruning/branch induction, fertilizer, and disease control.
To avoid being biased in this study, the total cost per tree has been computed. More than 70%of the total cost goes into labor for S producers. Producers in the studies area applied at least 1 bag(50 kg) of fertilizers (chemical) per ha to the rubber plantation and apply twice per year. One bagof fertilizer can cost up to 120,000 riel/bag (30 USD). The average quantity of fertilizer appliedⒸ ISERD

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was roughly 151 kg/ha, the cost of fertilizers wraps up 15% of the total variable costs, annually.
Usually, latex stimulant is applied once a month, with roughly about 1 liter/ha costing around
10,000 riel/liter.
Rubber productivity and profitability:
Two types of produce were in the market, coagulum and latex. Coagulum is coagulated latex andconsists of two ways to coagulate the latex. It can be developed by introducing additional acid tolatex or by simply allowing it coagulate naturally. Due to the high cost of acid, S and MI producers
in the studied areas use the latter method to coagulate their latex and sell them as coagulum.
Table 3 Average rubber productivity and profitability
Items
Yield (kg / tree) (a)Price (riel / kg) (b)A. Revenue (A = a*b)
Total Variable Cost (riel / tree) (c)Total Fixed Cost (riel / tree) (d)B. Total Production Cost (B = c+d)
C. Net Farm Income (A+B = C)S
Under 2 ha(n=20)
4.97
1,890(1)
9,395
4,191
378
4,514
4,881

MI
2 to 10 ha(n=18)
5.41
1,877(1)
10,161
4,135
371
4,450
5,711

MII
10.1 to 20 ha(n=14)
2.79
4,307(2)12,001
4,119
355
4,425
7,576

MIII
20.1 ha up(n=11)
2.87
4,345(2)12,477
4,102
330
4,405
8,072

Source: Field Survey, 2018
Notes:
1) Coagulum rubber price riel/kg2) Dry rubber price riel/kg
3) The production cost does not include the cost that applied on the immature area of the plantation.

Table 3 shows the average yield per tree for S and MI coagulum production, the producers’
yields equated to 4.97kg and 5.41kg, and the net farm income was computed at an average price of
1,890 riel/kg and 1,877 riel/kg. Net farm income per tree/year came in at a total of 4,881 riels and
5,711 riel for S and MI producers. The average yield per tree was 2.79 kg and 2.87 kg for latex
production, with the net farm income standing at 7,576 riel and 8,072 riel.
MII and MIII producers can generate more profit than S and MI producers, as latex is ahigher-grade rubber that is used to make elastic bands, teats for babies’ bottles, and athletic shoes,
while coagulum is a low-grade (quality) rubber that is used for tires (ADI, 2007). Most of the large
processors prefer to buy latex rather than coagulum and offer a premium for it. In contrast,
smallholders prefer to sell coagulum, as farmers can receive cash in hand (Hing and Thun, 2009),
where the smallholders producing the coagulum are selling them to collectors at either the farm
gate or at various collection points in the districts’ towns. Smallholders are also known toadulterate their latex with all kinds of additives, rendering it unusable for higher grades of rubber(ADI, 2007). Due to this, the factory prefers to make a deal with large-plantations so that they cansecure the quality as well as the quantity.
Rubber smallholders have little choice but to sell their collected latex to private companies forprocessing and export, given that only semi-processed (dry) rubber, not latex, can be exported(Hing and Thun, 2009). Competition among collectors is limited and localized, resulting in pricecollusions against the farmers (so farmers are quoted the same prices by the collector) (Rubber
Sector Profile, 2012).
Discounted Cash Flow Analysis
The financial feasibility analysis for rubber production was carried out by employing important
tools such as the Net Present Value, Benefit Cost Ratio, Internal Rate of Return, and Payback
Period as seen in Table 4.
The BCR for the rubber plantation presented more than unity in every category, but also
implied that rubber cultivation was a profitable venture. The Net Present Value of the stream ofⒸ ISERD

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returns from one hectare of rubber plantations worked out to 38,231,362 riel for S producers,
40,820,918 riel for MI, 43,311,209 riel for M II and 46,030,839 riel for MIII at a non-discounted
rate. The high positive Net Present Value indicates the soundness of the investment.
The internal rate of returns equated to 21% for S producers, however the ratio was 23%, 32%,
and 33% in MI, MII, and MIII respectively. Since the values of the internal rate of returns are
considerably higher than the market rate, more than 14.50% would be financially feasible(Shunmugiah, 2000).
Table 4 Benefit cost ratio and internal return rateIRR
NPVPB (Year)BC
Source: Field Survey, 2018

S

M1

M2

M3

21%
38,231,362
11.9
1.8

23%
40,820,918
12.2
1.8

32%
43,311,209
10.5
1.7

33%
46,030,839
9.8
1.8

The payback period refers to the time required to recover the initial investment in the rubber
production. While the payback period worked out to be 11.9 years for S producers, the payback
period for medium-size plantations was estimated to be 12.2, 10.5 and 9.8 years for MI, MII, andMIII, respectively. Thus, all the criteria of financial feasibility of the project indicated thatinvestment in rubber production was economically feasible and financially sound in the study areas.
Table 5 Results of DCF analysis for rubber producers
Table 4. Result of DCF analysis (Using world bank projected price and wage rate of 34,000riel/day)
5%
Scenario
S
MI
MII
MIII
S
A

B

C

NPV (riel/ha)
B.C ratio
IRR%
NPV (riel/ha)
B.C ratio
IRR%
NPV (riel/ha)
B.C ratio
IRR%-1,244,873-462,624-124,128 1,234,496
0.97
0.99
1.00
1.03
3.90%
4.60%
5.30%
7.40%
10,327,710 12,006,326 13,960,084 15,506,547
1.26
1.29
1.30
1.33
13.60%
15.10%
21.00%
22.00%
25,372,068 28,215,962 32,269,560 34,060,215
1.64
1.67
1.69
1.74
23.00%
24.80%
35.80%
36.50%-1,868,824
0.94
3.90%
5,352,964
1.17
13.60%
16,620,349
1.52
23.00%

8%MI

MII-1,015,001-130,399
0.97
1.00
4.60%
5.30%
6,757,139
9,051,105
1.20
1.24
15.10%
21.00%
18,952,529 23,115,069
1.56
1.61
24.80%
35.80%

MIII-678,883
1.02
7.40%
10,153,484
1.27
22.00%
24,376,616
1.65
36.50%

Source: Field Survey, 2018
Notes: A scenario: Rubber price decrease by 30% (of projected price); B scenarios: World Bank projected price;
C scenarios: Rubber price increase by 30% (of projected price).

Table 5 shows the DCF applied the sensitivity analysis of small and medium-sized rubber
plantations at the discount rate of 5% and 8%. Table 5 is using the wage of 34,000 riel/day tocompute.
The results show that for 30% less than the projected price (scenario A), the investment for
rubber production is unprofitable in all categories. With the world bank projected price (scenarioB), the investment shows positive signs in all categories, indicating that the investment project isviable. At 30% more than the projected price (scenario C), the investment was worthwhile for all
discounted rates.
The findings from the sensitivity analysis shows that if the input material costs were toincrease by 30% from the current price, the investment in rubber production would no longer beworthwhile, indicating that the expansion of rubber may stop if there is a decline in the price of
rubber in the future. In fact, at the wage rate of 34,000 riels/person per day and a discount rate of
5%, the investment in rubber production becomes unprofitable when the price of rubber decreases
more than 30% from the current market price. This could perhaps be countered by increasing yields(e.g., through the use of fertilizer) or obtaining a higher farm-gate price by improving the quality ofrubber. Nevertheless, the current expansion is clearly vulnerable to a price downturn.
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CONCLUSION
The findings suggest that the bigger plantations can generate more income than the smaller
plantations due to a difference in output production. Medium-size producers tend to produce latex
that are more likely to be in demand by the factory. This type of produce is identified as a highgrade rubber that is commonly used for high-end products. In contrast, small-size producers sell
their produce as coagulum used in the tire industry, and they are usually purchased by middlemen.
In the current market, the price of latex is twice as profitable than coagulum rubber. However, thesmall-size producers prefer to sell their produce as coagulum in order to receive cash-in-hand,
while the big factories prefer to purchase the latex only from the medium to large-size plantations
to secure the quality as well as the quantity.
Further findings also show that despite the continuously decreasing price of rubber, rubber
production is still seemingly economically feasible. However, if the price continues to decrease,rubber producers will struggle to recover the initial investment from the rubber plantation as thepayback period is getting longer. From the results, it can be concluded that the investment for
rubber plantations is getting riskier, and small-size producers are likely to be at the mostdisadvantaged. Upon weak market channels, rubber producers are not proactively addressing any
potential risks, with even the slightest changes to input costs (labor, fertilizer, herbicide, and latex
stimulant) having the potential of posing a major threat for rubber producers.
Smallholder rubber plantations usually have no control to dictate the price of their produce, as
farm gate prices are usually set by collectors and traders. Therefore, the development of proper fairmarket channels and support from the government should be established to sustain the rubber
producers’ livelihoods and to mitigate any potential future risks. Support such as subsidies andquality material inputs should be accessible and available to rubber producers, especially during theestablishment period when producers cannot generate any income.
Relevant and timely information on local and international rubber markets and rubber
feasibility investment reports should be provided to rubber producers. Moreover, information suchas potential markets and required standards should be informed to all rubber producers. Using thelatest information and techniques can help rubber producers during the investment making
processes and increase their productivity and income, potentially protecting the producer’s
livelihoods in the long run.
To further address this study, a study on the biophysical components (weather, soil, intercrop
system, and clone) should be conducted in order to determine the factors that may affected farmer
decision on output produce.
ACKNOWLEDGEMENTS
The authors acknowledge Tokyo University of Agriculture for financially support this research. We
are also would like to express our gratitude to all the officials from the General Directorate of
Rubber and the participants for their cooperation during the field survey.
REFERENCES
ADI. 2007. Key regulatory constraints in the marketing of processed and unprocessed rubber in Cambodia.
Phnom Penh, Cambodia.
Campbell, H. and Brown, R. 2003. Benefit-cost analysis: Financial and economic appraisal using
spreadsheets. Cambridge University Press, Cambridge.
GDR. 2014. General directorate of rubber annual report for 2013 and direction for 2014. Cambodia.
Hor Kimsay and Renzenbrink, A. 2013. Cambodian rubber earnings fall. The Phnom Penh Post, Retrived
from http://www.phnompenhpost.com/business/cambodian-rubber-earnings-fallHing ,V. and Thun, V. 2009. Agricultural trade in the Greater Mekong Sub Region: The case of cassava andrubber in Cambodia. CDRI Working Paper Series, No. 43, Retrived from www.cdri.org.kh/webdata/
download/wp/wp43e.pdf
MAFF. 2008. Annual report 2007-2008. Ministry of Agriculture, Forest and Fisheries, Cambodia.
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MoC. 2013. Cambodia’s diagnostic trade integration strategy 2014-2018. Ministry of Commerce, Cambodia.
Natividad, R. 2016. Consequences of Cambodia’s rubber boom: Assessing the governmental, environmental
and human rights violations in the industry’s current regulatory framework. 40, Wm. & Mary Envtl. L. &Pol'y Rev, Retrived from http://scholarship.law.wm.edu/wmelpr/vol40/iss3/8
World Bank. 2017. World bank commodities price forecast (US dollars). Retrived from http://pubdocs.
worldbank.org/en/662641493046964412/CMO-April-2017-Forecasts.pdfⒸ ISERD

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Research article
erd

Factors Affecting Farmers` Decision on Crops Selection
with Special Reference to New Technology: Case of
Sunflower Seed and Sweet Potato in Ikungi District,Tanzania
RUBASHA MATIKU MUJAMA*
Graduate School of Agriculture, Tokyo University of Agriculture, Tokyo, Japan
Email: mujamarubasha85@gmail.com

YOICHI IZUMIDA
Faculty of International Agriculture and Food Studies, Tokyo University of Agriculture, Japan
Received 15 December 2018

Accepted 27 August 2019(*Corresponding Author)

Abstract The main objective of this paper is to investigate why the sharp decline ofsunflower seed production had occurred just after the starting of modern varieties
promotion policy in Tanzania. Specifically, the study aims to (1) examine the changes in
production of sunflower seed crop and that of its substitutable crop (sweet potato) for ten
years, (2) determine the differences in profitability between sunflower production withmodern varieties and production of related crops (sunflower seed with traditional varieties,
and sweet potato), (3) examine the effect of relative price changes, (4) clarify other related
factors such as famers’ characteristics in the adoption of new technologies, contract farming,and limited capacities of oil processing sectors. The field study was conducted in Marchand September 2018, selecting 270 farmers from three villages in Ikungi District. Based on
the data obtained in the 2018 field study, profitability of the three types of cultivation was
calculated. The result shows that sweet potato farmers received the highest economic returnin terms of gross profit (545.7 TZS/ha) than sunflower farmers with modern seed varieties(397.0 TZS/ha). Sunflower farmers using traditional varieties received the lowest (273.7
TZS/ha). Furthermore, it was confirmed that changes in the farm gate prices over time had
influenced profitability of three types of farming. At the starting time sunflower production
with modern technologies had its advantage against sweet potato production. Farmers’ crop
selection is mostly rational but institutional factors like contract farming and limited
capacity of processing sector were the barrier for the change. Also, it was suggested that
farmers need more education and training for more rational crop selection. Finally, fromthis case policy makers have to know that if the conditions are not well fulfilled thepromotion of new technology may not have the desired result.
Keywords crop selection, new technology, sunflower seed, sweet potato, contract farming,
Tanzania

INTRODUCTION
Adoption of modern technologies such as chemical fertilizers, pesticides, and improved seeds is aneffective pathway to enhance the welfare of farmers through attaining higher productivity (World
Bank, 2008). Following this idea, the government of Tanzania set up new agricultural policy of
promoting modern seeds for sunflower producers in 2009. Due to its low level of cholesterol,
sunflower oil is highly preferred as edible and safe cooking oil for many households in the country.
The crop accounts 40% of the total national cooking oil requirements (URT, 2014). The country
attempted to reduce the burden of importing edible cooking oil from foreign countries by offering
opportunities of high yield varieties together with aim of income generation to farmers. The
government promoted the adoptions of modern varieties through extension services and contract
farming (URT, 2014). Despite the efforts done by the government of Tanzania to set up newⒸ ISERD

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agricultural policy of promoting modern seeds for sunflower producers, the production has been
decreasing.
OBJECTIVES
The main objective of this paper is to investigate why the sharp decline of sunflower seedproduction had occurred just after the starting of modern varieties promotion policy in Tanzania.
Specifically, the study aims to (1) examine the changes in production of sunflower seed crop andthat of its substitutable crop (sweet potato) for ten years, (2) determine the differences in
profitability between sunflower production with modern varieties and production of related crops(sunflower seed with traditional varieties, and sweet potato), (3) examine the effect of relative pricechanges, (4) clarify other related factors such as famers’ characteristics in the adoption of newtechnologies, contract farming, and limited capacities of oil processing sectors.
METHODOLOGY
The field study was conducted in Ikungi District, one of the three districts of Singida region in
March and September 2018. This region is selected because new technology has been promoted
through extension services and contract farming to sunflower farmers since 2018. Based on theobservation, it was found that there were three types of sunflower seed related farmers; i) sunflower
farmers still using new technology; ii) sunflower farmers with traditional varieties iii) and farmers
who changed from sunflower production using new varieties into sweet potato. Considering thisobservation, a total of 270 farmers from three types of groups were selected randomly from a list of
farmers in the respective three villages: Damankia; Nkwiree; and Ikulume. Among them, 90
farmers from each village were selected from each category of farmers (30 sunflower farmers withnew technology; 30 sunflower farmers with traditional varieties; and 30 farmers who changed fromgrowing sunflower with new varieties to grow sweet potato)
In the field survey in March 2018, production data were collected through interviews with
farmers. Additional information was obtained from the discussion with key informants such as
traders, processors, and extension workers. The major information collected included: farmers’
characteristics, cost and sales conditions of producers, and current problems and future prospects.
The second interview were carried out in September 2018 in order to probe more information on
the processing industries and area of contract farming that promote new technology among
sunflower farmers.
RESULTS AND DISCUSSION
1) Changes in Production of Sunflower Seed Crop and Sweet Potato

Fig. 1 Changes in production of sunflower seed and sweet potato in
Tanzania (2000-2017)
Source: Country FAO-Statistics, 2018
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In 2011, sunflower seed production increased significantly to more than 790,000 tons from 380,100
tons in 2010. But, from next year sunflower seed production had sharply declined continuously toless than half in 2017, comparing its peak in 2011 as shown in Fig. 1.
2) Features of the Farmer-Respondents
From the field study it was found that sunflower farmers with traditional varieties was older (45.2
years) compared to sunflower farmers with modern varieties (39.4 years) and sweet potato
producers who transformed production from sunflower producing (37.3 years). Furthermore, withrespect to the farm size, traditional sunflower producers were relatively small (0.83 ha), sunflower
farmers with modern varieties was (1.21 ha) and farmers who changed production into substitutable
crop (sweet potato producers) was higher (1.52 ha) as shown in Table 1.
The study went further to observe farmers’ educational background because this is one of themost important factors for farmers to manage their farms in smartly move. Educational backgroundof heads of household was grouped based on the education system of the country. There was highimprovement in education for heads of household producing sweet potato whereas more than(80%) have reached to high school level and university level. Also, more than (8%) of sunflower
farmers with modern varieties have reached to high school level and university level. But, majorityof heads of household (98%) producing sunflower using tradition varieties have reached to primarylevel and secondary level only (Table 1).
Table 1 Features of the farmer-respondents
Tradition sunflower
varieties producers(n=90)
Mean
SD

Modern sunflower
varieties producers(n=90)
Mean
SD

Sweet potato
producers(n=90)
Mean
SD

Characteristics
Age of heads ofhousehold (years)
Averagecultivatedarea (ha)Genderoffarmers
Male
Female

45.20

8.09

39.40

7.81

37.30

6.53

0.83
Numberoffarmers74
16

0.42
Percentage
offarmers
82.2
17.8

1.21
Numberoffarmers58
32

0.64
Percentage
offarmers
64.4
35.6

1.52
Numberoffarmers67
23

0.71
Percentage
offarmers
74.4
25.6

Farmers' education
Primary level
Secondary level
High school level
College level
University level

87
2
1
0
0

96.7
2.2
1.1
0.0
0.0

40
42
3
4
1

44.4
46.8
3.3
4.4
1.1

13
60
8
6
3

14.5
66.7
8.9
6.7
3.3

Source: Field survey, 2018
Note: (1) SD refers standard deviation (2) Primary level is seven years of schooling (3) Secondary level is four years ofschooling (4) High school level is two years of schooling (5) College level is two years of schooling (6) University level isthree to four years of schooling.

Concerning the gender of the household head, the study shows that heads of householdproducing sunflower seed with tradition varieties (82.2%) were male and (17.8%) were female. In
the cases of other two types, more participation of female in new sunflower varieties (35.6%) isbigger than in sweet potato production (25.6%). This suggest that more participation of female tend
to move to new technology adoption; that may be because farmers` education was higher than othertypes of farmers.

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3) Differences in Profitability
In order to understand the profitability of two crops, the gross income and gross profit were
calculated based on the data obtained in the field survey 2018. Gross income is calculated as agross revenue minus total production cost excluding family labor cost. Gross profit is calculated as
gross income deducting family labor cost. With respect to the estimation of family labor cost,
opportunity cost was applied. In the cost calculation depreciation were not considered since farmers
in the studied area did not use modern machinery in agricultural activities. The result revealed that,
there were significant differences in income and profit among the three types of farmers. The sweet
potato farmers receive the highest economic return in terms of gross profit (545.7 TZS/ha) thansunflower farmers with modern sunflower seed varieties (397.0 TZS/ha). Sunflower production
using traditional varieties received the lowest (273.7 TZS/ha) (Table 2).
Table 2 Profitability comparison of sunflower seed and sweet potato in 2017
Item
Head of household
Yield (tons/ha)
Seeds cost
Chemical fertilizer cost
Pesticide cost
Hired labor cost
Total variable cost
Family labor cost
Total labor cost
Total production cost
Gross Revenues (GR)Gross Income (GI)Gross Profit (GP)

Tradition
sunflower
varieties
users (a)(n=90)
1.2
10.6
22.7
0.0
23.4
56.7
41.6
65.0
98.3
372.0
315.0
273.7

Modernsunflower
varieties users(b)(n=90)
1.8
18.2
37.9
10.8
27.9
94.9
50.1
78.0
145.0
542.0
447.1
397.0

Sweet
PotatoProducers(c)(n=90)
2.0
10.3
0.0
9.3
23.7
43.3
45.8
69.3
89.1
634.5
591.4
545.7

Source: Survey, 2018

Comparison

(b-a)

(c-b)

(c-a)

0.6
7.6
15.2
10.8
4.5
38.2
8.5
13.0
46.7
170.0
132.1
123.3

0.2
-7.9
-37.9
-1.5
-4.2
-51.6
-4.3
-8.7
-55.9
92.5
144.3
148.7

0.8
-0.3
-22.7
9.3
0.3
-13.4
4.2
4.3
-9.2
262.5
276.4
272.0

Unit of cost: `000TZS/ha

Table 3 Farmgate price changes of sunflower seed and sweet potato (100 =2007)
Year

Price index ofsunflower seed

Price index ofsweet potato

2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017

100.0
99.4
102.9
113.2
102.9
102.6
102.1
97.1
91.2
88.2
87.6

100.0
106.7
100.0
103.3
120.0
121.7
123.3
124.0
124.0
125.0
127.3

Source: SDC, 2018

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Relative price index ofsunflower seed
100.0
93.2
102.9
109.6
85.8
84.4
82.8
78.3
73.5
70.6
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Of course, the significant differences in profitability among three types in Table 2 were basedon the data in 2017. Prices of sunflower seed and sweet potato had changed as shown in Table 3.
Relative price of sunflower seed comparing with sweet potato has been declining as indicated inTable 3. At the starting year 2010, the profitability of sunflower seed might be better than sweet
potato. In order to check this, the study simulated the comparative profitability of sunflower seed tosweet potato in various years with the following assumption: Farmers cultivated sunflower seed
and sweet potato by using same technologies as in 2017 (then the cost and yield same as that in2017), but the selling prices differ. The economic return in each year were calculated by replacing
the farmgate price of 2017 by the price of corresponding year. The result shows that if the output
price level was the same as that in 2010, the sunflower production with modern varieties ranks firstin profitability (gross income and gross profit) and sweet potato production ranks in the second
place. Profitability of sunflower production with traditional varieties was the lowest. In 2011, theprice of sunflower seed sharply declined as in Table 3 and the sunflower production with modern
technologies lost its advantage against sweet potato production.
4) Other Related Factorsi) Limited absorption capacity of processing sector:
Capacity building of various institutions especially in agriculture is important factor to ensure
efficiency and effectiveness in service delivery. In Tanzania sunflower oil processing sector isfacing a big challenge of limited capacity to absorb farmers’ produce. Direct interviews withsunflower processors revealed that the three processing companies in the studied area only had total
annual absorption capacity of 12,420 tons. However, this capacity could not absorb sunflower
farmers’ produce of 35,700 tons in (2017) in the studied area. This evidence is supported by other
scholars that in Tanzania, absorption capacity of processing sector is limited and most of the local
investors are not moving fast enough to invest in agricultural processing. Meanwhile foreign
investment is not attracted sufficiently (Mpagalile, 2012).
ii) Contract farming:
As noted earlier in 2017, though differences in profitability was apparent among three types offarming, it observed that still some sunflower producers did not change the crop selection.
Sunflower production with new technology is dominated by the production contract that
established in 2010 with specific goal of promoting new technology to sunflower farmers. In thiscontract, the company provides agricultural inputs, agricultural extension services and sometimes
credit to sunflower farmers together with new technology. Likewise, the period of contract is eight
years. Major actors in the governance of sunflower contract farming are sunflower farmers withnew technology, company providing contract, and the government of Tanzania. Based on thefindings through direct interviews with sunflower farmers it observed that on the regularity ofcontract farming, farmers who want to terminate the contract before time must be punished throughthe contract law. This clearly show that sunflower farmers with new technology still continue theproduction because of the existence of contract farming.
iii) Characteristics of sunflower farmers with traditional varieties:
It has been pointed out that, although sunflower farmers with traditional varieties received thelowest profit but still continue the production. Table1 indicated that the sampled sunflower farmers
using local varieties was more aged (45.2 years), relatively small in size, and less educated. Due tothese features, they may be more reluctant to changes in adoption of new technologies. This is
supported by other scholars that young farmers are more knowledgeable on better practices andmay be more ready to adapt to better farming techniques because of their willing to achieve moreproduction in their fields (Abunga, et al., 2012).
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The main objective of this paper was to investigate why the sharp decline of sunflower seedproduction had occurred just after the starting of modern variety promotion policy in Tanzania. It
was found that changes in the farm gate prices over time had influenced the sunflower production
with modern technologies lost its advantage against sweet potato production. In other words,
farmers’ crop selection is mostly rational but institutional factors such processing sector andcontract farming were the barrier for the change.
In relation to the finding and conclusion the following were recommended so as alleviate theexisting challenges by all stakeholders of this sector. First, there is a definite need for thegovernment of Tanzania to consider the area that absorb farmers’ produce after production.
Therefore, policy makers have to know that if the conditions are not well fulfilled the promotion of
new technology may not have the desired result. Also, farmers need more education and training
for more rational crop selection. Lastly, the area of sunflower contract farming should be revised toenhance its efficiency in new technology provision among sunflower farmers.
ACKNOWLEDGEMENTS
We would like to express our gratitude to Moritani Memorial Foundation and Graduate Research
Funding Program from Tokyo University of Agriculture Research Institute (NRI) for financially
supporting this study.
REFERENCES
Abunga, M., Emelia, A., Samweli, G. and Dadzie, K. 2012. Adoption of modern agricultural production
technologies by farm households in Ghana. What factors influence their decision? Journal of Biology
Agriculture and Healthcare, 2 (3), 1-13. Retrived from www.iiste.org/Journals/index.php/JBAH/article/viewFile/1522/1454
Hayami, Y. and Herdt, R.W. 1977. Market price effects of technological change on income distribution insemi subsistence agriculture. American Journal of Agriculture economy, 59, 245-250.
Mpagalile, J. 2012. Agribusiness innovation systems in six African countries, The Tanzania Experience,
Sokoine University of Agriculture, Morogoro, Tanzania.
Myers, R.L. 2002. Sunflower: A native oilseed with growing markets. Online document, Retrived fromwww.jeffersoninstitute.org
Rutatora, D. and Mattee, A. 2001. Major agricultural extension providers in Tanzania. African Study
Monographs, 4, 155-170.
SDC. 2018. The three- year development plan 2014-2017 for Singida District, Tanzania. Singida District
Council, Tanzania.
TNBC. 2009. Ten pillars of agricultural first (Kilimo Kwanza). Tanzania National Business Council, Dar es
Salaam, Tanzania.
URT. 2014. Agriculture sector review and public expenditure review 2013/2014, United Republic of
Tanzania. Ministry of Agriculture and Food Security, 111, Dar es Salaam, Tanzania.
Wambura, R.M. and Kapinga, D. 2008. The experience of farmers` organizations in promoting ruraldevelopment in Tanzania: A case of small farmers groups in selected villages of Morogoro Region. Rural
Planning Journal, 7 (1), 13-24.
World Development Report. 2008. World development report: Agriculture for development. World Bank
Group, Washington DC, USA.

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Research article
erdContent of Online Marketing that Influence Customers`
Decision: A Case on Buying Indigo-Dyed Clothing
SARANYA SAETANG*
Kasetsart University, Thailand
Email: saranya.sa@ku.th
Received 4 February 2019

Accepted 27 August 2019(*Corresponding Author)

Abstract Nowadays, technology plays a significant role in business success. Technologies,
including the Internet, web application, and social media can help to grow business by
expanding distribution channels to reach customers, even in rural areas. In addition totechnology, an online place to promote trade and the content of the products should beconsidered to help customers in buying decision processes. This research is conducted tounderstand how to create a proper content to promote online marketing. Consequently,
good content can help to decrease the burden of web administrators who have to answer all
frequently asked questions from customers. This paper begins with a literature review.
Then, by using the focus group method, the customers’ factors were identified on buying
experiences of indigo-dyed clothing, which is a popular product in the Northeastern regionof Thailand. Moreover, the interview of an administrator of an indigo-dyed clothing’s web
page as a purposive sample was summarized. By using content analysis, the results suggest
some broad guidelines to present the content to promote products to gain the customers’
response and interest. The conclusion and future work will be mentioned to contribute to
the academics and the sellers to sustain online businesses.
Keywords impact, content marketing, buying decision, e-commerce, indigo-dyed clothing

INTRODUCTION
E-commerce or online marketing could reduce economic inequality for people in a rural area to set
up their businesses with limited marketing resources. However, e-commerce itself could not be areason that a product could be sold. One factor that has an impact on the buying decision-making
process is product content. It affects customer satisfaction (Saetang, 2017). In turn, it will influence
the consumer buying decision, especially the process of information search (Stankevich, 2017).
This paper aims to study on what content that customers’ interests for helping them to make such abuying decision. The paper will begin by reviewing previous studies as follows.
Consumer Decision Making Process
From a critical literature review of Stankevich (2017), consumer decision making processes
compose of 5 main processes, including need recognition, information search, evaluation ofalternatives, purchase, and post-purchase. The information search process is a crucial process forgathering information about the description of products, promotion, recommendations, and reviews
from other customers and the experience of using the products. All these pieces of information
have an impact on the buying decision-making process.
Indigo Dyed Clothing
Indigo dyed clothing was chosen to be a case study as this local product is very famous inNortheast Thailand mainly, in Sakon Nakhon province. Indigo dyed clothing helps agriculturists
generate more income apart from farming. In 2001, the Thai government encouraged local
communities to apply their local knowledge and create a product that represents their localⒸ ISERD

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communities through the campaign called “One Tambon (sub-district), One product.” This
campaign is to boost local economies for each community (Chanjittra Chanorn, 2016). Indigo dyed
clothing was selected as one product for the Sakon Nakhon province since it uses local wisdom
inherited from generation to generation to produce cloth and can increase household income. Its
fabric has its unique indigo color, odor, and properties, which make it unique and famous. It wasdyed with an indigo tree and can help prevent Ultra Violet rays (Phuphat, 2012).
Indigo dyed clothing is one of the experience goods that customers should have experience
with the products before buying. Otherwise, they will not recognize the quality and will not beinterested in buying. However, there are many online stores and communities that sell indigo dyed
products such as scarves, shirts, skirts, and bags. The example could be seen as the following Fig. 1.

Fig. 1 An example of online stores (Ban Non Ruea, Sakon Nakhon) for indigo dyed products
Even though village product promotion has many advantages and brings more income tocommunities, one major problem that arises for this campaign is that village producer groups haveno experience with product development and marketing (Chanorn, 2016). Therefore, somecommunities failed to sell their products in spite of the support from governments.
Marketing is the key to success, which villagers, including indigo-dyed clothing sellers, haveto deal with. One problem is they are naïve to business and do not know how to sell their products
or how to communicate with customers. Content marketing could be an inexpensive way to sell
products online. Creating the right content could reduce the workload upon answering theircustomers ’ frequently asked questions and can have more time to develop products.
This study focuses on this indigo-dyed clothing to assist naïve sellers who want to start their
online businesses, but still not know what content or information that customers needed the most in
particular, for experience goods such as indigo fabric. Some results of this study could give someguidelines for creating interesting online content for customers.
Content Marketing
Content marketing could be defined as the pull strategy that provides consumers about themarketing information that is relevant, educational, helpful, engaging, needed, and sometimes
entertaining without hard-sell advertising (Lieb, 2011). Nowadays, hard-sell advertising is notselling. The companies should give only a piece of content or information that serve theircustomers’ need. In turn, it will make a customer return to the companies for that helpful
information and have more intention to buy their products. Then, some questions were raised inmind; for example, what is the information that customers need or what kind of information weshould provide for customers.
The work of Resnik and Stern (1997) has defined what is considered to be useful information
for advertising in general. They identified 14 criteria for evaluating advertising content as 1. Priceor value 2. Quality 3. Performance 4. Components or contents 5. Availability 6. Special offers 7.
Taste 8. Packaging or Shape 9. Guarantees or warranties 10. Safety 11. Nutrition 12. Independent
research, 13. Company-sponsored research, and 14. New ideas.
Additionally, the work of Gupta et al. (2004) shows that the factors that influence consumer
switching from offline to an electronic channel are the ease of online price and information searchⒸ ISERD

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to evaluate the products. Moreover, delivery time and free express delivery are considered foronline consumers. Furthermore, the study suggests that trust has an impact on purchase intention,
especially for the experience goods (i.e., Ones that consumers would rather physically examine
before making a buying decision).
Moreover, the global online consumer report (KPMG International cooperative, 2017) showsthat reasons that consumers buy things online instead of in stores are the convenience and theability to compare and gain a better price. Moreover, it suggests that the information that
consumers are looking up for information about products are price comparison, productinformation or specification, reviews, product options (e.g., color, size, style, etc.) and store
inventory/ availability. The report also shows that when consumers decide where to buy products
depends on the best price, preferred website, best delivery options or price, stock availability, peeradvice, and returns policy.
From the previous work above, it can be identified the essential and relevant content thatshould be included to promote experience products like indigo-dyed clothing to facilitate thebuying decision making are: 1. Prices 2. Quality and product information 3. Availability 4. Special
offers 5. Reviews 6. Packaging or Shape 7. Guarantees or warranties / Return policy, and 8.
Delivery time and fee.
OBJECTIVE
This research is conducted to study how to create content to respond to customer’s needs and could
help customers on buying decision processes by using indigo-dyed clothing as a case study. The
good content, in turn, could help to reduce the workload of the online products’ owner to answer all
frequently asked questions. This study tried to identify the ways to create content that supports
customers in their buying decision making. The methodology will be presented in the next section.
METHODOLOGYThis study referred to previous work, applied focus group, and interview as research methods.
A focus group was used to identify the customers’ factors on the experiences of indigo-dyed
clothing’s buying decision. Indigo dyed clothing is an experience good which people have been
buying experience before. A focus group is a useful tool used in marketing to collect peoples’
opinions, attitudes, and feelings on a given topic (Dilshad and Latif, 2013). A group of 10 persons
who used to buy indigo-dyed clothing was asked questions about what information they used tomake a buying decision on indigo dyed clothing and what channels (online/ offline shops) that theyused to buy.
Moreover, the interview of an administrator, who is experiencing online selling of indigo-dyed
clothing, on what information she used to be asked the most from customers was summarized inTable 1.
Sample groups in this research were selected using purposive sampling because of the limited
numbers of customers and web administrators (sellers) and a group of people who experience andwant to give information for the research. Thus, this research has a sample limitation and could befurther expanded to collect more samples.
The results using content analysis suggest some ways to present the content to promote
products in order to gain the customers’ response and interest.
RESULTS AND DISCUSSION
The content that was considered when buying indigo-dyed clothing from previous work wasanalyzed and presented as in Table 1. Which is (unordered data): 1. Prices 2. Quality and productinformation 3. Availability 4. Special offers 5. Reviews 6. Packaging or Shape 7. Guarantees orwarranties/Return policy, and 8. Delivery time and fee.
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Table 1 The information that was considered when buying indigo-dyed clothingfrom the literature review
1
2
3
4
5
6
7
8

Literature review
Prices
Quality and product information
Availability
Special offers
Reviews
Packaging or Shape
Guarantees or warrantees / Return policy
Delivery time and fee

Additionally, the results from the focus group summarized by content analysis are presented inTable 2. The group of purposive samples indicates that the styles (e.g., patterns, appearance), texture
and smell of indigo plants, shop name or brand, and price are important information that focus groupmembers considered when they make an indigo-dyed clothing buying decision, respectively. Oneof the samples said, “styles of the cloths” is the most crucial factor in buying them.
Table 2 The information that was considered when buying indigo-dyed clothing
Importance
1
2
3
4
5
6

Interview an administrator of online indigo
clothing seller
Products’ information (i.e. Dimensions)
Patterns and Styles
Buying channels/methods
Fabric care methods
Price
Address and Map of shops

Focus group“Styles” (e.g. Patterns, appearance)“Texture and smell of indigo plants.”“Shop name/ Brand.”“Price”“Friends’ recommendations.”

From interviewing an administrator of a web site that sell indigo-dyed clothing, theinformation that was asked most frequently about indigo-dyed products are products’ informationsuch as dimensions and color, patterns and styles, buying channel or methods to buy, fabric care or
how to take care the indigo-dyed clothing, price, address and map of the shop, respectively.
The results from the focus group and the interviews indicate that styles and patterns are the mostimportant information (more than price) that customers will use to make their buying decisions since
it will make customers happy and confident when wearing it. They will pay for cloth if it makes themgood looking. Therefore, as an online shop, photos of the products and information needed to beprepared carefully. They have to be a clear picture with natural light and make people appreciatedwith.
Moreover, it can be seen that as an online shop where we cannot see each other face to face,some factors that increase trusts such as shop name or brand, address and map of shops, and friends’
recommendations are also important. All in all, from the above literature review on the section ofcontent marketing (summarized in Table 1.), focus group and interview (summarized in Table 2.),
information that should be provided for customers is all information as follows: 1. Prices, 2. Styles,
patterns, texture, and product information, 3. Availability, 4. Special offers, 5. Reviews, 6.
Packaging or Shape, 7. Guarantees or warranties / Return policy, 8. Delivery time and fee; 9. Shop
name/ Brand, 10. Address and map of shops, 11. Buying channels/ methods, and 12. Fabric caremethods.
All information (altogether from table 1 and 2) that should be provided for customers to help
them make a buying decision for indigo-dyed clothing could be separated into 2 groups: 1.
Information that is related to products including prices, styles, patterns, texture and productinformation, availability, special offers, packaging or shape, guarantees or warranties/return policy,
delivery time and fee, buying channels/ methods, and fabric care methods, and 2. Information that
increase trust including reviews, shop name/ brand, and address and map of shops. These kinds ofⒸ ISERD

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information could help customers accelerating a decision on buying processes and reducing
workload to answer all frequency asked questions from customers.
LIMITATIONSThe samples of the interview were selected using purposive sampling since there was little time to
conduct this study. However, some lesson was learned and gained some guidelines for an
administrator of any website to create content and provide some helpful content and information for
their customers.
CONCLUSION
Online marketing could help people in rural areas sell their products with limited resources andinvestment. However, nowadays, hard-sell advertising could not gain a high purchasing demand
anymore; some marketing techniques have to be adopted. This study focuses on how to provide
practical content that is useful and helpful for customers to make a quicker buying decision on
indigo-dyed clothing. From previous work, focus group, and interviewing an administrator who
sells indigo dyed fabric online, there are 2 kinds of information that should be provided forcustomers to facilitate indigo-dyed clothing’s buying processes online, which are 1. Informationthat is related to products ,including prices, styles, patterns, texture and product information,
availability, special offers, packaging or shape, guarantees or warranties / return policy, delivery
time and fee, buying channels/ methods, and fabric care methods and 2. Information that increase
trust, including reviews, shop name/ brand, and address and map of shops.
ACKNOWLEDGEMENTS
This paper is grateful to Kasetsart University and the Ministry of Science and Technology for being
sponsors and facilitating the work.
REFERENCES
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Research article
erd

The Impact of Agricultural Export Product on Income and
Employment in the Thai Economy
ANUCHA WITTAYAKORN-PURIPUNPINYOO*
School of Agriculture and Cooperatives, Sukhothai Thammathirat Open University,
Parkkred Nontaburi, Thailand
Email: puanucha@windowslive.com
Received 26 December 2018

Accepted 20 October 2019(*Corresponding Author)

Abstract From past to present, the Thai economy has been heavily export-dependent, with
exports accounting for more than two-thirds of its gross domestic product (GDP).
Agricultural export product is one of the main export products but its tendency is declining.
The research objectives were to study the impact of agricultural export products on theincome and employment of the Thai economy. In this research, the data applied werecollected as the yearly time series for a period of 27 years from 1990 to 2016 by the Bankof Thailand. The primary data were collected from the stakeholders of the agricultural
product export policy of Thailand. Data analysis was based on descriptive statistics by thearithmetic mean and standard deviation. The Monte Carlo Simulation technique and timetrend analysis was applied to the forecasting of agricultural product export value. In
addition, the impact of agricultural export product on income and employment measured by
the econometric model and the estimated parameters were calculated by the ordinary leastsquare technique. The research results revealed that: agricultural export product value ofThailand from 1990 to 2016 was $10.270 billion with its yearly growth rate of 4.984
percent, in addition, the forecasting of agricultural product export value of Thailand has
increased but its growth rate has declined. The impact of agricultural export products has apositive impact on income in the Thai economy; agricultural product export value ofThailand increased 1 percent which, in turn, led to the income increase by 0.0051 percent.
In addition, the impact of agricultural export product value has a positive impact on
employment in the Thai economy; agricultural export product value of Thailand increased 1
percent which, in turn, led to the employment increase by 0.079 percent. The Thai
agricultural export product policy should be focused on finished or semi-finishedagricultural products instead of raw materials by applying technology and innovation to
make value-added agricultural product export.
Keywords agricultural export product, income, employment, Thai economy

INTRODUCTION
Thailand is a newly industrialized country. Its economy is heavily export-dependent, with exports
accounting for more than two-thirds of its gross domestic product (GDP). In 2014, according to the
Office of the National Economic and Social Development Board, Thailand had a GDP of 92.11
trillion baht (US$366 billion). The Thai economy grew by 8.5 percent, (the Office of National
Economic and Social Development Board, 2016) with a headline inflation rate of 3.02 percent andan account surplus of 0.7 percent of the country's GDP. In 2016, the Thai economy is expected to
grow in the range of 3.8 to 4.3 percent (Bank of Thailand, 2016).
The industrial and service sectors are the main sectors in the Thai gross domestic product,with the former accounting for 39.2 percent of GDP. Thailand's agricultural sector produces 8.4
percent of GDP—lower than the trade and logistics and communication sectors, which account for13.4 percent and 9.8 percent of GDP, respectively. The construction and mining sector adds 4.3
percent to the country’s gross domestic product. Other service sectors, including the financial,education and hotel and restaurant sectors, account for 24.9 percent of the country's GDP. (Bank ofThailand, 2016).
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In addition, telecommunications and trade in services are emerging as centers of industrial
expansion and economic competitiveness (World Bank, 2016). Thailand is the second-largest
economy in Southeast Asia with a GDP per Capita of $ 5,490 (The Office of National Economic
and Social Development, 2016). Thailand ranks second in Southeast Asia in external trade volume,
after Singapore (World Trade Organization, 2016). Thailand has been the largest rice exporter inthe world. Forty-nine percent of Thailand's labor force is employed in agriculture (Henri et al.,2010). Developments in agriculture since the 1960s have supported Thailand's transition to anindustrialized economy (Henri et al., 2010).
As recently as 1980, agriculture supplied 70 percent of employment (Henri et al., 2010). In
2008, agriculture, forestry, and fishing contributed 8.4 percent to GDP; in rural areas, farm jobs
supply half of employment (Henri et al., 2010). Rice is the most important crop in the country and
Thailand had long been the world's number one exporter of rice, until recently falling behind both
India and Vietnam (International Grain Council, 2014). It is a major exporter of shrimp. Other
crops include coconuts, corn, rubber, soybeans, sugarcane, and tapioca (New York Times, 2010).
Thailand is the world's third-largest seafood exporter. Overall, fish exports were worth around
US$3 billion in 2014, according to the Thai Frozen Foods Association. Thailand's fishing industry
employs more than 300,000 people (Lefevre et al., 2015). In 1985, Thailand designated 25 percent
of its land area for forest protection and 15 percent for timber production. Forests have been set
aside for conservation and recreation, and timber forests are available for the forestry industry.
Between 1992 and 2001, exports of logs and sawn timber increased from 50,000 to 2,000,000 cubic
meters per year. In 2014, industry contributed 50.3 percent of GDP, employing 16 percent of theworkforce. The industry expanded at an average annual rate of 4.4 percent. The most important subsector of the industry is manufacturing, which accounted for 38.5 percent of GDP in 2014 (Bank ofThailand, 2016).
Thailand’s strategic location makes it an investors’ gateway to Asia. It is at the center of most
ASEAN countries, including Myanmar to the west, Cambodia and Lao PDR to the east, andMalaysia, Indonesia, and Singapore to the south. Being at the crossroads of ASEAN and otherdynamic markets in Asia, such as China and India, allows Thailand access to a burgeoning
consumer population overseas aside from its equally huge population of almost 68 million people.
Thailand offers investors a world-class infrastructure. Trade and business transactions are madeeasier through Thailand’s extensive highway system, modern city-wide mass transit, international
airports, deep seaports, and international river ports. As the hub of ASEAN, Thailand advocates forfree and fair trade. It is instrumental in the formulation of the ASEAN Free Trade Area and asignatory to a number of other free trade agreements. Business opportunities in Thailand areabundant across several industries which include automotive, alternative energy, food, electrical &electronics, logistics, printing, yacht building, rubber industry, etc. (Thailand Board of Investment,
2016).

(AgEx /GDP) (Percentage)

16

AgEX/GDP (%)

14
12

10
8
6
4
2
2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

1998

1997

1996

1995

0

Year

Fig. 1 The value of agricultural export per gross domestic product (GDP)
Source: CalculationⒸ ISERD

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From past to present, the basis of the Thai economy has been heavily dependent on the
agricultural sector. The agricultural sector is still part of food production, clothes, raw materials,
and labor to serve other sectors in the economy. Obviously, the Thai economy mainly relies upon
the export sector. About 80 percent of Gross Domestic Product (GDP) stems from the export sector.
This means that the Thai economy has been and still depends on the export sector which generated
the National Income and GDP growth rate. According to the Thai economy, there were 2-main
sectors which are Agricultural and Non-agricultural sectors Industrial sub-sector, financial subsector, and service sub-sector. The non-agricultural sector generated about 95 percent of GDP
while the agricultural sector generated about 5 percent of GDP. Statistically, from the last 20 years,
the agricultural sector has been smaller than it was. The ratio of Agricultural export per GDP has
been declined (Fig. 1).
In this research, the researcher tries to examine the impact of agricultural product export onincome and employment in order to determine the future shape of the agricultural sector as a part of
the Thai economy.
OBJECTIVE
The research objectives are as follows:
1) to find out the impact of agricultural export product on the income of the Thai economy2) to find out the impact of agricultural export product on the employment of the Thai economy
METHODOLOGY
Data Collection
The secondary data time-series data from 1998 to 2017 accounted for 20 years were collected fromthe database of Bank of Thailand, the Office of National Economic and Social Development andthe Office of Agricultural Economics (OAE), the Ministry of Agriculture and Cooperatives, theRoyal Thai Government.
Data Analysis
The impact of agricultural export products on income and employment was calculated by the
econometric model applied T-test, F-test, Determinant of Coefficient (R2) and Durbin-Watson(DW).
RESULTS AND DISCUSSION
The impact of Thai agricultural export on the income of the Thai economy can be expressed as
equation (1) below:
ln (GDP)t = 𝛼̂ 0 + 𝛼̂ 1 ln (AgExport)t + 𝛼̂ 2 ln (GDP)t-1 + ε(1)Where (GDP)t = Gross Domestic Product at time t, (AgExport)t = Agricultural Export Productat time t, (GDP)t-1 = Gross Domestic Product at time t-1, and ε = the error term.
The statistical results calculated from equation (1) could be expressed in Table 1. According toTable 1, the impact of Thai agricultural export products on income expressed that increasing in
agricultural export by 1 percent led to an increase in income by 0.03 percent while increasing inlast year's income by 1 percent led to an increase in income by 0.826 percent.

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Table 1 The impact of the agricultural export product on income
Dependent Variable: Gross Domestic Product 𝑙𝑛(𝐺𝐷𝑃𝑡 )Independent variables
Constantln (AgExport)tln (GDP)t-1
F-statistic = 228.53**
D.W
1.86**
̂2𝑹
0.974

Estimated coefficient
2.294
0.030
0.826

T-value
21.32**
9.53**
9.01****Statistical significance at 99 percent
Source: Calculation

The impact of Thai agricultural export product on employment of Thai economy can be
expressed as eaquation (2) below:
ln (Employment)t = 𝛼̂ 0 + 𝛼̂ 1 ln (AgExport)t + 𝛼̂ 2 ln (AgExport)t-1 + 𝛼̂ 3 ln (GDP)t-1 + ε(2)Where (Employment)t = Employment at time t, (AgExport)t = Agricultural Product Export attime t, (AgExport)t-1 = Agricultural Product Export at time t-1, (GDP)t-1 = Gross Domestic Productat time t-1, and ε = the error term.
The statistical results calculated from equation (1) could be expressed as Table 2 below:
Table 2 The impact of agricultural export product on employment
Independent variables
Constantln (AgExport)tln (AgExport)t-1
ln (GDP)t-1
F-statistic = 229.10**
D.W
1.82**
2
̂
𝑹
0.824

Dependent variable: 𝑙𝑛(𝐸𝑚𝑝𝑙𝑜𝑦𝑚𝑒𝑛𝑡𝑡 )Estimated coefficient
T-value
20.68
26.65**
0.36
18.68**
0.04
13.69**
0.14
21.80****Statistical significance at 99 percent
Source: Calculation

According to Table 2, the impact of Thai agricultural export product on employment
expressed that increasing in agricultural export product at time t by 1 percent led to an increase inemployment at time t by 0.36 percent, the increasing in agricultural export product at time t-1 by 1
percent led to an increasing in employment at time t by 0.04 percent while increasing in Gross
Domestic Product at time t-1 led to an increase in employment at time t by 0.14 percent.
CONCLUSION
Agricultural export products of Thailand have been an important sector for the Thai economy as
one of the economic drivers. From 1998 to 2017, the value of Thai agricultural export products has
significantly increased with an average of $23,819 Million and an average growth rate of 6.08
percent a year. For Thai Agricultural export product value forecasting, it is found that the average
growth rate is 9.16 percent a year. The agricultural export product also has an impact on income
and employment for the Thai economy, increasing in 1 percent of agricultural export-led to anincrease in income and employment by 0.03 and 0.36 percent, respectively.
Due to the research results, the agricultural sector has been and still is an important economic
sector of the Thai economy. Agricultural product export is one of the economic sectors thatfunctioned as an economic driver in the Thai economy, not only being the source of income but
also the source of employment for the Thai economy. In addition, the agricultural sector is still theⒸ ISERD

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source of food, clothes, raw materials, and labor to serve other sectors such as industrial, service,and other sectors in the Thai economy
ACKNOWLEDGEMENT
I, personally, thank Sukhothai Thammathirat Open University for research funding. I extended mymillion thanks to my beloved father and mother for their unconditional love. Special thanks to myfamily “Wittayakorn-Puripunpinyoo” with all my respect, love and heart.
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Brazil, L.T. and Bukenya, J.O. 2010. The impact of agricultural growth on rural non-farm income andemployment in Alabama. Retrieved from http://ageconsearch.umn.edu/bitstream/56482/2/SAEA_
StudentPaper_BraziL2[Final].pdf
Business Research Center, Kelley School of Business, Indiana University. 2012. Cultivating trade: The
economic impact of Indiana’s agricultural exports. Retrieved from http://www.ibrc.indiana.edu/studies/
CultivatingTrade2012.pdf
Central of Intelligence Agency. 2016. Export partner of Thailand. U.S. Government Printing Office,Retrieved from https://www.cia.gov/news-information
Central of Intelligence Agency. 2016. Import partner of Thailand. U.S. Government Printing Office,Retrieved from https://www.cia.gov/news-information
Ekanayake, M. 2012. Exports and economic growth in Asian developing countries: Cointegration and errorcorrection models e.m. Journal of Development Economics, 15 (2), 24-36.
Fechter, J. 2012. Agriculture and employment. Retrieved from https://www.kfw-entwicklungsbank.de/
Download-Center/PDF-Dokumente-Positionspapiere/ 2012_08_ Agriculture_ Emploment.pdf
Guido, G. Porto. 2005. Agricultural exports, Wages and unemployment. Development Research Group theWorld Bank, Retrieved from http://siteresources.worldbank.org/DEC/Resources/AgriculturalTrade
WagesUnemployment_G-Porto.pdf
Henri, M., Leturque, S. and Duncan, S. 2010. Thailand progress in agriculture: Transition and imposed after
EU’s warning. Cambridge University Press, London.
International Grain Council. 2014. Grain market report of 2013. Cambridge University Press, London.
International Monetary Fund. 2016. World economic outlook database. IMF Press, Washington.
Jaleel, A. and Harnhirun, S. 2012. Cointregration and causality between export and economic growth:
Evidence from the ASEAN countries. The Canadian Journal of Economics, 12 (4), 413-426.
Lefevre, A., Sawitta, A. and Thepgumpanat, P. 2015. Thai fisherman strike over new rules imposed after
EU’s warning. Cambridge University Press, London.
Mydans, M. and Seth, T. 2010. Waspa to flight Thai cassava plague. New York time, New York, USA.
Office of the National Economic and Social Development Board. 2016. The data of export and import ofThailand. The Royal Thai Government Printing Office, Retrieved from http://www.nesdb.go.th/main.
php?filename=QGDP_report Sustained Productivity Growth. Cambridge University Press, London.
Peter, C. 1997. Causality between export growth and industrial development: Empirical evidence from NICs.
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Soulé, G., Adjovi, E. and Aboudou, F. 2010. The impact on agricultural trade on employment in Beni, The
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Thai Custom Department. 2016. The data of export and import of Thailand. The Royal Thai Government,
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The Board of Investment of Thailand. 2016. The information of Thai investment. The Royal Thai
Government, Retrieved from http://www.boi.go.th/index.php? page=index& language=th
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go.th/index.php?page=index&language=th. 2016.
The Royal Thai Government. 2016. The data of export and import of Thailand. Thai Government Printing
Office, Retrieved from http:// www.bot.or.th/Thai/Pages/default.aspx. 2016.
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The Royal Thai Government. 2016. The data of growth domestic of Thailand. Thai Government Printing
Office, Retrieved from http:// www.bot.or.th/Thai/Pages/default.aspx
The World Factbook. 2016. Country comparison, Stock of direct foreign investment. U.S. Government
Printing Office, Retrieved from https://www.cia.gov/library/publications/the-world-factbook
William, T. 1997. Growth and export expansion in developing countries: Some empirical evidence. Journalof Development Economics, 12 (4), 121-130.
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World Bank. 2016. Thailand’s annual infrastructure report 2016. U.S. Government Printing Office, Retrieved
from https://www.cia.gov/library/publications/the-world-factbookⒸ ISERD

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Research article
erdComparative Study on Pulse Production with Different
Practices: A Case Study of Mungbean and Black Gram
KHIN MAR OO*
Yezin Agricultural University, Myanmar
Email: khinmaroo06@gmail.com

HTAY HTAY OO
Yezin Agricultural University, Myanmar

NYEIN NYEIN HTWE
Yezin Agricultural University, Myanmar

HLA THAN
Yezin Agricultural University, Myanmar
Received 15 December 2018

Accepted 20 October 2019(*Corresponding Author)

Abstract Pulses play a vital role in contributing to food security and enhancing soil fertility.
In Myanmar, pulses are the second most important crop after rice, and have a high potential
for export. Mungbean (Vigna radiata L.) and black gram (Vigna mungo L.) are the major
species of pulses that are widely grown throughout the country. The actual yield obtained at
the farm level is still lower than the potential yield and pulse farmers are facing various
problems and constraints. Considerable improvements of crop management practices areneeded in pulse cultivation. Field experiments were conducted at Thongwa Township(lower Myanmar) and Pyinmana Township (middle Myanmar) from November 2017 toMarch 2018 to investigate the effect of crop management practices on yield and suitabilityof mungbean and black gram varieties grown in the study areas. Each experimental area
was laid out in a split-plot design with four replications. Two crop management practices(Recommended practice and Farmers’ actual practice) were assigned to each main plot andfour varieties of mungbean (Yezin-1, Yezin-9, Yezin-11 and Yezin-14) were planted at theThongwa Township sites and black gram (Yezin-2, Yezin-5, Yezin-6 and Yezin-7) at the
Pyinmana Township site, being assigned to sub plots. The results reveal that more yield andyield components were obtained in mungbean varieties grown following recommended
practices than by farmers’ practices. However, the yield and yield components of black
gram varieties are not significantly different between the two crop management practices.
All mungbean varieties tested, except Yezin-11, are suitable for cultivation in Thongwa
Township. Of the black gram varieties tested in Pyinmana Township, only Yezin-7 isunsuitable. Therefore, it is necessary to further investigate and possibly amend therecommended practices for these particular areas to improve the production of mungbean
and black gram in these areas. In addition, demonstration plots that make use of theserecommended practices should be organized to improve the awareness of farmers of theadvantages of these techniques.
Keywords recommended practices, farmers’ practices, mungbean, black gram, yield

INTRODUCTION
Pulses play a vital role in their contribution to food security and enhancement of soil fertility. Their
inclusion as part of cereal-based cropping systems improves soil health by enriching organic
nitrogen, reducing the demand for the application of chemical fertilizers, and increasing soil micro
flora (Dasgupta and Roy, 2016). In Myanmar, pulses are the second most important crop and havea high export potential. Currently, about 4.2 million ha is planted to pulses, with yields in 2016Ⓒ ISERD97

IJERD – International Journal of Environmental and Rural Development (2019) 10-2

2017 ranging from 0.7 to 1.3 metric tons per hectare (GAIN, 2017). In Myanmar, black gram,
mungbean, pigeon pea, chickpea, cow pea, red kidney bean, velvet bean, and soybean are mostly
grown (Soe and Kyaw, 2016). Because of their export potential, mungbean (Vigna radiata L.) andblack gram (Vigna mungo L.) are widely sown as a second crop after monsoon rice in areas where
soil residual moisture is adequate for pulses.
The potential yields for mungbean and black gram determined by the Department ofAgricultural Research (DAR, 2016) are approximately 1.6 - 2.0-ton ha-1 and 1.6 - 3.2-ton ha-1,
respectively. However, the actual yield obtained at the farm level is lower than this and pulse
farmers face various problems and constraints, which result in a yield gap exists between farmers’
actual yields and potential yields. In order to enhance and sustain pulse productivity closer topotential, considerable improvements in crop management practices are necessary.
Some of the factors responsible for the low yields are the poor preparation of soil prior tosowing, the unbalanced use of fertilizers and ineffective practices used to protect growing plants(Bakoriya, 2015). An improved package of crop management practices, including ensuring thetimely availability of all inputs and more efficient application of these would enhance not only
productivity, nutritional quality and profitability but also environmental and social sustainability.
Timely sowing, regular weeding, effective and staged control of pests and diseases and better
harvesting methods could all play a part the development of a viable strategy.
OBJECTIVES
The objective of this research is to investigate the effect of crop management practices on yield andto determine the most suitable varieties of mungbean and black gram to cultivate in the study areas.
METHODOLOGY
Study Site
The growing period for mungbean and black gram as a second crop after the monsoon rice harvestis short, and the study sites selected are in Yangon Region and Nay Pyi Taw Union Territory whereresidual soil moisture conditions allow these pulse crops to be widely grown. Field experiments
were conducted at Nankale Village, Thongwa Township, Yangon Region which lies between
16°73‘01''- 1674'68'' N and 9656'08''- 9657'87'' E and Kyee Inn Village, Pyinmana Township,
Nay Pyi Taw Union Territory which lies between 1970'66''- 1972'62'' N and 9622'43''- 9625'73''
E from November to March during 2017 and 2018 (Fig. 1).
Pyinmana
TownshipPyinmana
Township

Kyee Inn Village
Kyee
VillageThongwa Township

Nankale Village

Fig. 1 Study areas at Nankale Village, Thongwa Township and Kyee Inn Village,
Pyinmana Township, MyanmarⒸ ISERD

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Experimental Design
Each experimental area was laid out in a split-plot design with four replications. Two crop
management practices (Recommended practice and Farmers’ actual practice) were employed on
the cultivation of four varieties of mungbean (Yezin-1, Yezin-9, Yezin-11 and Yezin-14) atThongwa Township and four of black gram (Yezin-2, Yezin-5, Yezin-6 and Yezin-7) at Pyinmana
Township in sub plots. The total area of each sub plot was 25m2 and these were 1m apart.
Crop Management Practices
The package of DOA recommended practices and the farmers’ actual practices commonly used in
the study areas were followed as crop management practices in main plot for each experimental
variety (Table 1) and (Table 2).
Table 1 DOA recommended practices and Farmers’ practices for mungbean cultivation
Factors
Land preparation
Sowing time
Variety used
Sowing method
Seed treatment
Weed management
Basal fertilizer used

Foliar fertilizer used
Pesticide used
Fungicide used

Recommended practices
Plowing - 1 time
Harrowing - 2 times
October - November
Yezin - 1
Line sowing - 30 to 40 kg ha-1
Broadcast - 60 kg ha-1
Seed treatment with fungicide
Weeding as necessary
Urea 50 kg ha-1, Triple super phosphate 125kg ha-1, Potash 60 kg ha-1, Gypsum 125 kg
ha-1
4 times for the whole season
As necessary based on scouting
As necessary

Farmers’ practices
Plowing - No
Harrowing - 3 times
November - December
Yezin -1, Yezin - 9, Yezin - 14
Broadcast - 60 kg ha-1
Not practiced
No weeding
Basal - Urea 60 kg ha-1,T super 60
kg ha-1
2-12 times for the whole season
2-12 times for the whole season
1-3 times for the whole season

Table 2 DOA recommended practices and Farmers’ practices for black gram cultivation
Factors
Land preparation
Sowing time
Variety used
Sowing method
Seed treatment
Weed management
Basal fertilizer used

Foliar fertilizer used
Pesticide used
Fungicide used

Recommended practices

Farmers’ practices

Plowing - 1 time
Harrowing - 2 times
October - November
Yezin - 6
Line sowing - 30 to 40 kg ha-1
Broadcast - 60 kg ha-1
Seed treatment with fungicide

Plowing - No
Harrowing - 2 times
November - December
Yezin -2, Yezin - 5, Yezin - 6

Weeding as necessary
Urea 50 kg ha-1, Triple super phosphate
125 kg ha-1, Potash 60 kg ha-1, Gypsum
125 kg ha-1
4 times for the whole season
As necessary based on scouting
As necessary

No weeding
Basal - Not practicedⒸ ISERD

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Broadcast - 60 kg ha-1
Not practiced

2-12 times for the whole season
2-12 times for the whole season
1-4 times for the whole season

IJERD – International Journal of Environmental and Rural Development (2019) 10-2

Data Collection
Two sites, each of 1 m2 were sampled randomly from each plot at harvest time and plant population(m-2) was determined. Using five tagged sample plants from each plot the number of pods plant -1
and yield (g plant-1) was recorded. The 100 seeds weight (g) per plot was also recorded.
Economic Analysis
Total cost of production incurred to economic returns from the crop, Gross monetary return, Netmonetary return and Benefit Cost ratio were calculated (Cimmyt and Cimmyt, 1988).
B : C ratio = Net monetary returns (MMK ha-1) / Cost of cultivation (MMK ha-1)
Statistical Analysis
All relevant data were subjected by using the Statistix 8 program and sample mean comparisonswere computed using Least Significant Difference (LSD) at 5% level.
RESULTS AND DISCUSSION
Plant Population (m-2)
Plant population (m-2) at harvest shows statistically significant differences for the crop management
practices applied to the pulse varieties tested in both study areas (Table 3 and Table 4). Because of
the broadcast sowing method farmers’ practice, plant population at harvest may be greater thanareas where was sown usint the recommended line sowing method. Although plant population (m-2)
for the mungbean varieties tested was not affected by crop management practices, significant
differences occurred for black gram varieties tested.
Table 3 Yield and yield components of mungbean at Thongwa Township
Treatments
Practices (A)GAP
Farmers’ practices
LSD0.05
Variety (B)Yezin-1
Yezin-9
Yezin-11
Yezin-14
LSD0.05
Main
Sub
Practices  Variety
CV% (a)CV% (b)

Plant m-2

Pods plant-1

100 Seed weight (g)Yield plant-1 (g)

33 b
48 a
4.2

14.81 a11.69 b2.37

5.55 a5.24 b
0.04

3.62 a2.48 b
0.62

44 a
44 a
43 a
28 b
3.2
**
**
ns
9.40
7.68

13.87 a12.50 a12.25 a14.37 a
2.49
*
ns
ns
15.94
17.89

5.17 c5.84 a5.22 bc
5.35 b
0.17
**
**
ns
0.61
3.08

3.17 ab2.89 bc
2.34 c3.81 a
0.48
*
**
ns
22.54
20.90

There was a statistically significant difference for the number of pods plant -1 depending oncrop management practices for mungbean, however, not so for black gram (Table 3 and Table 4).
Perhaps aeration among mungbean plants in line sowing may induce the bearing of more pods
plant-1 than broadcast sowing. Although the number of pods plant-1 showed no significant
difference for the pulse varieties tested, the Yezin-6 black gram variety attained the highest numberⒸ ISERD

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2of pods plant-1 (Fig. 2b). Also, the number of pods plant-1 for the tested major pulse varieties crop
were not affected by the different management practices.
Number of Pods Plant-1
(b)

(a)

Fig. 2 Effect of recommended practices (RP) and farmers’ practices (FP) on yieldand yield components of (a) mungbean and (b) black gram
100 Seeds Weight (g)There was a statistically significant difference for 100 seeds weight for the mungbean varieties
tested as a result of different crop management practices (Table 3). Consistent with the varietal
characteristic of Yezin-9, the highest 100 seeds weight was recorded for this strain (Fig. 2a).
Though the 100 seeds weight among black gram varieties did show significantly difference, Yezin6 exhibited the lowest 100 seeds weight (Fig. 2b).
Table 4 Yield and yield components of black gram at Pyinmana Township
Treatments
Practices (A)GAP
Farmers’ practices
LSD0.05
Variety (B)Yezin-2
Yezin-5
Yezin-6
Yezin-7
LSD0.05
Main
Sub
Practices  Variety
CV% (a)CV% (b)

Plant m-2

Pods plant-1

100 Seed weight (g)Yield plant-1 (g)

31 b
57 a
4.4

15.56 a12.94 a5.21

5.28 a5.00 a0.66

2.63 a1.85 a
0.91

47 a
45 a
45 a
39 b
5.3
**
*
*
8.86
11.46

14.50 ab14.62 ab16.25 a11.62 b
3.90
ns
ns
ns
32.51
26.08

5.46 a5.16 ab4.90 b
5.05 ab
0.51
ns
ns
ns
11.43
9.43

2.18 a2.18 a2.51 a2.09 a
0.43
ns
ns
ns
36.15
18.40

Yield Plant-1 (g)For the mungbean varieties, yield plant-1 (g) there was a statistically significant difference
according to crop management practice employed (Table 3). Mungbean variety of Yezin-14
attained the highest yield plant-1 (g) and the lowest was recorded in Yezin-11. On the contrary,
although there was no significant difference observed for black gram varieties tested under
different crop management practices, the lowest yield plant -1 (g) was observed for farmers’Ⓒ ISERD

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practices (Table 4). It is evident that plant population at harvest has a significant effect on pods
plant-1, seed weight and yield plant-1 for both mungbean and black gram varieties tested in the study(Table 5).
Table 5 Correlation between crop management practices and yield components of mungbean
and black gram
Green gramPlant
population

Pods plant-1
Seed weight
Yield plant-1- 0.531 **- 0.283- 0.643 **Pods
plant-1
0.119
0.345

seeds
weight0.045Black gramPlant
population

Pods
plant-1

seeds
weightPods plant-1
Seed weight
Yield plant-1- 0.237- 0.200- 0.671 **0.438 *
- 0.093- 0.254

Economic Analysis
Table 6 reveals that a higher benefit cost ratio (B:C) of 1.16 and 0.90 were recorded for mungbean
and black gram production respectively, using farmers’ practices. Because of the lower market
price of black gram compared to that of mungbean, black gram production has the lower benefit
cost ratio. The results clearly indicate that the market price of the crops significantly influence thenet monetary returns for farmers.
Table 6 Effect of crop management practices on economic of mungbean and black gram
(MMK ha-1)
Cost of cultivation
Gross monetary return
Net monetary return
Benefit cost ratio (B:C)

Mungbean
Recommended
Farmers’practices
practices
643,900
562’100
1,155,000
1,216,875
511,100
654;775
0.79
1.16Black gram
Recommended
Farmers’practices
practices606,400
411,250
631,250
781,250
24,850370,000
0.04
0.90

CONCLUSION
On the basis of the findings of one-year field investigation for both study areas, it can be concluded
that more yield (g plant-1) was obtained for mungbean varieties grown according to recommended
practices than those grown using farmers’ practices. In contrast, there was no significant difference
for black gram varieties grown under different crop management practices. Moreover, thesignificant effect of plant population (m-2) at harvest, on yield (g plan-1) for both mungbean andblack gram varieties, under both recommended and farmers’ practices should be considered not
only to increase productivity of pulse production but also increase net monetary returns of farmers.
All mungbean varieties tested except Yezin-11 were suitable in Thongwa Township. Of thoseblack gram varieties tested, Yezin-7 was not suitable for cultivation in Pyinmana Township.
Therefore, it is necessary to investigate the recommended practices for a particular area to sustain
the production of particular varieties of mungbean and black gram in that area. In addition,
demonstration plots that are location-specific should be cultivated to improve farmers knowledge.
ACKNOWLEDGEMENTS
The authors would like to thank the generous financial and technical training support of Japan
International Cooperation Agency (JICA) Project for Capacity Development of Yezin Agricultural
University. We also gratefully acknowledge Chief Advisor Professor Dr. Tanaka Koji and Dr.
Yoshinori Yamamoto for their generous technical and intellectual support and valuableⒸ ISERD

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involvement in this study. We are also appreciative to the authorized persons from Department ofAgriculture (DoA) and Department of Agricultural Research (DAR) for data provision.
REFERENCES
Bakoriya, L.L. 2015. Effect of different agronomic management practices on growth, development and yieldof summer mungbean (Vigna radiata L.) Wilczek, Master Thesis, Department of Agronomy, College ofAgriculture, Tikamgarh, 472 001, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Madhya Pradesh, 92.
Cimmyt, M. and Cimmyt, M. 1988. From agronomic data to farmer recommendations: An economics
training manual. CIMMYT.
Dasgupta, S. and Roy, I. 2016. Proceedings of the Regional Consultation on the Promotion of Pulses in Asia
for Multiple Health Benefits, Bangkok, Thailand, RAP Publication (FAO) eng no. 2015/05.
Department of Agricultural Research (DAR). 2016. Official recommendation on yield characters and cultural
practices of high yielding mungbean (Vigna radiata L.) and black gram (Vigna mungo L.), Ministry ofAgriculture, Livestock and Irrigation (MOALI), Union of Myanmar.
Global Agricultural Information Network (GAIN). 2017. Burma - Union of grain and feed annual, Grain
Report Number, BM 7003, USDA Foreign Agricultural Service, USA.
Soe Lin. and Kyaw Swar Win. 2016. Recent achievement in research and development of pulses in Myanmar.
Retrieved from www.fao.org/3/a-i5395e.pdfⒸ ISERD

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Research article
erd

Determination of Physicochemical Properties andCharacterization of Soil from Gold Mining Areasof Kachin State, Myanmar
MOE TIN KHAING*
Department of Chemistry, Myitkyina University, Myitkyina, Myanmar
Email: moetin.khaing@gmail.com

HLA SAN WIN
Department of Chemistry, Myitkyina University, Myitkyina, Myanmar
Received 25 February 2019

Accepted 20 October 2019(*Corresponding Author)

Abstract This study revealed the determination of physicochemical parameters andcharacterization of mineral constituents of soils affected by the low-tech gold mining
communities in the vicinity of Myitkyina town. The multi-increment soil samples with four
replications were collected from two active mines (Location-1 and 2) and an abandoned
mine (Location-3) during the first week of January 2018. Soil samples were analyzed forparticle size distribution, pH, electrical conductivity, organic carbon, NH3-N, and available
phosphorus. Soluble salts of soil water extract were also examined by titration method.
Then characterizations of soil mineral constituents were investigated by advanced
spectroscopic techniques such as Fourier Transform Infrared Spectroscopy (FT-IR), Energy
Dispersive X-ray (EDX) and Scanning Electron Microscope (SEM). The result showed thatsoil sample from location-1 was loam sand and the other two soil samples were sandtextural class. Soil pH, electrical conductivity, organic carbon, and available phosphorus
were significantly different among the three gold mining areas whereas NH3-N content was
not different by the gold mining. There was a high soluble salt accumulation in all locations.
The highest soluble salt was Ca2+ followed by Mg2+. It was found that iron (Fe) contained
as the highest relative amount in the soil which could exist with gold altogether and thesecond largest amount was given by titanium (Ti).
Keywords physicochemical parameters, mineral, FT-IR, EDX and SEM

INTRODUCTION
Sand and gravel are produced economically from the bank and floodplains of river. Gold mining on
the sand body of these areas can cause the damage of water table and distribution of sand structure.
After taking some time, water way alters as a result of erosion and deposition of sand structure.
Too much extraction of sand and gravel from rivers, streams, floodplains and channels for theconstruction of civil development and gold mining effects the ecosystems and functions of natural
water resources. Most of water pollutants are closely related with the methods and machineries ofgold mining. Among the gold mining, sand and gravel mining becomes the most treat to sustain thenature of the river and its surrounding area. It is also regarded as the current global issue andgradually increased with the reduction of fisheries, recreation and the stability of river channels(Images Asia and Pan Kachin Development Society, 2004). Much work has been carried out toaccess the environmental impacts of sand and gravel (Ako et al., 2014; Enkhzaya et al., 2016;
Eludoyin et al., 2017). Artisanal mining is mainly based on the tools and manual activities byproduction small amounts of gold and minerals (Canaveslo, 2014). Informal procedure of gold
mining associated hazardous water place, land structure degradation and contamination with heavy
toxic minerals (Emel et al., 2011).
The research reported an investigation on the physical and chemical characteristics of soil
from three riverbank gold mine sites near to Myitkyina Township (Fig. 1). Hydraulic mining andⒸ ISERD

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traditional panning techniques were observed in the study site for Location-1. Placer mining andtraditional panning methods were applied in the Location-2. The selected study site for Location-3
was on abandoned mine area. There was a comparison between the characteristics of soil from two
active mines, and those of abandoned mine. Lode gold districts in Myanmar are presented in Table 1.

Fig. 1 Location map of study sites
Table 1 Lode gold districts in Myanmar
District

Setting

Type

Age

Wuntho and Mabein

Magmatic arc

Mesothermal veins

Daungyu-Monywa andPegu Yoma

Magmatic arc and oldback

Kyaukpahto-Gegalaw

Sagaing Fault

Sediment-hosted epithermal
Au (As, Sb, Zn)
Sediment-hosted
Au (Sb, As)

Phayaung TaungKyaikto

Proterozoic-state belt

ThabyuFold-thrust belt

Shante and Pyinmana

Medial metamorphic
belt

Sediment-hosted Sb(Au, As)
Mesothermal (Au, Zn, Pb
and Au)Putao-Taungkamauk

Wuntho arc segment

High sulphidation Au(Cu)

MioceneMt Victoria-Kawlum

E Chin Hills antiform

Listwaenite Au

Upper CretaceousPaleocene

Sandstone-hosted Au(Cu)Latest Cretaceous
MioceneLate Eocene to
MioceneJurassic to
Paleocene
Post-Jurassic
Post-Cretaceous

OBJECTIVES
The objective of this research was to determine physicochemical properties of soils affected byartisanal gold mining areas on the Irrawaddy riverbank in the vicinity of Myitkyina, Myanmar.
METHODOLOGY
Study Area
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All selected artisanal gold mines in the vicinity of Myitkyina town to study for this research weresituated on the Irrawaddy riverbank and therefore only sub-soil samples within two to six feet werecollected. Soil samples were collected from Makawnyan (Latitude 25° 27.31' N and Longitude 97°
26.639' E) (designated as Location-1), Labanrosana (Latitude 25° 28.492' N and Longitude 97°27.231' E) (designated as Location-2) and Thida-Aye (Latitude 25° 25.009' N and Longitude 97°25.144' E) (designated as Location-3) as shown in Fig 2, 3, and 4, respectively.

Fig. 2 Location-1

Fig. 3 Location-2

Fig. 4 Location-3

Preparation of Multi-increment Soil Samples and Analysis
The individual soil increment collected was spaced out across each gold mining location as shownin Fig. 5. Ten individual soil samples or “increments” collected from each location were combinedin one container to make up a multi-increment soil sample. Two other soil increments were also
combined into two separate sample containers. Ten multi-increment soil samples were collectedfrom each location during the first week of January, 2018. Then, the soil samples were allowed toair dry. Large lumps were broken up by hand and then the soil was ground by milling with awooden roller. After grinding, the soil was screened through a 2 mm (10 meshes) sieve. The pH
was measured by a pH meter. The electrical conductivity (EC) of the soil sample was determinedelectrometrically with a calibrated electrical conductivity meter. Determination of texture ofcollected soil sample was done by a Hydrometer method.
Individual soil increment
Sample area boundaries

Fig. 5 Example with approximate locations of ten soil sample increments
spread across the specific sample area
The determination of ammonia nitrogen (NH3-N) and available phosphorus were done byalkaline permanganate method and Truog’s method, respectively. Total organic matter contents inthe soil samples were determined by titrimetric method at Soil Science Section, Department
Agricultural Research, Yezin, NayPyiTaw. The determination of soluble salts such as calcium(Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), carbonate (CO32-), bicarbonate (HCO3-),
sulphate (SO42-) and chloride (Cl-) were measured by titration method at the Soil Survey Section,
Irrigation Department, Yangon.
The characterization of soil mineral constituents such as iron (Fe), titanium (Ti), calcium (Ca),zirconium (Zr), manganese (Mn), potassium (K), chromium (Cr), vanadium (V), yttrium (Y),strontium (Sr), niobium (Nb), silicon (Si) and gold (Au) and morphological structures were
investigated by advanced spectroscopic techniques such as Fourier Transform Infrared
Spectroscopy (FT-IR), Energy Dispersive X-ray (EDX) and Scanning Electron Microscope (SEM)
at the Applied Geology Department, Yangon.

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Statistical Analysis
Differences among the three gold mining locations were analyzed by one-way analysis of variancefor each parameter and mean comparison among them were compared by least significant different(LSD) method at 5% level. All data analysis was done using STAR software and Microsoft Excel
program (2010).
RESULTS AND DISCUSSION
Soil Physicochemical Properties in Gold Mining Areas
In textural analysis, it was found that soil from Location-1 was loam sand textural class while othertwo soil samples from Location-2 and 3 were sand class (Table 2). All soil samples showed similar
pH values and nearly neutral in all locations (Table 3). Among all soil samples, Location-1 had low
electrical conductivity (25.00 µmhos/cm) than Location-2 (32.80 µmhos/cm) and Location-3(31.10 µmhos/cm).
NH3-N, available phosphorus and organic matter contents were found in Table 4. All soil
samples showed similar NH3-N contents in all locations as indicating that there was no significant
different among three gold mines. Location-1 gave the high available P and soil organic matter
contents than others Location-2 and 3.
Table 2 Textural analysis in three gold mining areas
Location
Location-1
Location-2
Location-3

Sand (%)
75
89
89

Silt (%)
129
9Composition
Clay (%)
13
2
2

Texture class
Loam sand
Sand
Sand

Table 3 Physicochemical properties in three gold mining areas (mean±S.E., n=4 per location)
Location
Location-1
Location-2
Location-3pH
7.43 ±0.03 a
7.25 ±0.03 b
7.30 ±0.04 b

EC (µmhos/cm)
25.00 ±0.13 c
32.80 ±0.36 a
31.10 ±0.39 b

Color
Yellow
Grey
Grey

Mean values followed by different letters in the same column are not significantly different at 5% level by the LSD test

Table 4 Chemical properties in three gold mining areas (mean±S.E., n=4 per location)
Location
Location-1
Location-2
Location-3

NH3-N ( ppm )6.39 ±0.01 a
6.39 ±0.01 a
6.37 ±0.01 a

Available P (ppm)
5.07 ±0.14 a
4.50 ±0.09 b
4.30 ±0.10 b

Organic matter (%)
0.71 ±0.02 a
0.55 ±0.01 b
0.52 ±0.02 b

Mean values followed by different letters in the same column are not significantly different at 5% level by the LSD test

Table 5 Soluble salt contents (cations) in the gold mining areas (mean±S.E., n=4 per location)
Location
Location-1
Location-2
Location-3

Na+
0.22 ±0.01 a
0.22 ±0.02 a
0.20 ±0.02 a

Ca2+

Mg2+

meq/100 g of soil
4.01 ±0.06 a
0.98 ±0.03 b
2.40 ±0.02 b
1.46 ±0.02 a
2.31 ±0.02 c
1.01 ±0.06 b

K+
0.10 ±0.01 b
0.05 ±0.01 c
0.12 ±0.01 a

Mean values followed by different letters in the same column are not significantly different at 5% level by the LSD test

There could be observed that a high soluble salts accumulation in all locations (Table 5 and 6).
Soil sample from Location-1 showed the highest soluble salt, Ca2+ with the amount of 4.01
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meq/100g of soil whereas the lowest SO42- with the amount of 0.011 meq/100g of soil among thetested soil samples. Similarly, Location-2 and Location-3 also showed that the highest Ca2+ withthe amount of 2.40 and 2.31 meq/100g of soil, respectively, while the lowest value of SO 42- wasfound with the amount of 0.011 meq/100g of soil.
Table 6 Soluble salt contents (anions) in the gold mining areas (mean±S.E., n=4 per location)
Location
Location-1
Location-2
Location-3

CO32Non-detectableNon-detectableNon-detectable

HCO3-

SO42-

meq/100 g of soil
0.60 ±0.009 a
0.011 ±0.003 b
0.40 ±0.013 b
0.011 ±0.003 a
0.41 ±0.011 b
0.011 ±0.003 b

Cl 0.18 ±0.020 a
0.09 ±0.010 b
0.09 ±0.011 b

Mean values followed by different letters in the same column are not significantly different at 5% level by the LSD test

Characterization of Soil Samples from Three Gold Mining Areas
Shwe-chi in Myanmar which was finally obtained by traditional panning method was applied forthe characterization of soil samples. All features appearing in the FT-IR spectral data pointed out avariety of Fe–O, Ti–O, Ca–O and Zn–O stretching and bending vibrations. According to EnergyDispersive X-ray spectral data, all soil samples gave the highest relative proportion of Fe mineral in(Table 7). It was followed by Ti and then Au had the lowest proportion among the mineral
constituents.
Table 7 Proportion of mineral constituents of soil sample in three gold mining areas
No.

Analyte metal

1
2
3
4
5
6
7
8
9
10
11
12
13

Fe
Ti
Ca
Zr
Mn
K
Cr
V
Y
Sr
Nb
Si
Au

Location-1

Location-2
Per cent
84.325
6.977
3.860
2.371
0.957

77.040
7.590
3.707
1.498
0.965
0.528
0.412
0.373
0.172
0.077
0.058
7.579
0.001

0.504
0.358
0.330
0.130
0.131
0.058
-

Location-3
86.700
7.163
2.811
1.028
1.192
0.347
0.232
0.354
0.058
0.113
0.001

The SEM microimage (Fig. 6) showed that the minerals were composed mostly of aggregateswith sizes generally within 5 µm and indicated homogeneous distribution of granules throughout
soil sample in Location-1. The SEM microimages also showed that the surface soils from different
locations indicated that the minerals in these soil samples were composed of aggregates of different
particles as given in the figures of Location-2 and 3 (Fig. 6) with no specific regular morphologicalstructure. SEM micro-images indicated clearly the different soil morphologies between the loam
sand and sand textural classes.
According to EDX analysis on three soil samples, Fe showed its highest relative amounts of(77.040%, 84.325% and 86.700%) and it was followed by the amount of Ti, (7.590%, 6.977% and7.163%) respectively. Ca and Zr composed together with intermediate amount and K, Cr, V, Y, Sr,
Nb and Au minerals were observed as the lowest constituents of these soil samples.
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Location-1

Location-2

Location-3

Fig. 6 SEM micro-images of Locaton-1, 2 and 3
CONCLUSION
According to the analyses of this study, riverbank sand mining can cause not only physicalproperties such as pH, EC, color and texture and destruction of the original landscape of the area
and collapse of riverbank but also chemical effects like water pollution with many mineralcontaminants from mine running off into river water and wetlands.
ACKNOWLEDGEMENTS
I owe a great deal of gratitude to Dr Aung Win, Rector, Dr Aye Aye Ko and Dr Soe Myint Aye,
Pro-rectors, University of Myitkyina, Dr Ni Ni Aung, Professor and Head, Dr Htay Htay Win,
Professor, Department of Chemistry, University of Myitkyina for their invaluable advices, kind
guidance and encouragements for this research work.
REFERENCES
Ako, T.A., Onoduku, U.S., Oke, S.A., Essien, B.I., Idris, F.N. and Ahmed, A.A. 2014. Environmental effectsof sand and gravel mining on land and soil in Luku, Minna, Niger State, North Central Nigeria. Journal of
Geosciences and Geomatics, 2 (2), 42-49.
Canaveslo, R. 2014. Formal mining investments and artisanal mining in southern Madagascar: Effects of
spontaneous reactions and adjustment polices on poverty alleviation. Land Use Policy, 36, 145-154.
Eludoyin, A.O., Ojo, A.T., Ojo, T.O. and Awotoye, O.O. 2017. Effect of artisanal gold mining activities on
soil properties in a part of southwestern Nigeria. Cogent Environmental Science, 3 (1).
Emel, J., Huber, M.T. and Makene, M.H. 2011. Extracting sovereignty: Capital, territory, and gold mining in
Tianzania. Polotical Geography, 30, 70-79.
Enkhzaya, S., Ohe , K., Shiomori, K., Oyuntsetseq, B., Bayanjorgal, O. and Watanable, M. 2016. Assessmentof heavy metal in mining tailing around Boroo and Zuunkharaa gold mining areas of Mongolia. Journalof Environmental Science and Technology, 9 (5), 379-389.
Images Asia and Pan Kachin Development Society. 2004. At what price, gold mining in Kachin State,
Burma.

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Research article
erd

Functional Evaluation of Groundwater Level Decrease inNon-sloped Subsurface Drainage Systems in Upland Field
on Peatland
NAHO NOHARA
Graduate School of Agriculture, Hokkaido University, Sapporo, JapanMINORU YOKOCHI
Graduate School of Global Food Resources, Hokkaido University, Sapporo, JapanTADAO YAMAMOTO*
Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan
Email: tady@env.agr.hokudai.ac.jp

TAKASHI INOUE
Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan
Received 1 February 2019

Accepted 20 October 2019(*Corresponding Author)

Abstract In lowland farmland, the maintenance cost of conventional inclined subsurface
drainage systems is high because the drainage pipes must be laid at depth, or the tile
deepens as the farm field enlarges. To reduce the maintenance cost, the Hokkaido
Provincial Government of Japan has introduced a subsurface drainage system with asmaller inclination angle than the conventional method. However, the drainage effects of
non-sloped subsurface drainage systems have been rarely reported, and insufficientevidence has prevented their widespread acceptance. The present study investigates how theslope of the drainage pipe influences the groundwater-level decrease in poorly drained
fields. The survey was conducted in the upland field on peatland located in the Ishikari
River Basin, Hokkaido. In 2015, two types of subsurface drainage systems were constructedin the same lot: a conventional subsurface drainage (sloped area) system, and a subsurface
drainage system with low inclination (non-sloped area). After measuring the groundwaterlevel at 12 points and the precipitation from 2016 to 2017, we found that: i) the
groundwater level was higher in the non-sloped area than in the sloped area, ii) between
2016 and 2017, the groundwater level decreased in the sloped area and rose in the nonsloped area. The above results suggest that the efficiency of decreasing the groundwaterlevel during 3 years after the construction was lower in non-sloped subsurface drainage thanin sloped subsurface drainage, which is different from that observed in the previous study.
Keywords subsurface drainage, groundwater level, large-scale field, peatland

INTRODUCTION
In some developed countries, including Japan, the economic growth of the agricultural industry has
declined while that of the secondary and tertiary industries has increased. This problem has
severely affected rural communities in Japan. Maintaining agricultural production and enhancing
the competitiveness of agriculture are urgent demands in Japan’s agricultural policy. As thefarming population decreases, agricultural production must be maintained by astute agriculturalbusiness, improvement of work efficiency, and labor-saving measures. As a precondition ofarresting this decline, the enlargement of farm fields has been promoted. Subsurface drainage has
been widely implemented for improving the yield and quality of farm products. In the future, thecompetitiveness of agriculture must be bolstered by lowering the installation cost of facilities andconstructing irrigation and drainage systems, including subsurface drainage systems.
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In Hokkaido, northern Japan, lowland farmlands developed from peatland are widespread, andsubsurface drainage is employed to improve the soil condition. Recently, the average field size has
progressively enlarged to enhance the productivity. Deeper pipes and ditches are needed to installconventionally sloped subsurface drainage pipes in large fields, which increases theimplementation cost. In an attempt to alleviate this problem, subsurface drainage pipes with no
inclination (<1/600) have been trialed in a suitable geographical feature (Koshiba et al., 2005).
However, as very few studies have evaluated the function of non-sloped subsurface drainage, thepracticality of this approach is currently unknown. Non-sloped subsurface drainage reduces overtime as the drainpipes become uneven and accumulate soil sediments. Koshiba et al. (2005)
reported no significant malfunction caused by pipe sedimentation and unevenness after five years’
implementation of non-sloped subsurface drainage in a farm field with sandy loam soil. They also
reported the same drainage through non-sloped and sloped pipes. They concluded that non-sloped
pipe drainage effectively reduces the installation cost (Koshiba et al., 2005).
However, the functioning of non-sloped subsurface drainage has not yet been investigated in
Hokkaido, where peat layer is distributed. Peat is an organic-rich soil consisting mainly of
undecomposed plant material, which accumulates in saturated environments. Such environments
require intense drainage to reach suitable conditions for agriculture, but owing to their uniquecomposition, inevitably subside under agricultural drainage and artificial loading. Armstrong andCastle (1999) stated that peat subsidence frequently misaligns the drainpipes and inverts thegradient along the pipes. They also mentioned that because peat is rich in iron, pipes laid inpeatland are often clogged with deposits of iron ochre, an orange-colored mud made of ironcompounds (Armstrong and Castle, 1999). The question remains whether non-sloped drainage
performs well in peatlands, where the drainage conditions are difficult. Therefore, to evaluate thefunction of non-sloped subsurface drainage on peatland fields, this study compares thegroundwater-level changes in conventional (sloped) and non-sloped pipe subsurface drainage
systems installed in the same field.
METHODOLOGY
Overview of the Research Site
The study was carried out in an upland field in Iwamizawa (43°12′ N, 141°43′E), located in the eastof the Ishikari plains in Hokkaido (Fig. 1). The mean annual temperature and precipitation are
7.6°C and 1,163 mm, respectively. In the research field, the peat layer underlies a 30 cm-thickupper artificial soil. In August of 2015, subsurface drainage pipes with low inclination were
installed in one-half of the field (forming the non-sloped area), and conventional subsurface
drainage was implemented in the other half (sloped area) (Fig. 2). This setup permits a performancecomparison between the drainage experiment and a control experiment with a different drainpipe
slope in the same lot. The field size is 1.1 ha, and onions were grown from May to August in 2016
and 2017. The drainpipes are buried 70 cm below the surface at 9-m intervals. In the sloped area,
the drainpipes are inclined at 1/500, and their diameter is 60 mm (versus 80 mm in the non-slopedarea). This difference in diameter is based on the design criteria. The drainpipes are filled withgravels. Prior to cultivation, the subsoil was broken to improve the drainage.
Survey Equipment
The precipitation in the field was measured hourly by a tipping-bucket rain gauge with a diameterof 20 cm (HOBO event, Climatec Incorporated, Tokyo, Japan) placed near the study field.
Groundwater-level gauges for absolute pressure measurements (S & DL water level, Oyo
Corporation, Tokyo, Japan) were set at six points (five between the drainpipes, and one just above
the drainpipe) in both the sloped and the non-sloped areas, giving 12 observation points in total(Fig. 2). The groundwater level was measured every 30 minutes. The measured absolute pressures
were converted to gauge pressures by a barometer installed near the field.
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Fig. 1 Location of the research site

Fig. 2 Overview of the research site

Evaluation Method
The groundwater level generally rises immediately after rainfall, and gradually declines after therain. The drop-down phase depends on the characteristics of the draining process. From theobtained rainfall data and the groundwater levels in the field investigations, we evaluated thefollowing contents: i) groundwater-level dynamics, ii) groundwater-level drop response after a
rainwater-induced rise in the groundwater level, and iii) achievement rate of the design target set by
Hokkaido Prefecture Agricultural Administration Department. The subsurface drainage efficiency
was evaluated by comparing the rainfall-related contents and groundwater table fluctuations in thesloped and non-sloped areas. We also evaluated the time-series changes in the function of eachdrainage system by comparing the results of 2016 and 2017. The observation data from June to
mid-August in 2016 and 2017 were used for the drainage evaluation. For determining the drainage
efficiency, we defined the following terms.
Groundwater level: Vertical distance from the ground surface to the groundwater table at eachobservation point.
Rain event: Rainfall within 24 hours of the rainfall start is regarded as a rainfall series. Rainfall of
1 mm/h or more within 24 hours after the rain stopped was included in the same event. Rain eventswith a total rainfall of 10 mm or more were used in the evaluation.
Amount of groundwater level increase: The groundwater-level difference between immediately
before the rain event and the highest water level during the rain event.
Amount of groundwater level drop: The groundwater-level difference between the highest waterlevel during the rain event and the lowest water level after the rain event.
Groundwater level drop rate: The ratio of the amount of groundwater level drop to the amount ofgroundwater-level rise after the rain event.
RESULTS AND DISCUSSION
Fluctuation of Groundwater Level
The drainage was evaluated by comparing the fluctuations in the groundwater levels at eachobservation point. The results are presented as box plots. Fig. 3 shows the distribution ofgroundwater levels at six observation points located at the same distance from the drainage ditch(N2, N5, N6, S2, S5, S6) in 2017. Comparing the fluctuations in groundwater levels in 2017, thefluctuation range of groundwater levels at N5 tended to be narrower than other points. The
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sloped area. Fig. 4 compares the distributions of groundwater level at the above-mentioned six
observation points in 2016 and 2017. The 2016 survey result confirmed the high performance ofthe non-sloped subsurface drainage relative to the sloped system, similar to previous studies (e.g.
Koshiba et.al., 2005). However, the groundwater distribution in the non-sloped area was higher in2017 than in 2016. In contrast, the groundwater in the sloped area was lower in 2017 than in 2016,
possibly because the subsoil was broken by subsoiler before tilling in 2017, and the precipitation
was lower in that year than in 2016. However, despite the same climate conditions and the same
farming method in both areas, subsoil breaking exerted no effect in the non-sloped area. Thissuggests that, for some reason, the subsurface drainage functioning (maintenance of low-levelgroundwater) was lower in the non-sloped area than in the sloped area.

The top and bottom extremes of the whiskers indicate the maximum and minimum groundwater levels, respectively, andthe segment inside the box is the median groundwater level. The lower and upper base lines of the boxes indicate the firstquartile (25th percentile) and third quartile (75th percentile), respectively.

Fig. 3 Groundwater level changes at
6 observation points in 2017

Fig. 4 Comparison of groundwater-level fluctuations
between 2016 and 2017 at 6 observation points

Rain Response of Groundwater Level
In a properly functioning drainage system, the raised groundwater table quickly falls after therainfall cessation. The drainage function was evaluated by relating the rises and falls in the
groundwater level after several rain events. The evaluation was performed at 10 observation points(N1, N2, N3, N5, N6, S1, S2, S3, S5, S6) located between the drainage pipes. Points located above
the drainage pipes (N4, S4) were excluded because their locations relative to the drainpipe differedfrom those of the other points. Figs. 5 and 6 plot the groundwater-level drop versus thegroundwater-level rise at 24 and 72 hours, respectively, at all observation points after each rain
event. The average groundwater-level drop rate over all rain events and observation points can be
determined from the regression coefficient; when the regression line is steep, the soil is welldrained after the rainfall-induced rise in groundwater level. The drainage efficiencies werecompared by comparing the steepness of the regression lines between the sloped and the nonsloped areas, or between 2016 and 2017. The statistical significances of the groundwater-level drop
rates were assessed by a 2-sample t-test at the 95% confidence level.
We first compared the drainages in the sloped and non-sloped areas in 2017. As shown in Fig.
5, the gradient of the regression line was smaller in the non-sloped area than in the sloped area. In
the sloped area, 67% of the groundwater level raised by rainfall (on average) was withdrawn within
24 hours, versus 52% in the non-sloped area. The groundwater-level drop rate was significantly
higher in the sloped than in the non-sloped area (2-sample t-test; p <0.01). At 72 hours following
the rain events, the groundwater drop rates were statistically the same (2-sample t-test; p >0.1). The
results imply that immediately after the rain events, the drainage system with sloped pipes better
withdrew the groundwater level than the drainage system with level pipes.
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Next, the time-series changes of drainage function in the non-sloped area were compared
between 2016 and 2017. At 24 hours following the rain events, the groundwater-level drop rate wassmaller in 2017 than in 2016, and the reduction was significant (2-sample t-test; p <0.01). The same
result was obtained at 72 hours following the rain events (Fig. 6). Specifically, the groundwater levelat 72 hours following the rain events dropped by 100% in 2016 (meaning that the groundwater level
had recovered to its pre-rain level within 72 hours), but reduced by only 82% in 2017. In the slopedarea, a reduction in the groundwater-level drop rate between 2016 and 2017 (from 96% to 85%) was
found only at 72 hours following the rain events. If it is assumed that there are no differences in soil
physical properties based on farming operations, the decline of the subsurface drainage function after
rainfall was more conspicuous in the non-sloped area than in the sloped area, implying that inclining
the drainpipes plays an important role in maintaining drainage function.

Fig. 5 Relationship between rise and fall ingroundwater level at 24 hours afterrain events in 2017

Fig. 6 Relationship between rise and fall ingroundwater level at 72 hours afterrain events in the non-sloped area

Achievement Rate of the Groundwater Level Standard
Table 1 Achievement rates of groundwater-level standard

Non-sloped
area

Sloped area

N1
N2
N3
N4
N5
N6
Avg.
S1
S2
S3
S4
S5
S6
Avg.

2016
100%
86%
100%
100%
100%
100%
97%
100%
43%
71%
100%
100%
86%
83%

2017
63%
38%
63%
－
100%
0%
53%
100%
63%
100%
100%
100%
100%
94%

The desired groundwater level has been set as a design target of subsurface drainage systems.
According to the Hokkaido Prefecture Agricultural Administration Department (2010), a wellⒸ ISERD114

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designed groundwater level should be −60 to −50 cm under dry conditions, and −50 to −40 cm at
two or three days after cessation of a rain event. However, during the observation period of thepresent study, the no-rainfall periods rarely continued for more than seven days; therefore, we
decided to set the standard for a well-functioning groundwater level below −40 cm at 72 hours after
cessation of a rain event. The achievement rate of this standard was calculated at each observation
point, and used in the drainage-efficiency evaluation. Table 1 lists the achievement rates at allobservation points in 2016 and 2017. The achievement rates and averages in the sloped area
improved from 2016 to 2017. On the other hand, many points in the non-sloped area showed low
achievement rates in 2017, and the average achievement rate was considerably decreased from thatof 2016 in spite of subsoil breakage. Furthermore, the achievement rate was higher in non-slope
area than in the sloped area in 2016; therefore, it seems that pipe inclination is not a direct cause of
the decrease in the subsurface drainage function. From these results, we considered that somefactors, except for soil physical changes, influencing drainage function decline may have occurredby the elapsed time since the construction. Thus, the cause of drainage function decline may berelated to changes in conditions inside the pipe, similar to water pass prevention due to sedimentaccumulation.
CONCLUSION
The present study investigated how the slope of the drainage pipe influences the groundwater-level
decrease in poorly drained fields on peatland located in the Ishikari River Basin, Hokkaido. Aftermeasuring the groundwater level at 12 points and the precipitation from 2016 to 2017, we found
that: (i) the groundwater level was higher in the non-sloped area than in the sloped area; (ii)between 2016 and 2017, the groundwater level decreased in the sloped area and increased in the
non-sloped area; and (iii) the drainage efficiency in the non-sloped area tended to decrease after 3
years of installation.
The 2017 findings revealed a large difference between the groundwater behavior in the sloped
and non-sloped areas, although the same farming method was implemented in both areas, and thedrainage function obviously declined in the non-sloped area. These results contradict a previous
field study conducted on loam soil (Koshiba et al., 2005). Unlike loam soil, peatlands cause special
problems in subsurface drainage, such as subsidence-associated misalignment of the pipes anddeposition of iron ochre (Thiobacillus ferrooxidans colony) in the pipe interiors. Subsurface
drainage through sloped pipes may tolerate these problems because the pipe gradient increases theflow velocity of the drainage water. At sufficiently high flow velocities, the deposit is easily
washed away. The gradient might also prevent misalignment and inverse gradients of the pipes. On
the other hand, the non-sloped drainage may be adversely affected by these peatland characteristics.
Our results implied that inclining or periodic cleaning the drainpipes is important for maintaining
the performance of the drainage system.
ACKNOWLEDGEMENTS
This research was conducted under the cooperation agreement between Hokkaido Prefecture
Agricultural Administration Department, and Fishers and Forest Department, andFaculty/Graduation School/Research Faculty of Agriculture, Hokkaido University. The authors
would like to thank the staffs of Hokkaido Prefecture Agricultural Administration Department andSorachi Subprefecture, and Central Agricultural Experiment Station of Hokkaido Research
Organization for their supports.
REFERENCES
Armstrong, A.C. and Castle, D.A. 1999. Drainage of organic soils. In Skaggs, R.W. and Schilfgaarde, J. van(Eds.) Agricultural Drainage, 1083-1105, Madison, Wisconsin, USA.
Hokkaido Prefecture Agricultural Administration Department. 2010. Design guidelines for subsurface drainage.
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33-34, Retrived from http://www.pref.hokkaido.lg.jp/ns/jcs/grp/03/ankyosisin2206.pdf
Koshiba, N., Okuyama, T., Iwabuchi, Y. and Arihara, K. 2005. Drainage performance of a shallow pipe drainwith no slope. Jour. JSIDRE, 73 (10), 917-918.

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Research article
erd

Identifying the Minimum Number of Observed Rainfall
Events Required for Optimal TOPMODEL Parameters in
Mid-sized Equatorial Catchments
EMMANUEL OKIRIA
Graduate School of Agriculture, Tokyo University of Agriculture, Tokyo, Japan

HIROMU OKAZAWA*
Faculty of Regional Environment Science, Tokyo University of Agriculture, Tokyo, Japan
Email: h1okazaw@nodai.ac.jp

YURI YAMAZAKI
Faculty of Regional Environment Science, Tokyo University of Agriculture, Tokyo, JapanYUKIMITSU KOBAYASHI
Graduate School of Agriculture, Tokyo University of Agriculture, Tokyo, JapanSHINJI SUZUKI
Faculty of Regional Environment Science, Tokyo University of Agriculture, Tokyo, Japan
Received 26 January 2019

Accepted 20 October 2019(*Corresponding Author)

Abstract TOPMODEL, a topography-based, semi-distributed hydrological model wasapplied to the 84 km2 Atari catchment in Eastern Uganda. The study sought to identify theminimum number of rainfall events needed to optimally calibrate 5 unknown parameters foryearly hydrological simulation. Model input data was daily averaged precipitation, riverdischarge and evapotranspiration for the year 2015 with the output being simulated
discharge. A rainfall event was defined as consecutive days of effective rainfall - effective
rainfall being a daily rainfall ≥ 5.0 mm. Parameterization was done for Sequentially
Accumulated Rainfall Events (SARE), beginning with 1 event and sequentially progressing
until all 54 observed rainfall events in the year were used. All SARE had similar starting
dates with the end dates being variable. The ‘true’ parameters were those derived from
inputting all observed rainfall events while the other instances of the parameters frompartial SARE were classified as ‘non-true’. Elimination criterion of ‘non-true’ parameters
was set at an error of ±30%. Parameter values varied with the change in number of rainfall
events, showing their dependence on rainfall characteristics. Downslope saturated
transmissivity (Te) and maximum root zone storage deficit (SRmax) were the most and least
variable from their means respectively. Also, exponential decay parameter (m) and delay
time constant (td) needed the least and the greatest number of rainfall events to stabilise
within the ±30% error bounds respectively. Therefore, the minimum number of rainfall
events required to calibrate TOPMODEL and to optimise td in mid-sized equatorial
catchments in Eastern Uganda are equivalent. Consequently, it required at least 49 rainfall
events to calibrate TOPMODEL in 2015.
Keywords calibrate, modelling, rainfall event, SARE, TOPMODELINTRODUCTION
Observed hydro-meteorological data are useful for irrigation and drainage planning. In areas thatlack this data, hydrological models are used to predict stream discharge. One such model is
TOPMODEL, a conceptual, semi-distributed hydrological model (Beven and Kirkby, 1979) thathas been used worldwide. In Africa, TOPMODEL was applied in a humid tropical climate inⒸ ISERD

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Nigeria (Campling et al., 2002) and in an Ethiopian catchment (Gumindoga et al., 2014). To date,
the authors have not found published evidence of the application of TOPMODEL in Uganda.
Generally, Uganda has a scarcity of hydro-meteorological data, and worse still, even theavailable data is of poor quality, e.g., temporal gaps, unreliability, and inaccuracy of rating curves.
Notably, most Ugandan rivers are ungauged, and bleaker still, only about 33% of installed waterlevel gauging stations are currently operational (MWE, 2013).
Given the challenges above, hydrological models could come in handy. But hydrologicalmodels need calibration, a process that requires the input of observed hydro-meteorological data.
For this reason, Atari catchment was chosen as a target site for the study. Unlike many catchmentsin Uganda, it is equipped with modern hydrological and meteorological monitoring facilities. The
TOPMODEL concept was thus applied to the Atari catchment located in Eastern Uganda.
According to Coles et al. (1997); (1) Rainfall intensity influences rainfall-runoff response of acatchment, and (2) Calibrated parameters are only relevant to the rainfall event(s) that was used fortheir calibration. From these findings, it would be ideal to use all possible permutations of rainfall
events to achieve representative parameters suitable for yearly hydrological simulations. However,given the previously mentioned observed data deficiencies in Uganda, it is necessary to haveinsight into the premise that limited observed data may be sufficient to calibrate model parameterswhich can be used for yearly hydrologic simulation. Therefore, the purpose of the study is to
identify the minimum number of rainfall events required for optimal yearly TOPMODEL
parameter calibration.
METHODOLOGY
Study Site
The study area is Atari, a headwater catchment of Mt. Elgon in Eastern Uganda, with a drainage
area of 84 km2 above the stream gauging station and a corresponding channel length of 33 km. Its
topography is comprised of mountainous areas from where the main stream (Atari River) originatesand flows to the relatively flat plains. From ASTER GDEM, the difference in height between thelowest and the highest point is 2,389 m. Of the 84 km2, 35 km2 (42%) is forest, 28 km2 (33%) is
agricultural area and 21 km2 (25%) is rangeland.

Fig. 3 Instrumentation and land use in Atari catchment
RG. Stn is rain gauge, WLG is water level gauge, Met. Stn is meteorological stationⒸ ISERD

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Under the Project on Irrigation Scheme Development in Central and Eastern Uganda (PISD)(JICA, 2017), hydro-meteorological monitoring equipment were set up in Atari catchment in 2015,
viz., a mid-stream rain-gauge to detect catchment rainfall, a downstream meteorological station tomeasure evapotranspiration parameters and a water level sensor at a control section of Atari River.
TOPMODEL
1) Description of TOPMODELTOPMODEL is a conceptual, semi-distributed model suggested by Beven and Kirkby (1979). It
divides the soil layer into root zone, unsaturated zone and saturated zone. The upper soil layers(root zone and unsaturated zone) are analysed at grid-scale as distributed models while the lower
layer (saturated zone) is computed as a catchment scale lumped model. TOPMODEL evaluates thestate of wetness of the surface layer of a basin from the Topographical Index (TI).
𝒂

𝑻𝑰 = 𝒍𝒏 𝐭𝐚𝐧𝒊𝜷(1)𝒊Where ai is upstream contributing area per unit contour length, tan βi is local slope and i is
grid number.
TI is derived from a Digital Elevation Model (DEM) and it spatially evaluates the amount of
surface flow. Details of TOPMODEL are in Mukae, et al. (2017) and Beven and Kirkby (1979).

Fig. 4 Histogram of TI distribution for Atari catchment
2) Computational Procedure of TOPMODEL
Input data is observed daily precipitation, observed river discharge, actual evapotranspiration (ETa)and a TI that is derived from 30 m grid DEM. Rainfall was measured for each event and otherhydro-meteorological parameters were recorded at 10-minute logging intervals, but the daily
averages were used for computation.
a. The water balance equation of the root zone:
The amount of water that is stored in the root zone is calculated from the water balance of rainfall[L], ETa [L], maximum storage deficit in the root zone (SRmax) [L] and storage deficit in the rootzone (SRZ) [L]. When SRZ < 0, the excess water (EXi) flows to the unsaturated zone (SUZi) [L].
Potential evapotranspiration (ET0) is calculated by the Penman-Monteith method (Allen et al.,1998). ETa is treated as a function of ET0, SRmax and SRZ.
𝑺𝑹𝒁𝒊

𝑬𝑻𝒂 = 𝑬𝑻𝟎 (𝑺𝑹

𝒎𝒂𝒙

)

(2)

b. The water balance equation of the saturated zone:
Base flow discharge, (Qsub) [LT-1] is calculated using the parameters m, and Te [L2T-1], catchment
mean TI, (λ) [-] and the mean storage deficit in the watershed 𝑆𝑖 [L]:𝑸𝒔𝒖𝒃 = 𝑻𝒆 𝒆𝝀𝑺𝒊 ⁄𝒎(3)Ⓒ ISERD

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c. The water balance equation of the unsaturated zone
The unsaturated zone is a temporary water storage zone that links the root zone to the saturated
zone. The mean storage deficit in the watershed at the start of the calculation (initial time step),
𝑆𝑖 is obtained from Eq. (3), assuming that the initial discharge is Q0 [LT-1].
𝑸

𝑺𝒊 = −𝒎 𝐥𝐧 𝑻 𝒆𝟎−𝝀(4)𝒆Like in Fig. 3, Si [L] expresses the storage deficit of each grid and UZi [LT-1] is the amount ofwater supplied from the unsaturated zone to saturated zone, with i being the grid number. Since,
cells with the same value of TI are considered to be hydrologically similar, computation is done foreach TI class (Fig. 2) and not for every individual grid. If Si is ≤ 0, then the TI class is considered tobe saturated, and excess water inflow from the root zone (EXi) becomes surface flow, as shown in
Fig. 3. If Si > 0, the excess water inflow is temporarily added to SUZi.
𝑺𝑼𝒁

𝑼𝒁𝒊 = 𝑺 𝒕 𝒊

(5)

𝒊 𝒅

where td [TL-1] is the delay time constant, a parameter that expresses the period of retention.
TOPMODEL requires the calibration of 5 unknown parameters, namely; exponential decay
parameter (m), mean value of downslope transmissivity when the soil is just saturated (Te), delay
time constant (td), maximum root zone storage deficit (SRmax) and initial root zone storage deficit(SRZinitial) using the Monte-Carlo method. Nush-Sutcliffe efficiency (NS) and Root Mean Square
Error (RMSE) are the evaluation functions adopted to compare agreement between observed andsimulated discharge. Having evaluated the parameters, it is then possible to simulate riverdischarge following a rainfall-runoff event.
∑𝒏 𝑬𝑽

(6)

𝐍𝐒 = 𝟏 − (∑𝒏𝟏 𝑴𝑽)
𝟏

∑𝒏 𝑬𝑽

(7)

𝐑𝐌𝐒𝐄 = √ 𝟏𝒏

Where EV is error variance ((observed value - simulated value)2), MV is mean variance((observed value – mean observed value)2) and n is number of observation days.

Fig. 5 Schematic of TOPMODEL (Source: Mukae, et al., 2017)
Data Requirement
The input data for TOPMODEL is precipitation, river discharge and meteorological data used toestimate ET0. Averaged daily data for 2015 was used. A rainfall event was defined as consecutive
days of effective rainfall, and effective rainfall as that daily rainfall ≥ 5.0 mm (Ali and Mubarak,2017).
From 2015-March-24 to 2015-December-14, 54 rainfall events were observed.
Correspondingly, the total amount of precipitation, evapotranspiration and river discharge wasⒸ ISERD

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1,646 mm, 1,149 mm and 499 mm from where it was inferred that 30% of the precipitation isdischarged to the downstream via the river.
Description of Study-defined Terminologies and Methods
Table 1 is a representation of the Sequentially Accumulated Rainfall Events (SARE) concept. All
the SARE had the same starting date but the end dates were variable.
The ‘true’ parameters were those derived from inputting all SARE in 2015 while ‘non-true’
parameters were those got by using partial SARE during model calibration. The ‘true’ parameters
were considered to be optimal for full year hydrological simulation because they were assumed torepresent an average characteristic of all observed events in 2015, which is not the case with ‘nontrue’ parameters.
The percentage error of ‘non-true’ parameters was determined by comparison with the ‘true’
parameter value – The ‘non-true’ parameters with maximum error of ± 30% were classified as
good and therefore close enough to ‘true’ value. Equation (8) shows computation of error of ‘nontrue’ parameter,.
𝒏𝒕𝒑−𝒕𝒑) × 𝟏𝟎𝟎%𝒕𝒑(8)𝑬𝒓𝒓𝒐𝒓 = (where ntp is ‘non-true’ parameter value and tp is ‘true’ parameter value.
Parameterisation was done for SARE beginning with the 1st event and sequentiallyprogressing until all 54 rainfall events in 2015 were used. In total, model calibration was done 54
times. However, it was impossible to evaluate the 1st event alone since its NS value was infinity.
Results from 1 SARE were thus omitted from further analysis.
Table 1 The SARE Concept
Rainfall event count
1
2
3
･
･
･
53
54

Sequentially Accumulated Rainfall Events (SARE)
1st event
1st event
1st event･･･
1st event
1st event

2nd event
2nd event･･･
2nd event
2nd event

3rd event･･･
3rd event
3rd event

→
→
→

･
･

･
･

･
･

53rd event
53rd event

54th event→→

Calculate unknown parameters(m , T e , t d , SRZ initial and SR max)
non-true parameter value of 1 SARE
non-true parameter value of 2 SARE
non-true parameter value of 3 SARE･･･
non-true parameter value of 53 SARE
true parameter value

Yellow indicates the partial target rainfall event(s), which is used to calculate the unknown parameters for each SARE
occurrence. Orange indicates all SARE.

RESULTS AND DISCUSSION
Parameter Descriptive Statistics
Table 2 ‘True’ and ‘non-true’ parametersm
Te (×106)td
SRZinitial
24
762
0.013
0.006
Min
18
40
0.011
0.002
Max
53
987
0.020
0.009
‘non-true’
Mean
21
587
0.017
0.006
value
s.d*
5
257
0.003
0.001
CoV**
0.25
0.44
0.16
0.24
*
Standard deviation, ** Coefficient of variance = Standard deviation / Mean‘true’ value

SRmax
0.008
0.004
0.009
0.007
0.001
0.16

NS
0.57
0.48
0.92
0.68
0.10
0.15

RMSE
0.73
0.00
0.73
0.53
0.19
0.36

Table 2 shows the descriptive statistics of the calibrated parameters. ‘Non-true’ parameter values
vary from 18 to 53, 40 to 987, 0.011 to 0.020, 0.002 to 0.009 and 0.004 to 0.009 for parameters m,
Te, td, SRZinitial and SRmax respectively. In addition, NS and RMSE varies from 0.48 to 0.92 and fromⒸ ISERD

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0.00 to 0.73 correspondingly. Based on the classification criterion of NS values by Foglia et al.
(2009), the goodness of fit varies from ‘good’ to ‘excellent’. The coefficients of variance (CoV) for‘non-true’ parameters are 0.25, 0.44, 0.16, 0.24 and 0.16 for m, Te, td, SRZinitial and SRmax in thatorder. It follows that, Te and SRmax are the most and least variable respectively. It is then clear thatthe 5 parameters are changeable depending on the number of rainfall events.

Fig. 6 Error plots of calibrated parameters
Parameter Trends
Fig. 6 is a graph of the parameter error under different numbers of SARE conditions and Fig. 5
shows the trend of evaluation functions with the number of SARE.

Fig. 7 Evaluation function under different SARE
The mean errors for SRmax, SRZinitial, m, Te and td are -8%, -10%, -13%, -23% and 37%
correspondingly. It takes 3 SARE for parameter m to stabilise within an error rage of ±30%. From
1 up to 16 SARE, Te is highly changeable, with error ranging from -95% to -54%. It requires atleast 17 SARE to stabilise parameter Te within ±30% error range. The first instance of low
observed event precipitation (9.4 mm at 10th event) seemed to cause Te value to increase sharply.
From 1 up to 18 SARE, td shows no observable trend, with error ranging from 4% to 56%.
However, from 19 to 43 SARE, parameter td stabilises within a narrow error range of 52% to 55%.
The parameter value then begins to steadily decrease at 44 SARE, eventually falling within
acceptable error range at 49 SARE. Although SRmax and SRZinitial are the least variable parameterswith respect to their means, there is no discernible trend of their behaviour with the number of
SARE. This might be because of the gross uncertainties in calibrating soil storage deficits, asⒸ ISERD

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observed by Coles et al. (1997) and Campling et al. (2002). But, different from Te, it is seen that
there is a large reduction in both SRmax (-38%) and SRZinitial (-69%) at 10 SARE.
NS and RMSE decrease and increase respectively with increasing SARE. It seems that as thenumber of SARE increases, the parameters become an average representation of many more varied
rainfall characteristics, but not the best representation for each individual rainfall event.
Parameter m is the least affected by the rainfall events inputted while parameter td is the mostaffected, requiring at least 3 and 49 SARE respectively to stabilise within ±30% error bounds.
Therefore, the minimum number of rainfall events required to calibrate TOPMODEL and to
optimise td in mid-sized equatorial catchments in Eastern Uganda are equivalent. Consequently, it
requires at least 49 rainfall events to calibrate TOPMODEL in 2015.
Summarily, it is seen that rainfall characteristics influence the parameterization of
TOPMODEL in mid-sized equatorial catchments.
CONCLUSION
A hydrological model, TOPMODEL, was applied to a different number of Successively
Accumulated Rainfall Events (SARE) to examine parameter sensitivity to rainfall characteristics. In
this study we deduce the following: (1) Dependence of calibration parameters on rainfall
characteristics was evident, with exponential decay parameter (m) being the least affected anddelay time (td) being the most affected by rainfall event characteristics; Further, (2) in mid-sized
equatorial catchments, td was the determining parameter for the minimum number of SARE needed
for calibrating TOPMODEL for yearly hydrological simulation. To confirm the observations
presented here, more yearly observed hydro-meteorological data and studies on other catchments isneeded. Furthermore, future studies should consider hydrological conditions like base flow, rainfall
intensity and effective discharge in order to better understand the effect of rainfall events.
ACKNOWLEDGEMENTS
The study was done during graduate studies at Tokyo University of Agriculture, Tokyo, Japan,
courtesy of scholarship from Japan International Cooperation Agency (JICA), Japan.
REFERENCES
Ali, M. and Mubarak, S. 2017. Effective rainfall calculation methods for field Crops: An overview, analysis
and new formulation. Asian Research Journal of Agriculture, 7 (1), 1-12.
Allen, R.G., Pereira, L.S., RAES, D. and Smith, M. 1998. FAO irrigation and drainage. Paper No. 56, Crop
Evapotranspiration (Guidelines for Computing Crop Water Requirements), Irrigation and Drainage, 300 (56),300.
Beven, K.J. and Kirkby, M.J. 1979. A physically based, variable contributing area model of basin hydrology.
Hydrological Sciences Bulletin, 24 (1), 43-69.
Campling, P., Gobin, G., Beven, K. and Feyen, J. 2002. Rainfall-runoff modelling of a humid tropicalcatchment: The TOPMODEL approach. Hydro. Processes, 16 (2), 231-53.
Coles, N.A., Sivapalan, M., Larsen, J.E., Linnet, P.E. and Fahrner, C.K. 1997. Modelling runoff generation
on small agricultural catchments: Can real world runoff responses be captured? Hydro. Processes, 11 (2),111-36.
Foglia, L., Hill, M.C., Mehl, S.W. and Burlando, P. 2009. Sensitivity analysis, calibration, and testing of a
distributed hydrological model using error-based weighting and one objective function. Water Resources
Research, 45 (6).
Gumindoga, W., Rientjes, T.H.M., Haile, A.T. and Dube, T. 2014. Predicting streamflow for land coverchanges in the upper Gilgel Abay River Basin, Ethiopia: A TOPMODEL based approach. Physics andChemistry of the Earth, 76-78, 3-15.
Japan International Corporation Agency (JICA). 2017. The project on irrigation scheme development incentral and eastern Uganda, Final Report, Volume I, Main report, Japan.
Ministry of Water and Environment (MWE). 2013. Uganda national water resources assessment. Kampala:Ⓒ ISERD

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Directorate of Water Resources Management, Uganda.
Mukae, K., Miwa, K. and Okazawa, H. 2017. Ecosystem service assesment in agricultural watershed byusing TOPMODEL. AGROFO International Journal, 2 (3), 27-36.

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Research article
erd

Effects of Earthworm Megascolicidae Population and Litter
Quantity on Soil Properties in Experimental Containers
TAKANORI KANEKO
Graduate School of Agriculture, Tokyo University of Agriculture, Japan
Email: taka1504kaneko@gmail.com

TOMONORI FUJIKAWA*
Faculty of Regional Environment Science, Tokyo University of Agriculture, Japan
Email: t3fujika@nodai.ac.jp

MACHITO MIHARA
Faculty of Regional Environment Science, Tokyo University of Agriculture, Japan
Received 28 March 2019

Accepted 20 October 2019(*Corresponding Author)

Abstract Earthworms are important soil animals and perform vital functions in the soil thatmake better conditions for ecosystem, especially agriculture. Earthworms are involved indecomposing organic matters and mineralizing nutrients, controlling populations ofpathogens, improving and maintaining soil structure and mixing organic matters in the soil.
In this study, we discussed the effects of earthworm population and litter quantity on soil
properties. Earthworm from the family of Megascolicidae was used in this study which is anative family of earthworm in Japan and accounts for more than 95% of earthworm family
there. Experimental containers were set in the laboratory where earthworm population andlitter quantity were controlled to observe its effect on soil properties. The results showed
that, there was tendency of increasing survival percentage of earthworm. The Pearson
correlation coefficient analysis showed that with increase in earthworm population and litteramount, there was increasing tendency in soil aggregates and available nitrogen content.
The results for available phosphorus content and soil microbes did not show any relation
with earthworm number and litter quantity.
Keywords earthworm, Megascolecidae, soil properties, soil aggregates, soil available
nitrogen

INTRODUCTION
Nitrogen in soil is mainly bound in organic matter (e.g. litter) and the amount of nitrogen available
for plant growth depends on complex interactions between roots, microorganisms and soil animals(Bonkowski et al., 2000). Earthworms play an important role in decomposing plant residue in the
short-term through their intensive interactions (Aira et al., 2008; Gomez-Brandon et al., 2010) withthe microbial communities. There are approximately 3000 to 4000 different species of earthworms
and are distributed according to environment conditions like temperature, soil type, water
availability in soil and organic content.
Earthworms are broadly divided into two families, Lumbricidae and Megascolicidae. Also,
they are divided into three groups according to their ecological behavior and feeds on leaf litter.
Epigiec earthworm, which lives on the surface of soil. Endogeic earthworm, which live in the soil
and feed on the soil. Lastly, anenic earthworm, which makes permanent vertical burrows on the soil.
All of them feed on leaves on the soil surface and they drag the leaves into their burrows (Bouche,1977). There are more than 100 species of earthworms found in Japan and more than 95% ofearthworms are considered to be those from Megascolecidae family. The earthworm can havenotable effects on soil structure where the density of the earthworm is high. According to Brown etal. (2001), earthworms directly affect organic matter behavior by their feeding and casting activity.
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Feeding of organic matter by Lumbricidae on organic matter increase in N, P, and K content in soil
surface and mounds of earthworm (Darwin, 1881; Salisbury, 1923; Evans, 1948). Different
earthworm ecological roles have different effects on soil aggregation and nutrient cycling. But
there are few studies on soil properties affected by earthworm population and organic matter
quantity. Also, most studies on relationship between earthworm activities and soil properties havebeen on those from Lumbricidae. The investigation of the change in the effects of Megascolicidaeby the number and soil organic matter content should be needed to estimate the earthworm
contribution on soil properties in Japan. And the size, abundance and activity of earthworm canchange in soil physical and chemical properties.
OBJECTIVE
The objectives of this study were to assess the effects of Megascolicidae population and litter
quantity on soil properties in the experimental containers.
MATERIALS AND METHODS
Sampling of Earthworms, Soil and Litter
Epigeic earthworms from Megascolicidae family (Fig. 1) were collected from depth of 5 cm soil
using hand-sorting method. Epigeic earthworms are characterized with making transient galleries
and are found till 30 cm deep in subsurface soil. The soil used in this experiment was Andosol
which are volcanic soils and covers 47% land in Japan. The soil was passed through 2 mm sieve(Fig. 2). Litter were collected from fallen leaves of oak and cereus trees (Fig. 3). The leaves were
cut up into small pieces and mixed with soil. All the samples were collected from the same field in
Kanagawa prefecture, Japan.

Fig. 1 Megascolicidae used in Fig. 2 Field where samples were Fig. 3 Litter used in this study
this study
collected(mainly oak and cereus)
Experimental Set-up
The size of experimental containers consisted of plastic box was 30 cm in length, 16 cm in breadth and5 cm in height (horizontal cross-sectional area 1/2100 a) for making similar conditions as the field (Fig.
4). The experiments were conducted for 62 days at room temperature maintained between 10 to 15 ̊C in
the laboratory (Fig. 5).

Fig. 4 Schematic diagram of experimental containersⒸ ISERD126

Fig. 5 Experimental containers
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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

The sieved soil was placed in the containers and litter and earthworms were added. Soil andlitter were mixed thoroughly. The patterns of soil organic matter content were set into three groups
of no added litter of 0% added litter, 5% added litter and 15% added litter. Each group had 5
subgroups of 0, 1, 3, 5 and 10 numbers of earthworms. For 0% added litter group, the five
microcosm treatments were named from A1 to A5. Likewise, for 5% added litter group, B1 to B5,
for 10% added litter group, C1 to C5, respectively (Table 1). Moisture content for each treatment
was tested by using gravimetric method and maintained at 50-60% with regular checking.
Table 1 Experimental treatment patterns
Litter added (%)

Number of earthworms /box
0Treatments
A1

1

A2

3

A3

5

A4

10

A5

0

B1

1

B2

3

B3

0%

5%

15%

5

B4

10

B5

0

C1

1

C2

3

C3

5

C4

10

C5

Sampling and Parameters Measured
Soil was sampled on 0, 14, 31 and 62 days from the start of the experiments. Soil was sampledfrom different points from surface of the soil. The samples were mixed thoroughly and analyzed fororganic content using ignition loss method, water stable aggregate using Yoder’s Method. And, pH
was measured using portable pH meter, total available phosphorus using Trough method, total
available nitrogen using UV absorption method and colonies of actinomycetes and fungus wereanalyzed using serial dilution and plate count method, respectively.
Statistical Analysis
Pearson coefficient correlation analysis was performed between 2 mm aggregates, total available
nitrogen, organic carbon, pH, total available phosphorus, and biological properties for results
obtained during the experiment.
RESULTS AND DISCUSSION
Survival Percentage of Earthworms
Table 2 shows the survival percentage of earthworms with different amounts of added litter. The
survival rate under the treatment with no added litter was smaller than others. Treatments where
5% of litter was used, survival rate of earthworms increased slightly compared to treatments
without any litter. Treatments with 15% of litter amount showed the highest percentage of survival
rate compared to 0% and 5% litter amount treatments. Survival rate of earthworm was in order ofⒸ ISERD

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0%> 5%> 15% to the litter amount. This result attributes to the fact that, the amount of feeding
material increasing, prolonging the survival rate of earthworms. This tendency that organic matterin the form of litter is the important factor for earthworm survival coincides with that reported in
the Brown et al., (2010) which states that earthworms directly affect matter dynamics by theirfeeding and casting activity.
Table 2 Result of survival percentage of earthworm

A2

Number of earthworms
0 day
1

Number of earthworms
62 days
1

A3

3

2

67

A4

5

4

80

A5

10

5

50

B2
B3

1
3

1
2

100
67

B4

5

4

80

B5

10

7

70

C2
C3

1
3

1
2

100
67

C4

5

4

80

C5

10

9

90

Treatments

Survival (%)
100

Relationship Between Various Parameters of Soil Properties
Significant correlations with 99% significance between 2 mm aggregates and mean weight diameter(MWD) in treatment C5 were shown from the result of Pearson correlation coefficient analysis
conducted between all the experiment parameters in 15 different treatments (Table 3). Similarcorrelation was also found in other treatments. This result is supported by the result of Kladivko et al.,(1986) which states earthworm activities increases in MWD and stability of aggregates.
No correlation was found between other parameters except for 2 mm and MWD in all treatmentsin the applied conditions. The reason for no correlations can be discussed on the behavior of anecic
earthworm, in experiment duration and scale, which might have limited the activity of earthworms. It
also coincides with results of various researches, such as Lavelle and Martin (2012) which states thatearthworm influence organic matter and nutrient during long term genesis.
Table 3 Result of Pearson correlation coefficient analysis of treatment C5
MWD

>2mm

Organic
carbonAvailable
phosphorus

pH

Available
nitrogen

Actinomycetes

MWD

1

>2mm

0.9917**

1

Organic carbon

0.76330.72161pH

0.75520.83270.43601

Available
phosphorus-0.2661-0.3864-0.0206-0.83221

Available
nitrogen0.17070.2102-0.5023

0.2745-0.2216

1

Actinomyctes-0.4791-0.52120.2012-0.54240.3600-0.9430

1

Filamentous
fungi-0.5272-0.4192-0.46960.1457-0.6662-0.0801

0.1754Note) Significant difference at **p<0.01Ⓒ ISERD

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Filamentous
fungi

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IJERD – International Journal of Environmental and Rural Development (2019) 10-2

Water Resistant Aggregate

100%

100%

90%

90%

80%

80%

Percentage of aggregates

Percentage of aggregates

Soil aggregates affects porosity, water retention ability, accumulation and decomposition oforganic matter in soil (Ketterings et al., 2002; Winsome and McColl, 1998). According to Decaens(2000), Six et al. (2002), earthworm casts are major source of soil aggregates.

70%
60%

＜0.1 mm50%0.25＞d≧0.1 mm

40%0.5＞d≧0.25 mm

30%

1＞d≧0.5 mm

20%
10%

70%

5%

50%

0.25＞d≧0.1
mm0.5＞d≧0.25mm
1＞d≧0.5mm2＞d≧1 mm30%2＞d≧1 mm

20%

≧2 mm

10%

≧2 mm
0%

15%

A1

Fig. 6 Initial conditions of aggregates at
0%, 10% and 15% litter

A2

A3

A4

A5

Fig. 7 Changes in the size of aggregate
from A1 to A5

100%

100%

90%

90%

80%

80%

70%

＜0.1 mm

60%

Percentage of aggregates

Percentage of aggregates＜0.1 mm

40%

0%
0%

60%

70%
60%

＜0.1 mm

50%

50%

0.25＞
d≧0.1 mm40%0.5＞
d≧0.25 mm

40%

30%

1＞d≧0.5
mm

30%

20%

2＞d≧1 mm20%0.25＞d≧0.1
mm0.5＞d≧0.25mm
1＞d≧0.5mm2＞d≧1 mm

10%

≧2 mm

10%

≧2 mm

0%

0%
B1

B2

B3

B4

C1

B5

Fig. 8 Changes in the size of aggregate
from B1 to B5
C1

C2

C3

C4

C2

C3

C4

C5

Fig. 9 Changes in the size of aggregate
from C1 to C5
C5

Day 0

Day 62

Fig. 10 Changes in aggregates formationin treatments from C1 to C5

Fig. 11 An aggregate formed during
the experiment (C5)Ⓒ ISERD

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It also enhances microbial activity in the soil. The changes in percentage of the aggregation by
the amount of litter shown in Fig. 6 shows the initial aggregate concentration in 0%, 5% and 15%of added litter amount. Water resistant aggregate of 2 mm increase with both the number of theearthworm population and litter amount shown in Fig. 7, Fig. 8 and Fig. 9. Treatments with highest
number of earthworm population and added litter amount had highest percentage of 2 mmaggregates. Treatment C5, with highest earthworm and added litter had 55% of aggregates formed.
From the obtained result, it can be concluded that, litter, a nutrient source for earthworms, greatly
influences the formation of water-resistant aggregates.
Available Nitrogen Concentration

A1

3.6

A2

3.4

A3
A4

3.2

A5

3.0

b**

2.8

b*
a, b
a, b

2.6
2.4

a*,**

2.2

0

4

(mg/100 g)
nitrogen （mg/100
AvaiableNitrogeng）
Available

3.8

3.8
3.6

b*

3.4

b*

3.2

a, b
a, b

3.0

B1

2.8

B2

2.6

B3
B4

2.4

a*

B5

2.2
0

8 12 16 20 24 28 32 36 40 44 48 52 56 60

4

8 12 16 20 24 28 32 36 40 44 48 52 56 60

Time（days）

Time （days）

Fig. 12 Changes in available nitrogenconcentration of A1 to A5(mg/100 g)
nitrogen（mg/100
AvaiableNitrogeng）
Available(mg/100 g)
nitrogen（mg/100
Avaiableg）
Availableitrogen

Earthworms increase nitrogen content availability for plants (Callaham and Hendrix, 1998) and theactivity of earthworms is important to plant nutrition and nitrogen cycling in the soil. The change inavailable nitrogen by earthworm activity are showed in Fig. 12, Fig. 13 and Fig. 14. The results
showed that increase in the number of earthworm population increased the available nitrogencontent. A tendency of the highest increase in available nitrogen content was seen in treatment withhighest amount of added litter quantity and earthworm population. Earthworms consume large
amounts of plant organic matter that contain considerable quantities of nitrogen, and most of thenitrogen that assimilate into their tissue is released to the soil in the form of excreta. It is concluded
that organic nitrogen changed into available nitrogen with the action of earthworms from theexperiment.

Fig. 13 Changes in available nitrogenconcentration of B1 to B5

3.8

c**

3.6

c*, **

3.4

a,b*, **
a,b*, **
a*, **

3.2
3.0

C1

2.8

C2
C3

2.6

C4

2.4

C5

2.2

0

4

8 12 16 20 24 28 32 36 40 44 48 52 56 60

Time （days）

Significant difference at **p<0.01, *p<0.05

Fig. 14 Changes in available nitrogen concentration of C1 to C5Ⓒ ISERD

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Lunt and Jacobson (1944), Graff (1971) reported that considerably increase in the amount of
nitrogen in soil surface in the field condition. Nitrogen in soil is mainly bound in the form of litterand is available to plants with complex interaction of roots, soil microbes and soil animals.
Earthworm feeds on litter and release casts which increase amount of available nitrogen. Therefore,
incorporation of litter in the soil where earthworm is present can increase casts or aggregates whichcontains nitrogen. The results also indicate that the more earthworm population and litter, the moreincrease in casts.
CONCLUSION
This study was conducted to clarify the effects of earthworm population and litter quantity on soil
properties by the action of earthworm of Megascolicidae in experimental containers. The results ofthe experiments showed that, with increase in litter amount, survival of earthworms increased.
Similarly, increasing tendency of water-resistant aggregates and available nitrogen was observed.
There was no clear relation found in available phosphorus and microbes in the given conditions. In
future, to better understand the dynamics of earthworm’s action on soil physical and chemical
properties, analysis of subsurface soil with depth due to Megascolicidae movements should be
conducted.
REFERENCES
Aira, M., Sampedro, L., Monroy, F. and Dominguez, J. 2008. Detritivorous earthworms directly modify the
structure, thus altering the functioning of a microdecomposer food web. Soil Biol. Biocbem, 53, 215-230.
Bonkowski, M., Griffiths, B. and Scrimgeour, C. 2000. Substrate heterogeneity and microfauna in soilorganic “hotspots" as determinants of nitrogen capture and growth of ryegrass. Appl. Soil Ecol, 14, 37-53.
Bouche, M.B. 1983. The establishment of earthworm communities. In Earthworm Ecology, From Darwin to
Vermiculture (Satchell, T.E. Ed.), Chapmann and Hall, 431-448.
Brown, G.G., Barois, I. and Lavelle, P. 2010. Regulation of soil organic matter dynamics and microbialactivety in the drilosphere and the role of interactions with other edaphic functional domains. Eur. J. Soil
Biol, 36, 177-198.
Callaham, M.A. and Hendrix, P.F. 1998. Impact of earthworms (Diplocardia: Megascolecidae) on cycling
and uptake of nitrogen in coastal plain forest soils from northwest Florida, USA. Appl. Soil Ecol, 9, 233239.
Darwin, C.R. 1881. The formation of vegetable mould through the action of worms. London, 326.
Evans, A.C. 1948. Studies on the relationships between earthworms and soil fertility, Ⅱ Some effects ofearthworms on soil structure. Ann. Appl. Biol., 35, 1-13.
Graff, O. 1971. Stikstoff, Phosphor und Kalium in der Regenwurmlosung auf der Wiesenversuchsflache desSollingprojektes. Ann. Zool. Ecol. Anim., Special Publ., 4, 503-512.
Gomez-Brandon, M., Lazcano, C., Lores, M. and Dominguez, J. 2010. Detritivorus earthworms modify
microbial community structure and accelerate plant residue decomposition. Appl. Soil Ecol., 44, 237-244.
Ketterings, Q.M., Blair, J.M. and Marinissen, J.C.Y. 1997. Effect of earthworms on soil aggregate stability
and carbon and nitrogen storage in a legume cover crop agroecosystem. Soil Biol., Biocbem, 29, 401-408.
Kladivko, E.J., Mackay, A.D. and Bradford, J.M. 1986. Earthworms as a factor in the reduction of soil
crusting. Soil Sci. Soc., Am. J., 50, 191-196.
Lavelle, P. and Martin, A. 1992. Small-scale and large-scale effects of endogeic earthworms on soil organic
matter dynamics in soils of the humid tropics. Soil Biol., Biochem., 24, 1491-1498.
Lunt, H.A. and Jacobson, G.M. 1994. The chemical composition of earthworm casts. Soil Sci., 58, 367.
Salisbury, E.J. 1923. The influence of earthworms on soil reaction and the stratification of undisturbed soils.
J. Linnean Soc., Botany, 46, 415-425.
Six, J., Feller, C., Denef, K., Ogle, S.M., Moraessa, J.C. and Albrecht, A. 2002. Soil organic matter, biota andaggregation in temperate and tropical soil-effects of no tillage. Agronomie, 22, 755-775.
Winsome, T. and McColl, J.G. 1998. Change in chemistry and aggregation of a California forest soil workedby the earthworm Argilopbilus papillifer Eisen (Megascolecidae). Soil Biol., Biocbem., 30, 1677-1687.

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Research article
erd

Ecotourism-related Strategies toward Increasing Tourism
Destination Competitiveness: The Case of Biliran Island
Province
VENICE B. IBAÑEZ*Visayas State University, Baybay City, Philippines
Email: venice.ibanez@vsu.edu.phReceived 25 December 2018

Accepted 20 October 2019(*Corresponding Author)

Abstract Tourism has scaled into one of the biggest and fastest economic drivers in theworld today. With the increasing number of new attractions, the imperative of assessing thecompetitiveness of tourism destinations is seen to be beneficial in improving its capability
to create competitive advantages while ensuring adherence to sustainable development
goals. Dubbed as “the best kept secret haven of Eastern Visayas”, Biliran Island Province asa tourism destination was assessed and analyzed using Porter’s Diamond Model of national
competitiveness to propose useful strategies headed towards increasing its potentials andtourism competency. A total of 33 tourism stakeholder-respondents have undergone oneon-one interview survey in the said province to describe their perspectives on theimportance and performance of various factors and conditions towards increasing its
tourism competitiveness. Importance-Performance Analysis (IPA) revealed that the tourism
competitiveness of the province is directed to its eminent natural resources, safe andsecured environment, and provisions of basic facilities. However, performance
improvement of other factors especially marketing and advertising must be addressed
promptly. Various concerns and challenges that the province facing include lack ofgovernment support in terms of product development and promotion, high taxes and cost ofother basic utilities, and environmental challenges as a result of climate change. To addressthese adversities of, ecotourism-related strategies were recommended in line with thepositioning of the province as an “Agri-Garden and Premier Ecotourism destination in
Eastern Visayas Region”. These must involve responsible marketing and advertising,human resource development and environmental-friendly infrastructures, and emphasis on
intensifying safety and disaster risk reduction and preparedness management.
Keywords ecotourism-related strategies, tourism, destination competitiveness,
Porter’s Diamond Model, Importance-Performance Analysis

INTRODUCTION
Tourism has been eyed as one of the biggest and fastest economic drivers in the world. With theincreasing number of new destinations along with the increasing investments and financing poured
to tourism worldwide, the industry transformed itself into a key driver in socio-economic progress(UNWTO, 2016). Due to its potentials for growth and contributions derived from the industry,
tourism is seen to be taking an important role in implementing strategies for local and regional
development, especially for developing countries like the Philippines.
The tourism industry portfolio of the Philippines constitutes mostly of various tourism andnative products. Among the highest ranked tourism products in the country in terms of priority arenature-based, sun and beach, and diving/marine sports tourism (DOT, 2016). This denotes that the
tourism industry in the Philippines has been greatly dependent on the natural resources for its
continued growth and existence. To ensure that these resources are responsibly used, destinations
can adopt the concept of ecotourism which offers conservation-oriented and sustainable form of
tourism.
Increasing the tourism competitiveness of a destination means enticing potential tourists andoffering and serving them with products and services better than other destinations (Mazurek,Ⓒ ISERD

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2014). In order to ensure strong and sustainable development, analysis of competitiveness should
be taken to form a sound basis for strategy formulation and policy implementation (Melisidou, etal., n.d.). Tourism competitiveness studies revolved around the identification of factors that affectthe destinations ability to attract tourists and development of possible management strategies(Crouch, 2010; Goffi, 2013; Bobircă and Cristureanu, 2006). Porter’s Diamond Model is also
widely used in studies on competitiveness (Wahogo, 2006; Bobircă and Cristureanu, 2006)
Biliran is the best kept secret haven in Eastern Visayas. With its charming community, richand wonderful coastlines and island attractions, majestic mountains, jaw-dropping waterfalls, andhigh concentration of hot springs surrounded with rich flora and fauna, the province has thepotential to become a sought-after destination for local and foreign tourists as it envisioned to
become a premier ecotourism destination.
Ironically, with all the beauty and vibrancy of the tourism endowments, for the past years,
Biliran Island Province occupied the last place in terms of its share in tourism arrival in Eastern
Visayas Region (Table 1), and 31st among the 72 provinces in the country according to the National
Competitiveness Council in 2017. Analyzing the competitiveness of the tourism sector of Biliran
Island Province is seen to be a must. This identifies the competitive strengths of the province aswell as the barriers that impede the development of the tourism sector (Navickas andMalakauskaite, 2009), more so, a fundamental concern for successful tourism management andplanning.
Table 1 Provinces in Region 8 and their major characteristics
Provinces
BiliranEastern Samar
Leyte
Northern Samar
Samar
Southern Leyte

Population inthousands (2015)
172
467
1,967
632
780
422

Land area(sq. km)536
4,660.5
6,515.1
3,692.9
6,048
1,798.6

Tourism performance*
Arrivals
Rank
31,2196
72,0605722,0101
240,9724
480,2752
391,1083

Sources of data: DOT, PSA *Based on the cumulative tourism arrivals (2011-2015)

OBJECTIVE
This research study which assessed the tourism competitiveness of Biliran Island Province used thePorter’s Diamond Model of Competitiveness that generated proposed strategies to aid in the policy
and management planning of the Provincial Tourism Office and stakeholders towards enhancing its
tourism competitiveness. Specifically, the study aimed to: (1) analyze the tourism competitivenessof Biliran Island Province using the Importance-Performance Analysis; (2) ascertain the challenges
faced by the tourism sector in the study area that impedes its competitiveness; and (3) proposed
strategies to enhance the tourism competitiveness of Biliran Island Province.
METHODOLOGY
Research approach: As a descriptive research, this assessment study employed quantitative
research approach which involved the collection of data in order to quantify them and subject the
information gathered to statistical treatment to predict, explain, and confirm knowledge claims. The
personally collected numerical data were analyzed to address the research objective(s) defined for aparticular study (Williams, 2007). Like most of the assessment studies on competitiveness done by
Wahogo, (2006), Goffi (2013), and Dwyner (2010), the survey method was used as data collection
method.
Research area: It located on the western side of the Eastern Visaya region, also Biliran is boundedby the province of Leyte on the south, Western and Northern Samar on the east, and Masbate on theⒸ ISERD

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northwest. The province is considered to be the smallest island province in the region and one of
the smallest in the entire Philippines (Fig. 1).

Fig. 1 Location map of Biliran Island Province
Retrived from en.wikipedia.org

Research respondent: A total of 33 tourism stakeholder-respondents were surveyed, of whom, 27
were owners/managers of tourism enterprises and six were staff and tourism officer of theProvincial Tourism Office of Biliran. Respondents were chosen based on their availability andconvenience.
Data collection: The two-part survey questionnaire was used in gathering the needed data toaddress the research objectives. The first part identified the profile of the respondent’s
business/company while part two determined the level of importance and performance of thevarious factors and conditions towards competitiveness that Biliran Island Province had as a tourist
destination. Micheal Porter’s Theory of Competitiveness (Porter, 1998) as illustrated by the
Diamond Model of Competitiveness is contextualized and applied to the tourism industry. The
questionnaire contained 29 items grouped in accordance to the four factors in the diamond modelfactor conditions, demand conditions, related and supporting industries, and context for firm
strategy and rivalry. The data were gathered between May to July 2018.
Data analysis: The responses of the respondents were coded using a five-point Likert scale,encoded in Microsoft Excel, and descriptive statistical analysis were sorted and summarized.

Fig. 2 The IPA grid
Adopted from Dwyner, L., 2010

Furthermore, the computed mean scores of the variables were analyzed and plotted in the
Importance-Performance Analysis (IPA) grid which aided the development of management
strategies. The median of the variables’ mean values, on the other hand, served as the central valuesof the grid, forming four quadrants. For this study, the computed central values were 4.3(importance) and 3.42 (performance). IPA combines measures of attribute importance andⒸ ISERD

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performance into a two-dimensional grid to easily interpret the data and derive practicalsuggestions (Fig. 2).
RESULTS AND DISCUSSION
Tourism Competitiveness of Biliran Island Province
Increasing the competitiveness of Biliran Island Province requires efforts to improve theperformance of various factors that have significant effect on its ability to attract and entice
tourists. Showing the result of the analysis in Table 2, the tourism competitiveness of the province
relies on its outstanding natural resources, safe and secured environment, and provision of somebasic facilities.
Table 2 Factors of competitiveness (Direct IPA)
Factors
Safety and security
Electricity
Awareness/Recognition of Hazards
Scenery
Roads
Demand by foreign customers
Landscapes and seascapes
Demand by local customers
Quality/ Skills of employees
Water system
Communication network
Legal, regulatory, and administrative
framework
Development of strategy
Marketing and advertising
Airports and seaports
Product pricing
Cost of personnel
Availability and access to locally based
suppliers
Flora and Fauna
ClimateCost of capital expansion
Joint Promotion of exhibitions, and trade
fares
Membership in organizations
Quantity of employees
Science and technology
Availability of capital
Level of rivalry

Mean Values
Importance
Performance
(y)
(x)
4.79
3.88
4.73
3.52
4.64
3.67
4.48
3.85
4.49
3.67
4.39
3.64
4.36
3.67
4.36
3.72
4.33
3.45
4.64
3.24
4.52
3.3
4.36
3.18

Quadrant
Keep up the good work
Keep up the good work
Keep up the good work
Keep up the good work
Keep up the good work
Keep up the good work
Keep up the good work
Keep up the good work
Keep up the good work
Concentrate here
Concentrate here
Concentrate here

4.3
4.3
4.3
4.24
4.24
4.18

3.42
3.09
2.76
3.48
3.42
3.33

Concentrate here
Concentrate here
Concentrate here
Concentrate here
Low priority
Low priority

4.12
4.09
4.09
4.03

3.21
3.33
3.42
2.42

Low priority
Low priority
Low priority
Low priority

4
3.88
3.82
4.15
3.78

2.67
3.24
2.18
3.55
3.52

Low priority
Low priority
Low priority
Possible overkill
Possible overkill

Source: Survey data

However, efforts should be made in order to improve the performance of the factors
positioned on the “Concentrate Here” quadrant. Marketing and advertising and product pricing are
significant factors affecting tourists’ decision-making in exploring and visiting the area (Batra,
2016). Weak tourism promotion and advertisement manifested by the absence of a website andsocial media presence, brochures and other promotional collaterals and materials impede thecompetitiveness of tourism in the province. Supporting facilities like strong and integrated
communication network, assistance for its marketing efforts, and improved transportation facilitiesⒸ ISERD

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are likewise necessary to increase the flow of tourists. Sound regulation and strategy to serve as theoverall umbrella need to be in place to ensure sustainable development of resources, and acompetitive tourism destination.
Challenges and Proposed Strategies toward Increasing Tourism Competitiveness
Table 3 shows the challenges and strategies that Biliran Island Province can adapt as it positioned
itself as an agri-garden and premiere ecotourism destination in Region VIII. A competitive ecotourism destination would require the presence of standard-compliant tourism facilities, highquality of service and skilled workers, accessible sites and destinations, distinctive souvenirs andlocal products, and a peaceful and secured environment. Moreover, the provision of infrastructure
and other support facilities towards competitiveness implies that transportation, electricity andwater are readily available for domestic and commercial consumption, and reliable internet andfunctional network coverage. As an island destination located at a hazard-prone area, theimperative of developing sustainable tourism products, coupled with disaster-prepared community
is of paramount concern in increasing the competitiveness of Biliran Island Province. On the other
hand, Biliran’s competitiveness could be enhanced with certain environmental marketing activities
and initiatives (Mihalic, 2000) which convey messages related to environmental awareness andprotection (Batra, 2006).
Table 3 Summary of Challenges and Strategies for Biliran Island Province
Challenges
High cost and inconsistent supply ofbasic facilities
Underdeveloped ports
Lack of support from thegovernment
Climate change%
response
84.84
45.45
30.30
60.60

Strategies
Developing environment-friendly
infrastructure
Establishing a Destination Management
OfficeSustainable development of natural
resources
Developing responsible marketing andadvertising program
Intensifying safety and disaster
preparedness initiatives
Enhancing human resource capacity%
response
60.60

45.45
81.81
51.51
75.75
36.36

Source: Survey data

CONCLUSION
The competitiveness of Biliran Island Province rests on the outstanding state of its natural
resources, safe and secured environment, and availability of basic utilities. Thus, in order to realize
its vision as a premier ecotourism destination in Region VIII, and at the same time, increasing its
ability to attract tourists, management strategies and policies anchored on the principles of
ecotourism should be considered and enacted.
REFERENCES
Batra, A. 2006. Tourism marketing for sustainable development. ABAC Journal, 26 (1), 59-65.
Bobircă, A. and Cristureanu, C. 2006. Competitiveness assessment and growth opportunities of the
Romanian tourism industry. Romanian Economic Journal, Year IX, 21.
Crouch, G. 2010. Tourism, competitiveness, and societal prosperity. Journal of Business Research, 44 (3),137-152.
Department of Tourism. 2016. National tourism development plan 2016-2022.
Dwyner, L. 2010. Destination competitiveness: An overview of some issues.
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Goffi, G. 2013. Determinants of tourism destination competitiveness: A theoretical model and empiricalevidence.
Mazurek, M. 2014. Competitiveness in tourism - models of tourism competitiveness and their applicability:
Case study Austria and Switzerland. European Journal of Tourism, Hospitality and Recreation Special
Issue, 73-94.
Melisiduo, G., Papageorgion, A., Papayiannis, D. and Varvaressos, S. n.d. Tourism cluster as a potentiallyeffective tool for local development and sustainability. Journal of Touris Research, IX.
Mihalic, T. 2000. Environmental management of a tourist destination a factor of tourism competitiveness.
Tourism Management, 21, 65-78.
National Economic Development Authority. 2011. Eastern Visayas regional development plan, 2011-2016.
Navickas, V. and Malakanskaite, A. 2009. The possibilities for the identification and evaluation of tourism
sector competitiveness factors. Engineering Economics, 1, 61.
Porter, M. 1998. Clusters and the new economics of competition. Harvard Business Review, NovemberDecember 1998, 77-90.
Stange, J. and Brown, D. 2018. Tourism destination management: Achieving sustainable and competitive
results. Online Tool Kit and Resource Series.
United Nations Environment Programme. 2008. Disaster risk management for coastal tourism destinations
responding to climate change: A practical guide for decision makers. UNEP, ISBN: 978 92 907 2922 2
United Nations World Tourism Organization. 2016. Tourism highlights. 2016 Edition.
Wahogo, J. 2006. An application of porter`s diamond model to analyze competitiveness of Kenya`s tourism
industry. Masteral Thesis.
Williams, C. 2007. Research methods. Journal of Business and Economics Research, 5, 3.

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Research article
erd

GIS-based Analysis for the Energy Potential and Social
Feasibility of Small-Scale Run-Off-River Hydropower inYahagi River, JapanYURI YAMAZAKI*
Faculty of Regional Environment Science, Tokyo University of Agriculture, Tokyo, Japan
Email: yy206792@nodai.ac.jp

KIICHIRO HAYASHI
Institute of Materials and Systems for Sustainability, Nagoya University, Nagoya, JapanNOBUKO KAWAGUCHI
Institute of Materials and Systems for Sustainability, Nagoya University, Nagoya, Japan

HIROMU OKAZAWA
Faculty of Regional Environment Science, Tokyo University of Agriculture, Tokyo, Japan

FERDINANDO VILLA
Basque Centre for Climate Change, Leioa, Spain
Received 15 January 2019

Accepted 20 October 2019(*Corresponding Author)

Abstract Due to the increase in international energy demand and the focus on therealization of a decarbonized society, small-scale hydropower plant is attracting attention in
Japan as an important supply of renewable energy. While Japan has a significant amount ofprecipitation and mountains, it is suitable to establish hydropower plants; however,hydropower energy currently represents only about 10% of the total energy mix. Generally,a small-scale hydropower facility has relatively little impact on the environment and is
expected to play a role as a distributed power source. However, it has not been included in
the survey of hydropower potential, and a study on its viability and the development ofpotential sites is limited. Here, we created an electricity generating capacity map for smallscale run-off-river hydropower plant of the Yahagi River system in Aichi, Japan. We
calculated the river flow rate and potential electricity generating capacity at every 10 m on
the river line of the Yahagi River system using the digital elevation model, published by the
Geospatial Information Authority of Japan. We overlapped various kinds of social
conditions and risks on the map of electricity generating capacity and proposed a suitablesite where the development of potential small-scale run-off-river hydropower plant is high.
Keywords small-scale run-off-river hydropower plant, renewable energy, GIS,
Yahagi River

INTRODUCTION
Due to rapid increase in the number and degree of natural disasters in Japan, the dissemination andpromotion of renewable energy and distributed power sources have become a more critical policy
issue (Agency for Natural Resources and Energy, 2018). In recent years, the following three
conditions have been identified for energy supply: (1) securing small-scale and distributed
generation functions to mitigate the risk of a sudden drop in power supply in the event of a disaster,(2) enhance base-power supply capacity to respond to peak demand in summer and winter, and (3)a generator that is self-sufficient and does not emit greenhouse gases (Ueda et al., 2012). Smallscale hydropower is generally considered to create a low environmental load and a high degree ofaffinity for distributed power supply.
However, there are few noticeable cases of mini and micro hydropower projects that target theⒸ ISERD

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power generation output of around 100 kW. Hydropower plants are mainly of two types of namely,
reservoir and run-off-river hydropower plants. While reservoir-types such as dams can generate
medium to large-scale hydropower, the places where power plants can be installed are limited, andthe installation costs are relatively high. Conversely, a run-off-river type can generate small-scalehydropower and the installation of plants is relatively easy. Also, power generation is possible evenin complex terrain conditions such as mountainous areas. Recently, European attractive policies arefavoring the construction of new small-scale hydropower plants, i.e., in most cases, correspond to
run-of-river hydropower plants (Garegnani et al., 2018).
While estimating the feasibility of renewable energy development projects, a fundamental
challenge is to determine the availability of the natural resources. In the planning process, further
restrictions in the exploitation of natural resource (e.g., technical, environmental, legal, and social)should be considered (Moriarty et al., 2012; Resch et al., 2008). For example, in Japan, theMinistry of the Environment Government of Japan estimates the medium to small-scalehydropower energy potential values in rivers and agricultural water by prefecture (the Ministry of
the Environmental Government of Japan, 2011). Also, the potential of small hydropower isestimated around the world (Cuya et al., 2013; Kusre et al., 2010; Yah et al., 2017).
In this study, the development of a potential estimation method for small-scale hydropower,
which can be applied more simply and on a global scale in the future, is considered by assuming a
run-of-river type and low-drop type power plants. Also, the electricity generating capacity of smallscale hydropower and the amount of power required were compared.
METHODOLOGY
Study Sites
In this case, the Yahagi River system was targeted for the case study (Fig. 1). The Yahagi Riversystem flows down to Nagano Prefecture, Gifu Prefecture, and Aichi Prefecture, which has a total
stream length of 117 km and a catchment area of 1,830 km2.
Creation of Potential Estimation Point for Small-scale Hydropower
The ArcGIS (Ver.10.4 and Ver.10.6) calculated the stream length and the catchment area, and theDigital Map 10 m Grid (Elevation) published by the Geospatial Information Authority of Japan(GIS) and the Hydrology analysis tools of Spatial Analyst (ArcGIS) were used. The streamline wasselected using the Digital Map, and the point data were created on the streamline at 10-meterintervals as a potential estimation point of hydropower (Fig. 2). We calculated the watershed area
at each point.
Estimation of the River Discharge
The river discharge at each potential estimation point was estimated. A specific discharge rate wasused to calculate the river discharge. The actual river discharge values obtained from six
observation sites of Water Information System (MILT of Japan, 2018), i.e., Sumigase, Kugyudaira,Yonedu, Kido, Takahashi, and Iwadu, were then corrected. At these sites, normal flow rates were
calculated using the river discharges per day from January 1st, 2016 to December 31, 2016. A
normal flow rate represents river discharges that do not fall below this value for 185 days
throughout one year. There was a significant correlation between the watershed area and a normal
flow rate at these six observation sites (correlation coefficient (r) = 0.93, p values of significancetest (p) < 0.01). In addition, the potential estimation points correspond to the six observation sitesof Water Information System. There was a significantly strong correlation of watershed areas
between of the potential estimation points and of the six observation sites (r = 0.99, p < 0.01).
From these results, the specific discharge rate of the Yahagi River system (0.0254) was calculated,Ⓒ ISERD

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and the river discharges at each potential estimation point was calculated by multiplying awatershed area by the specific discharge rate.
Calculation of Electricity Generating Capacity
The electricity generating capacity of a small-scale hydropower is expressed by the formula (1).
𝑃𝑒 = 9.8 × 𝑄 × 𝐻𝑒 × 𝜂(1)3

where Pe is the amount of power generated (kW), Q is the river discharge (m /s), He is the height
difference between inlet and outlet of stream (m), and 𝜂 is a dimensionless efficiency of theturbine.
Out of these, the height difference can be adjusted according to the local topography or theamount of electricity. In this study, since the target is the small-scale and low-drop hydropower
plants, the He is uniformly set to 5 m at each point. Furthermore, in this study, we targeted on the
power generation amount ranged from 30 to 500 kW, and values less than 30 kW and greater than
500 kW were excluded from the potential estimation analysis.
Extraction of a Social Condition(1) Spatial duplication in a nature reserve area:
Since the artificial development practices are regulated in the area designated as the nature reserve
are, the points located in the nature reserve area among the potential estimation points were
excluded. The potential estimation points were excluded in the Natural park areas (MILT of Japan,
2015a), Nature conservation areas (MILT of Japan, 2015b) and Wildlife management areas (MILT
of Japan, 2015c) and within their 100 m buffer areas.

Fig. 1 Location of the Yahagi River

Fig. 2 The potential estimation points ofsmall-scale hydropower(2) Spatial duplication in disaster risk areas:
Since the establishment of small-scale hydropower facilities in areas designated as disaster risk
areas are not realistic, the points located in the disaster risk area of the potential estimation points
were excluded. Sediment disaster hazard areas (MILT of Japan, 2010) and landslide special
warning areas (MILT of Japan, 2017) are targeted in a 50 m buffer area, and the flood eliminate
area (MILT of Japan, 2012) excluded points that were included within a 100 m buffer area.
(3) Distance from the existing road:
When constructing a small-scale hydropower facility, its distance from the existing road influences
the installation cost. Therefore, the linear distance from the newly-installed power generation
facility to the existing road was calculated using the Road Edge data published by Geospatial
Information Authority (GSI, 2017), assuming the necessity of laying the power distribution for theⒸ ISERD

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construction and management of roads. Out of the estimated linear distances, the potential value
was calculated as the maximum value of 1.0 in the case of 100 m or less, and the potential value
using formula (2) when it was larger than 100 m.
100

𝑃𝑛 = 𝐷(2)𝑛where Pn is a potential value of the potential estimation point’s number n, and Dn (m) is the nearest
distance from the potential estimation point. The potential value decreased as the distance from thepotential estimation point to the existing road increased.
Estimation of the Required PowerThe amount of power required per year was calculated by multiplying the number of houses,
included in the concentric circle at center of the potential estimation point, by the power usage perhousehold at each potential estimation point. With respect to the number of houses, assuming one
urban area cell (10 m) as one household from the JAXA (2016) High Resolution Land-Use andLand-Cover Map (Ver. 16.09; 10 m × 10 m spatial resolution), the total number of urban area cells
included in the 1.0 km circles are used to obtain the potential estimation point. An average value((kWh / h / household) of electricity consumption in the five years from 2005 to 2010 is calculated
from the "Trend of power consumption per household" provided by The Federation of ElectricPower Companies of Japan (2017), which is multiplied by the number of households to calculate
the power requirement.
Reclassifying of the Potential Estimation Points into Sections
The consecutive points, excluding spatial duplication points in the nature reserve and disaster risk
areas, were grouped as one section. Using neighbor analysis of ArcGIS, the points adjacent in eight
directions from the potential estimation point were reclassified as a single section.
Site reconnaissance:
We investigated the local conditions of the potential estimation points created and excluded by GIS.
On December 21, 2018, seven locations in Ena City and Toyota City were surveyed. Survey items
included river width, seawall structure of riverbed, right bank and left bank, and the presence oftransmission line.
RESULTS AND DISCUSSION
In the Yahagi River system, the potential estimation points were created at 10 m intervals. Then we
excluded the potential estimation points by the spatial duplicated area of the nature reserve and thedisaster risk areas. Moreover, where the amount of power generation is less than 30 kW and greaterthan 500 kW were also excluded. The potential estimation points were narrowed down to 4,038
points from 106,494 points (Fig. 3).
The minimum value of power generation at 4,038 points was 30.1 kW, the maximum value
was 397 kW, and the average value was 113 kW. Besides, 57% of the 4,038 points had a microscale power generation of 50 kW or less (Fig. 4). When classifying the points as connected in eight
directions out of a potential estimated number of points, 4,038 points were sorted into 125 sections.
Moreover, 125 sections were located in five areas of the Yahagi River system.
Based on the distance of the existing road from the small-scale hydropower facility, we
determined the cost of installation of this facility. The distance to the existing road at 4,001 points
out of 4,038 points was 100 m or less. Hence, it is possible to install and manage the facilities using
existing roads at most potential estimation points.
The amounts of required power generation within 1 km from the potential estimation point
were compared. In this instance, the power generation amount and the required power amount wereconverted into annual values. The annual power generation amount at 4,038 points ranged fromⒸ ISERD141

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264 to 3,480 MW/y, and the average value was 996 MW/y (Fig. 5). The number of points where
the ratio of the power generation amount to the required amount was less than 100% (except 0%)
was 1,186 points, i.e., 51 sections. Among these points, the points below 10% of the ratio of thepower generation amount to the required amount were 402 points, i.e., 24 sections, and these
sections were located in the population concentrated areas within Toyota City (Fig. 6). The
population within 1 km from these potential estimation points is relatively large; the required
amount is also large compared to the amount of power generation. For this reason, the installationof small-scale hydropower facilities in this section can be considered unsuitable.

Fig. 3 Potential estimation points(red colored points)

Fig. 4 Histogram of power generation

Fig. 5 Power generation of 4,038 ofpotential estimation points

Fig. 6 Ratio of the demand to
the power generation

Conversely, at 784 points, where the ratio of the power generation amount to the required
amount is higher than 10% and less than 100%, small-scale hydropower facility is useful for local
production and consumption.
At around 100% (2,443 points), where the population concentration is low, and the amount of
power generated exceeds the requirement, small-scale hydropower facility can be used for powerselling.
Based on these results, to evaluate the validity of the potential estimation points of small-scalehydropower facility published by GIS, a site reconnaissance was conducted in three areas, as
shown in Fig. 7. These three areas have relatively lower population concentration and are located in
the mountainous regions of Japan.
In the section where the village is near the river, it is generally accepted that the small-scalehydropower facility for the local production and consumption type is sufficient. By site
reconnaissance, roads and power transmission lines are being maintained, the river is also managed,Ⓒ ISERD

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and the flow conditions are stable. From this, it was inferred that even in the mountainous areas, it
is possible to install a power generation facility at a relatively low cost near the settlement, and asmall-scale power generation facility according to the size of the village is suitable.
Conversely, since most of the target sections have few settlements, it is considered that the use
as a power-selling type is suitable.
In these sections, it was confirmed that there is an existing road near the river, but there is no
power transmission line. In addition, there are many natural rivers, including sprawl points, where
flow paths are complicated with big rocks of river beds. At such points, there is a concern that highcosts will be incurred for the installation of power generation plants. In the case of valley terrain,
the distance from the existing road to the river is long, and there is a concern that the installationand management of the power plant are complicated.

Fig. 7 Location of site reconnaissance
However, even if there are no settlements near the points, small-scale hydropower plant withexisting irrigation facilities such as weirs is considered to be effective. In the vicinity of irrigation
facilities, since the river flow is stable, low cost and stable power generation are expected. By
combining existing irrigation facilities with small-scale hydropower facilities, it is possible toallocate administrative expenses for irrigation facilities.
Several tasks remain to apply the potential estimation method of this study in other regions
and on a global scale. In this study, we set the buffer to 100 m in the extraction of social conditions;
it is necessary to verify the proper distance. In the calculation of the distance to existing roads, 100m buffer from the center point of the river was used as the standard. However, it is expected thatthe river width dramatically varies depending on the size of the river. For example, the river width
in the upstream river is small in general, and even if the distance from the center of the river iswithin 100 m, the distance could be far away from the estimation point.
Conversely, when large rivers are included, the river width may be 100 m or more, and it may
be impossible to calculate the distance to existing roads. It is necessary to change the distance tothe existing road for each point considering the width of the river, the topography, and the flow
rate. Based on the results of the site reconnaissance, it showed that the utilization of existing
irrigation facilities is useful. However, position information on small facilities such as weirs isoften not released as GIS data, and it is difficult to estimate the potential considering existing
facilities. Likewise, we have not considered the positional relationship with existing power
generation facilities. However, considering the balance with the demand amount, it will benecessary to consider the necessity of the power generation facilities to be nearby.
CONCLUSION
In this paper, we suggest a potential estimation method for a small-scale hydropower plant. The
results showed a suitable point for small-scale hydropower generation facilities in more detail byⒸ ISERD

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public information. It is necessary to confirm the environmental conditions around the river andnear the field by the site reconnaissance in the mountainous areas where the population is low.
Also, in order to evaluate the more realistic energy potential, it is necessary to identify the locationof existing irrigation facilities and power generation facilities and to examine the relevance ofsmall-scale hydropower generation.
ACKNOWLEDGEMENTS
This research was supported by the joint usage / research program of the Institute of Materials andSystems for Sustainability (IMaSS), Nagoya University.
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National Land Information Division, National Spatial Planning and Regional Policy Bureau. 2010. Sedimentdisaster hazard area data. Ministry of Land, Infrastructure, Transport and Tourism, Government of Japan,
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National Land Information Division, National Spatial Planning and Regional Policy Bureau. 2012. Flooddisaster prone area. Ministry of Land, Infrastructure, Transport and Tourism, Government of Japan,
Retrived from http://nlftp.mlit.go.jp/ksj/gml/datalist/KsjTmplt-A31.html (in Japanese).
National Land Information Division, National Spatial Planning and Regional Policy Bureau. 2015a. Naturalpark region data. Ministry of Land, Infrastructure, Transport and Tourism, Government of Japan,
Retrived from http://nlftp.mlit.go.jp/ksj/gml/datalist/KsjTmplt-A10-v3_1.html (in Japanese).
National Land Information Division, National Spatial Planning and Regional Policy Bureau. 2015b. Nature
conservation areas data. Ministry of Land, Infrastructure, Transport and Tourism, Government of Japan,
Retrived from http://nlftp.mlit.go.jp/ksj/gml/datalist/KsjTmplt-A10-v3_1.html (in Japanese).
National Land Information Division, National Spatial Planning and Regional Policy Bureau. 2015c. Wildlife
management area data. Ministry of Land, Infrastructure, Transport and Tourism, Government of Japan,
Retrived from http://nlftp.mlit.go.jp/ksj/gml/datalist/KsjTmplt-A15.html (in Japanese).
National Land Information Division, National Spatial Planning and Regional Policy Bureau. 2017. Landslide
special warning area data. Ministry of Land, Infrastructure, Transport and Tourism, Government of Japan,
Retrived from http://nlftp.mlit.go.jp/ksj/gml/datalist/KsjTmplt-A33-v1_3.html (in Japanese).
Resch, G., Held, A., Faber, T., Panzer, C., Toro, F. and Haas, R. 2008. Potentials and prospects for renewableenergies at a global scale. Energy Policy, 36 (11), 4048-4056.
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agricultural dams in Tohoku region. Tech. Rep. Natl. Inst. Rural Eng. Japan, 212, 137-156. (in Japanesewith English abstract).
Yah, N.F., Oumer, A.N. and Idris, M.S. 2017. Small scale hydropower as a source of renewable energy in
Malaysia: A review. Renewable Sustainable Energy Review, 72, 228-239.

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Research article
erd

Farming Practices Assessment and Economic Analysis of
Organic Rice Farming in Cambodia:
Case Study of a Commune in Preah Vihear Province
CHANMONY SOK*
Graduate School of Agriculture, Tokyo University of Agriculture, Japan
Email: Chanmony0223@gmail.com

TOMOHIRO UCHIYAMA
Faculty of International Agriculture and Food Studies, Tokyo University of Agriculture, Japan

NINA N. SHIMOGUCHI
Faculty of International Agriculture and Food Studies, Tokyo University of Agriculture, Japan
Received 15 December 2018

Accepted 31 October 2019(*Corresponding Author)

Abstract Through the Cambodian government program, adoption of organic rice farming
started in 2003. Although some farmers re-converted back to conventional rice farming,
there are still some farmers who have continued producing organic rice under contract
farming and non contract farming. This study aims to (1) clarify the cultural practices oforganic rice farming; (2) compare the productivity and profitability of organic rice undercontract farming and non-contract farming, and (3) identify the perception of farmers
towards organic rice farming and reasons why they have continued. This study interviewed
85 randomly selected farmers in a commune of Preah Vihear province and further divided
them into three types: 32 contract farmers, 32 non-contract farmers, and 21 organic ricecontract farmers who partly sold produce outside the contract. Results showed that althoughtransplanting and direct-seeding were prevalent, direct-seeding was the most common
practice due to limited labor and rice field location. With regards to productivity andprofitability, organic rice contract farmers had more yield and earned more profit than noncontract farmers. Moreover, farmers practicing transplanting had higher yield than those of
direct-seeding. However, availability of exchange labor seemed to be a critical factor for
farmers to gain profit. The reasons for farmers to continue doing organic rice farming werehigher income, better health and contribution to conserve the environment. The reasons forengaging in contract farming were receiving stable and high price and gaining new
knowledge. This study hopes to initially contribute to the further development of organic
rice farming in Preah Vihear province.
Keywords contract farming, cost and return analysis, cultural practices, organic rice,
perception

INTRODUCTION
In Cambodia, agriculture contributed to 28.6% of GDP (2015), while contribution of rice alone
accounted for 10%. Recently, the demand for organic products (e.g. organic rice) is significantly
increasing due to the increasing number of local people who prefer to consume safe food and live ahealthy lifestyle. Moreover, organic rice production for export to European countries is increasing
year by year. However, the adoption of organic rice practice only started in 2003. Thus, it isundoubtedly a latecomer on the international organic agriculture scene (COrAA, 2011).
Taing (2008) mentioned that social and economic benefits of organic rice farming are not yet
sufficiently clarified. During the first few years, Cambodian rice farmers produced organic ricewith surprising success, and many organic rice cooperatives were established throughout the main
rice production areas in Cambodia. However, many organic rice farmers diminished in scale, andⒸ ISERD

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many organic rice farmers re-converted to conventional farming even though Taing (2008) and Sa(2011) reported that organic farming could increase farmers’ rice yield and profit.
According to Preah Vihear Provincial Department of Agriculture (2017), there are agricultural
cooperatives that still produce organic rice in a natural way without external inputs such fertilizers
and pesticides in Preah Vihear province. In 2017, this province produced almost 30,000 tons oforganic rice from 5,162 smallholder farmers who engaged in contracts with three different privatecompanies (contractors).
OBJECTIVE
This study aims to (1) clarify the cultural practices of organic rice farming; (2) compare theproductivity and profitability of organic rice under contract farming and non-contract farming, and(3) identify the perception of farmers towards organic rice farming and reasons why they havecontinued.
MATERIALS AND METHODSThis study was conducted in a commune of Preah Vihear Province, which is the second largest
agricultural area in Cambodia. The main commodities are rice, rubber, and cashew nuts. It is
located in the Northern area of the country and shares international border with Thailand and Laos.
This province is also considered as the “Kingdom of Organic Rice.” Most people are farmers whogrow rice during wet season only because of no irrigation or canals. On another hand, the selected
commune had a population of 8,296 person (2016) and covered a total area of 36,535 ha of mostly
hilly forest, located 396 km. from Phnom Penh City. This commune was selected because many
farmers are cultivating organic rice (Provincial Department of Agriculture, 2017).
Primary data were collected through questionnaire survey of randomly selected organic rice
farmers and key-informant interviews (e.g. agriculture officers and other stakeholders) in Marchand August 2017. A total of 85 organic rice farmers were interviewed and further divided them into
three types: 32 contract farmers, 32 non-contract farmers, and 21 organic rice contract farmers who
partly sold their produce outside the contract (hereafter, mixed farmers).
Descriptive analysis and cost and return analysis were utilized in this study.
RESULTS AND DISCUSSION
Socio-Economic Characteristics of Selected Organic Farmers
New farmers who engage in contract farming are usually required to pay 50% of certification fee,
while the other 50% is paid by the private company (contractor). However, during the introductionof contract farming in 2017, an NGO extended support to all contract farmers through payment of
the farmer’s share to the certification fee. Moreover, contract farmers were provided organic riceseeds and training sessions on organic rice standards, certification application process, organic
cultivation, and internal control system.
Table 1 Socio-economic characteristics of selected organic farmers (n=85)
Items

Contract farmer

Non-contract farmer

Mixedfarmer1
21.0
34.8
5.5
4.4
18.7

Number of household (HH)
32.0
32.0
Average age (years old)
37.8
39.9
Average family size (person)
5.3
5.7
Average education (years)
4.9
4.7
Average farming experiences (years)
19.8
22.6
Source: Field survey, 2017
Note: Mixed farmers refer to those farmers who engaged in contract farming but sold part of their organic rice produce
outside the contract.
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Table 1 shows the general profile of the three groups of farmers. The average household wasabout five members in each group. Non-contract farmers were the oldest and had the longest
farming experience among the groups. On another hand, contract farmers had the highest
educational attainment.
Cultural Practices
The field survey revealed that selected farmers commonly cultivated white rice variety (known as
Neang Om and Neang Ouk in Khmer language). This variety has long maturity (specifically, 8months) and is suitable for wet season and land condition in the study area. Farmers commonly
start land preparation from May and do harvesting between late-November and early December.

Fig. 1 Total land size by farmer type and crop establishment
Source: Field survey, 2017

As shown in Fig. 1, all groups practiced both types of crop establishment (e.g. direct-seeding
and transplanting). Particularly, all farmer respondents preferred direct-seeding due to shortage oflabor and the long distance of rice paddy field from home.
Table 2 Cultivation practices by farmer group and crop establishment

Pre-cultivation

Cultivation

Pre-cultivation

Cultivation
stage
Farm location
Seed (kg/ha)
Land preparation
Seedling age
Space between line and row
Transplant (seedling per hill)
Seedling depth into soil
Weed control
Pest control
Irrigation

Farm location
Seed (kg/ha)
Land preparation
Weed control
Cultivation
Pest control
Irrigation
Source: Field survey, 2017

Transplanting
Contract
farmerNear home
73.95
3 times18- 21 days
20-25 cm
1 seedling
2-3 cm deep
Hoes and hand
Spiders and frogs
RainfedDirect-seeding
Far from home148.28
3 times
Hoes and hand
Spiders and frogs
RainfedⒸ ISERD

148

Non-contract
farmerNear home
78.62
2 timesMore than 20 days
<20cm
2 or 3 seedlings>3cm
Hoes and hand
Spiders and frogs
RainfedMixed
farmerNear home
81.37
Less than 3 times
3 weeks
25-30cm
1 seedling
2-3cm
Hoes and hand
Spiders and frogs
RainfedFar from home
150.03
2 times
Hoes and hand
Spiders and frogs
RainfedFar from home
125.21Less than 3 times
Hoes and hand
Spiders and frogs
RainfedIJERD – International Journal of Environmental and Rural Development (2019) 10-2

It should be noted that non-contract farmers had limited or no special trainings, thus most ofthem followed their own cultivation practice. On the other hand, contract farmers and mixed
farmers attended some short trainings organized by the NGO, agricultural cooperative union and/or
contract companies on organic rice cultivation in order to get international organic certification.
Table 2 shows the differences in cultivation practices by farmer group and crop establishment. The
main differences found were seed input and land preparation. First, non-contract farmers selected
seeds for next production by themselves, so seeds were not genetically selected. The selection was
based on the physical aspect of the rice plant and seed (e.g. thickness and weight). Before sowing,
the unhealthy grains are taken out. However, although contract farmers were initially provided withorganic rice seeds for free by the contractor in 2017, they had the option to buy or keep seeds forthe next cropping. Second, with regards to land preparation, contract farmers did three times, while
non-contract farmers did two times.
During harvesting, all the farmers harvested by hand and sun-dried rice grain on the field. This
practice significantly affected grain quality. All farmers utilized threshing machine.
Production Cost of Organic Rice Farming
The analysis was done separately in three groups namely contract farmer, non-contract farmer, andmixed farmer. Each group was divided into two different kinds of cultivation practices such as
direct-seeding and transplanting. It should be noted that all the cash cost and non-cash cost such as
family labors cost, exchange labors cost, and depreciation cost on farm assets were included in thecalculation. Family labor cost, exchange labor cost, and seeds cost were considered as non-cash
costs. Family or exchange labor cost was estimated as 2.5 USD per person (about half day or 4hours).
Table 3 Total labor cost of organic rice production
Contract farmer
Non-contract farmer
Mixed farmer
Direct-seeding
Transplanting
Direct-seeding
Transplanting
Direct-seeding
Transplanting
Items
Family Exchange Family Exchange Family Exchange Family Exchange Family Exchange Family Exchange
labor
labor
labor
labor
labor
labor
labor
labor
labor
labor
labor
labor
1st plowing
5.75
6.37
5.60
5.98
5.38
5.70
2nd plowing
5.44
5.29
4.98
5.55
Harrowing
2.49
2.53
2.52
2.44
2.36
3.20
Direct-seeding
9.95
9.79
9.73
Transplanting
11.82
108.36
11.66
109.3012.75
105.63
Weeding
34.05
31.79
21.79
29.85
29.21
30.87
Harvesting
13.84
111.16 14.46
110.23 13.22
111.94 12.90
107.28 12.51
106.90 15.03
108.74
Threshing
17.41
5.91 17.10
5.13 15.55
4.35 15.86
4.04 11.64
7.52 10.02
5.59
Transportation
5.21
4.90
5.21
4.98
4.43
3.93
94.14
117.07
94.26
223.7373.67
116.2983.66
220.6280.24
114.41
87.03
219.97
Total
211.21
317.99189.97304.28194.65307.00Source: Field survey, 2017
Unit: USD/ha

Table 3 shows that farmers did not have enough capability to hire and pay many laborers to dotransplanting and harvesting, so farmers commonly used exchange labor. The result of the study
revealed that the total labor cost of contract farming was about 211.21 USD/ha and 317.99 USD/haof direct-seeding and transplanting, respectively. The total labor cost of direct-seeding andtransplanting of contract farming were higher than the other two groups. Harvesting time had thehighest share of labor inputs because it was done by hand.
Table 4 shows that contract farmers and mixed farmers spent higher fuel consumption during
land preparation than non-contract farmers because non-contract farmers did only two times in land
preparation while other groups three times in land preparation. Hand tractor was the highest fixed
cost for all groups. The total fixed cost is equivalent to deprecation cost, which calculated using thestraight-line method of depreciation (Rahman et al., 2013).

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Table 4 Total variable cost, fixed cost, and production of organic rice production
Contract farmer
DirectTransplanting
seeding
32
18

Items

NHH
Variable cost
Fuel consumption of 1
1st plowing
5.27
5.38
2nd plowing
4.57
4.47
Harrowing
3.01
2.98
Transportation
9.23
7.20
Seed 2
44.26
22.07
Threshing 3
18.15
19.09
Fixed Cost
Hand-tractor
57.12
54.58
Sickle
0.32
0.27
Hoe
0.58
0.47
Blue sheet
5.53
5.07
Sack
5.03
5.29
Total Labor cost
211.21
317.99Total production cost
364.28444.87
Source: Field survey, 2017
Note:1. Diesel cost was 0.7 USD per 1L.
2. Seed cost was 0.3USD per kg.
3. Threshing cost 1/30 of total production paddy rice.

Non-contract farmer
DirectTransplanting
seeding31
22

Mixed farmer
DirectTransplanting
seeding
21
13

5.45
2.99
9.53
44.79
16.94

5.38
2.98
7.83
23.47
17.36

5.31
4.60
3.05
9.10
37.38
17.19

5.45
4.53
3.02
7.83
24.29
17.56

66.57
0.34
0.55
5.61
4.69
194.79352.24

53.81
0.33
0.56
4.36
4.81
309.26430.14

62.32
0.31
0.51
5.56
4.76
194.65344.74

54.80
0.33
0.56
4.36
4.86
307.00434.60
Unit: USD/ha

Productivity and Profitability of Organic Rice Production
Regarding profitability, this study examined several indicators such as gross revenue, total cash
income, and net profit of organic rice production in each group. Gross revenue was calculated byyield (tons/ha) multiplied with the price (USD/ton). There are two different ways to examine
profitability such as net profit which was calculated by gross revenue minus total production cost,
and total cash income which was calculated by gross revenue minus total production cost andminus non-cash cost. The cost of certification was not included in the calculation because no
farmer paid since it was subsidized by the contractor and NGO.
Table 5 Net profit of organic rice farming production
Contract farmer
Items

Directseeding

Transplanting

Yield (tons/ha)

2.19
243.47533.0584.50
68.58
211.21
255.47364.28424.24168.772.30
242.38557.9061.20
65.68
317.99340.06444.87453.09113.04

Paddy price (USD/ton)

Gross revenue
Total variable cost
Total fixed cost
Total labor cost
Total noncash cost 1
Total production cost
Total cash income2
Net profit 3

Non-contract farmer
Directseeding

2.04
185.52379.1379.69
77.76
194.79234.75352.24261.6426.89

Transplanting

2.09
184.94387.2657.02
63.86
309.26327.75430.14284.87(42.87)

Source: Field survey, 2017
Note: 1. Total noncash cost = Seed cost+ Labor cost
2.Total cash income = Gross revenue - (Total production cost -Total noncash cost)
3.Net profit = Gross revenue - Total production cost

Mixed farmer
Directseeding

2.07
208.78432.74
76.62
73.46
194.65232.03344.74320.0388.00

Transplanting

2.12
203.32430.6662.69
64.91
307.00331.29434.60327.35(3.94)
Unit: USD/ha

Table 5 shows that contract farmers received the highest price and yield among the groups on
both cultivations. These are the reasons why contract farmers could generate gross revenue morethan other farmer groups. Even contract farmers had higher production cost than others, contract
farmers still earned higher net profit and cash income. Ingeneral, farmers earned higher total nonⒸ ISERD150

IJERD – International Journal of Environmental and Rural Development (2019) 10-2

cash income in transplanting than direct-seeding. On the other hand, farmers could earn more net
profit in direct-seeding rather than transplanting because transplanting need much more labor
requirement. Moreover, non-contract farmers and mixed farmers were not able generate net profit
in transplanting.
Farmer Perception
In general, the main reasons for farmers to engage in organic rice were no fertilizer expense, receive
high price, and have healthy farming life. With regards to their perception of contract farming, eachgroup had different reasons. Contract farmers engaged in contract farming because they could receive
stable and high price, learn new techniques, and share experiences with other farmers. On the other
hand, non-contract farmers did not believe on contract farming system, and they preferred to easilysell to many buyers at different prices with no restrictions. For mixed farmers, they engaged incontract farming to learn new techniques but were not sure if their produce will be regularly sold at ahigh price.
CONCLUSION
This research found the existence of three types of farmers, namely contract farmers, non-contract
farmers and mixed farmers. All farmers cultivated organic rice once a year, particularly during wet
season. With regards to crop establishment, direct-seeding was more practiced than transplanting
because of lesser labor requirement. Harvesting was commonly done by hand.
With regards to profitability, all organic rice farmers earned positive total cash income, but
contract farmers got the highest income. In general, contract farmers on both cultivations canincrease their income with higher yield and higher price compared to other farmers. Transplanting
cultivation can produce higher yield but require more labor inputs than direct-seeding. In casefarmers do exchange labor, transplanting can give farmers more profit. In contrast, if there are no
exchange labors, it is better for farmers to do direct-seeding with less labor input.
Although the main reasons for farmers to engage in organic rice were the same (e.g. no
fertilizer expense, receive high price, and have healthy farming life), their perception of contract
farming varied. Contract farmers engaged in contract farming because they could receive stable andhigh price, learn new techniques, and share experiences with other farmers. On the other hand, noncontract farmers did not believe on contract farming system, and they preferred to easily sell tomany buyers at different prices with no restrictions.
For further study, there is a need to assess the existing organic rice certification and contract
farming models, specifically clarify the impact of organic rice contract farming model to smallscale farmers’ livelihoods; and to determine the most suitable organic rice contract farming model.
REFERENCES
Cambodian Organic Agriculture Association. 2011. Organic agriculture and food processing in Cambodia:
Status and potentials. Cambodian Organic Agriculture Association, 5, Cambodia.
MAFF Cambodia. 2016. Annual report 2016. Ministry of Agriculture, Forestry and Fisheries, Cambodia.
Preah Vihear Provincial Department of Agriculture, Forestry and Fishery. 2017. Annual report 2017.
Ministry of Agriculture, Forestry and Fisheries, 9-13, Cambodia.
Rahman, A. Latifunnahar, M. and Alam, M. 2013. Financial management for custom hire service of tractor in
Bangladesh. International Journal of Agricultural and Biological Engineering, 6 (3), 29.
Sa, K. 2011. Organic rice farming systems in Cambodia: Socio-economic impact of smallholder systems in
Takeo Province. International Journal of Environmental and Rural Development, 2 (1), 115-119.
Taing, K. 2008. Economic analysis of organic-culture rice in rural household economy: Case studies in Tram
Kork and Chumkiri district. Master thesis, Royal University of Agriculture, 66-72, Phnom Penh, Cambodia.

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Research article
erd

Economic Performance of Using Combine Harvesters in
Rice Cultivation in Northwest Cambodia
DALIN SUN*
Graduate School of Agriculture, Tokyo University of Agriculture, Japan
Email: da.lin3019@gmail.com

TOMOHIRO UCHIYAMA
Faculty of International Agriculture and Food Studies, Tokyo University of Agriculture, Japan

NINA N. SHIMOGUCHI
Faculty of International Agriculture and Food Studies, Tokyo University of Agriculture, Japan
Received 15 Deember 2018

Accepted 31 October 2019(*Corresponding Author)

Abstract Labor scarcity is the most common problem for Cambodian farmers during
harvesting season since they commonly harvest rice manually. To reduce harvesting loss,
expenses and time, a well-designed combine harvester is gaining popularity. This study
aims to evaluate the economic performance of using combine harvesters in rice cultivation.
Specifically, this study aims to (1) clarify the reasons farmers adopted the use of combine
harvesters, and (2) compare the profitability of rice farming between combine harvester
owner-farmer and non-owner-farmer. This study was conducted in Banan district,Battambang province, where utilization of combine harvesters is prevalent. A total of 68
respondents who use combine harvesters were randomly selected and interviewed using aquestionnaire and further categorized into 34 combine harvester owner-farmers and 34 nonowner-farmers. The study has four main findings. First, most farmers started using combine
harvesters in 2010 due to labor shortage and high wagers. Combine harvester ownerfarmers spent lesser total production cost compared to non-owner-farmers. Second, the total
production cost of both farmer types varied mainly on the variable cost since the nonowner-farmers spent more on rice harvesting fee, while combine harvester owner-farmers
spent only on the cost of diesel, depreciation, and driver. Third, combine harvester ownerfarmers received the higher profitability compared with the other. Fourth, the three main
reasons for adopting the use of combine harvester were labor shortage during peakharvesting season, convenient harvesting on time, and opportunity to provide custom
service to other farmers.
Keywords combine harvester, custom service, cost and return analysis

INTRODUCTION
Rice is the traditional source of income for rural Cambodian people and the essential staple food of
the country and other Asian countries (World Bank, 2014). In general, rice cropping cycle takes
about three months to seven months, depending on the geographical and climate conditions, andrice varieties (CARDI, 2013). Harvesting is an important operation to maintain the productivity andquality of rice which require about labor input of 150-200 man-hours/ha (Salassi and Deliberto,2010). With the advent of industrialization, many agricultural laborers have been moved toindustrial and service sectors or migrated to neighboring countries (Chhim et al., 2015; MAFF
Cambodia, 2016).
Recently, rice harvesting became a relevant issue for farmers due to labor scarcity. Combine
harvesters (CH) have become useful and popular to address the problem of labor shortage inmanual harvesting practices. CH can perform several operations such as harvesting, threshing,cleaning, and discharging grain into a bulk wagon or directly into a bag. Paraweewongwuthi et al.
(2010) and Samaraweera (2012) mentioned that net profit of CH was about 30.3% higher comparedⒸ ISERD

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to manual harvesting and threshing, and there was a significant difference between the average
production costs of CH and manual harvesting methods. Although only limited farmers can afford
to purchase one, many farmers tend to rent CH from other farmers, districts or provinces.
OBJECTIVE
In order to evaluate the economic performance of using CH in rice cultivation, this study aims to(1) clarify the reasons farmers adopted the use of CHs, and (2) compare the profitability of rice
farming between CH owner-farmers and non-owner-farmers.
METHODOLOGYThis study was conducted in Banan district, Battambang province. Located 28 km away from
Battambang city, this district is known as the second largest rice-growing area in the province.
There is also a significantly large number of farmers using combine harvesters. The total area ofthe district is 789 sq. km., of which paddy fields occupy about 43,969 ha (approximately 62% of
total agricultural land) (Banan District, 2016).
Primary data were collected through farm questionnaire survey of randomly selected 68
farmer-respondents and series of key-informant interviews (e.g. district administrator) in Augustand September 2017 in three communes of the district. The farmer-respondents were identified to
be CH users during the time of field survey. They were further equally categorized into 34 CH
owner-farmers and 34 CH non-owner-farmers. Non-owner-farmers refer to those who avail custom
service or rent CH.
Simple descriptive methods and cost and return analysis were utilized.
RESULTS AND DISCUSSION
Characteristics of the Farmer-Respondents
Table 1 General characteristics of farmer-respondents
N
Average family size (persons)Average age (year old)
Average educational level (years)
Average farming experience (years)
Average planted land per HH
Wet season rice (ha)Dry Season rice (ha)CH owner-farmers
34
4
43.6
7.6
16.2

CH non-owner-farmers
34
4
44.0
6.2
13.5

4.4
5.9

2.6
2.4

Source: Field Survey, 2017

In the study, most farmers mentioned that they have engaged in rice farming since they were young
and have made decisions and improvements based on their own experience and knowledge sharedby their ancestors. Although average age of both types was 44 years old, the average educationlevel and years of farming experience of CH owner-farmers were higher than CH non-ownerfarmers. Moreover, with regards to average planted area, CH owner-farmers had larger size forboth wet (4.4 ha) and dry season rice (5.9 ha) than CH non-owner-farmers.
The Reasons for Using Combine Harvester in the Study Area
In relation to CH adoption, field survey revealed that farmers started using CH in 2010 due to labor
shortages during the harvesting period. Moreover, around 90% of the 34 CH owner-farmers
purchased Kubota brand because of its light-weight body, suitability for harvesting rice in both wetⒸ ISERD

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and dry seasons, and affordability. In addition, roughly 25% of CH owner-farmers owned two or
three machines depending on their land size and budget.
Table 2 Main reasons for using combine harvesters
Reason of using CH
Have difficulty in securing hired labor
Conveniently harvest on time
Can provide custom service
Have large farm area
Used by many farmers
Millers do not buy rice harvested by handTotal

CH owner-farmer(n=34)
9
7
10
5
2
1
34

CH non-ownerfarmer (n=34)
10
11
2
3
4
4
34

Total
19
18
12
8
6
5
68

Source: Field Survey, 2017

Table 2 shows the reasons for using CH. The following three main reasons were identified: (1)have difficulty in securing hired labor during peak harvesting season, (2) conveniently harvest on
time, and (3) can provide custom service to other farms. Furthermore, according to interviewed
farmers, family factor highly influenced their decision to purchase or use combine harvesters. The
level of living condition of farmers in rural areas and educational attainment of farmers were low.
Thus, many young people tend to move from rural to urban areas and work in garment factories
and/or other industries or migrate to other countries. Only elderly farmers were left to farm. CH
owner-farmers added that CH was preferred for reducing harvest losses and maintaining rice
quality and quantity. In general, both group farmers showed satisfaction in CH usage.
Rice Production Cost of Studied Farmers in Wet and Dry Seasons
Table 3 Rice production cost of selected farmers in wet season

Land size

Small

Number of HH
Equipment (1)Hand tractor
TractorPumping pipe
Tractor trailer
Combine harvester
Total fixed cost
Cost of seed
Fertilizing
Herbicide
Pesticide
Land preparation fee
Land preparation (fuel)Material input cost (2)Harvesting cost (3)Family labor cost
Hired labor cost
Total variable cost
Total production
cost

2
17.97
66.00
0.00
11.91
0.00
62.67
158.55
39.36
85.27
9.90
9.90
27.23
4.97
7.02
20.38
37.13
15.10
256.26

Wet season (early maturity, 2016)
CH owner-farmers
CH non-owner-farmers
ExtraExtraMedium Large
Small Medium Large
large
large
5
6
5
10
5
4
2
12.81
12.25
11.60
17.52
11.73
12.13
12.16
40.32
38.34
33.70
104.52
80.93
66.49
65.53
69.11
63.29
61.28
0.00
58.96
53.07
48.08
5.82
4.12
3.08
12.49
8.85
6.96
6.67
16.39
14.22
13.64
0
0
0
0
48.02
45.30
39.73
0
0
0
0
192.47177.52 163.03
134.53160.47138.66 132.44
44.95
49.09
49.46
44.45
44.55
48.14
49.01
90.54
97.96 106.53
88.70
90.10
100.73 107.98
11.14
12.38
13.86
10.80
13.61
12.38
12.38
10.02
11.21
12.45
9.41
9.90
10.56
12.38
0.00
0.00
0.00
25.68
0.00
0.00
0.00
20.36
17.15
15.89
4.84
24.36
23.17
21.13
8.61
9.60
10.94
5.29
8.94
10.94
13.95
19.84
19.58
19.46
100.98103.34102.10 100.56
24.94
18.54
13.71
30.40
21.66
19.59
17.82
31.19
43.49
57.10
25.12
34.90
47.65
52.54
261.60279.00 299.40
345.67351.36375.26 387.74

414.81454.07

Items

456.52462.43480.20511.83

Source: Field Survey, 2017
Note 1) Equipment included blue-sheet, sprayer, sickle and sack.
2) Material input cost included cost of pumping water and transportation.
3) Harvesting cost refer to fuel cost of CH owner; harvesting fee of CH non-owner-farmer.
Ⓒ ISERD

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Production cost for early maturity rice and irrigated type rice was calculated by season, farmer typeand operated land size (e.g. small 0.1 to 2.9 ha; medium 3 to 5.9 ha; large 6 to 9.9 ha; extra-large
10 ha and above).
Looking at the rice production cost during wet season by farmer type and operated land size,
production costs of both farm types were correlated with the increase in operated land size (Table3). For example, extra-large CH owner-farmers spent the most, amounting to 462.43 USD/ha,followed by large CH owner-farmers (456.52 USD/ha), medium (454.07 USD/ha) and small(414.81 USD/ha).
However, CH non-owner-farmers seemed to spend more compared to CH owner-farmers. The
significant difference can be attributed to the higher spending of CH non-owner-farmer on
harvesting fee (about 100 USD/ha), while CH owner-farmers spent on diesel, depreciation anddriver fee only.
Table 4 Rice production cost of selected farmers in dry season
Items
Land size

Small

Number of HH
Equipment cost (1)Hand tractor
TractorPumping pipe
Tractor trailer
Combine harvester
Total fixed cost
Cost of seed
Fertilizing
Herbicide
Pesticide
Ploughing (fuel)Material input cost (2)Harvesting cost (3)Family labor cost
Hired labor cost
Total variable cost
Total production cost

3
12.78
44.64
50.04
6.96
19.10
55.13
188.6644.78
112.62
9.90
9.90
19.81
10.43
19.77
28.96
26.61
282.79471.45

Dry season (irrigated type, 2017)
CH owner-farmers
CH non-owner-farmers
ExtraExtraMedium Large
Small Medium Large
large
large
11
9
6
9
10
4
0
13.25
13.06
13.22
14.91
14.53
13.76
38.66
37.43
37.04
77.93
74.44
67.75
45.30
38.31
30.76
61.09
52.94
52.12
5.97
4.11
3.43
9.80
8.75
7.41
18.45
18.06
16.63
0.00
0.00
0.00
51.74
44.79
41.64
0.00
0.00
0.00
173.36
155.76142.73163.73150.66141.05
47.65
48.57
51.98
49.79
50.00
50.31
116.58122.28124.50107.82111.14110.10
12.38
13.00
14.85
12.38
14.85
21.35
10.15
12.38
13.61
12.38
13.61
20.11
19.36
18.51
17.48
22.24
21.39
19.28
11.62
13.58
15.39
9.95
11.15
15.30
19.53
19.27
19.05
74.94
72.40
72.52
20.85
16.24
11.26
32.80
23.39
18.56
41.34
62.38
75.50
26.83
44.62
58.17
299.45326.19343.62349.13362.55385.71472.81481.95486.35512.86513.21526.75-

Source: Field Survey, 2017
Note 1) Equipment cost included blue-sheet, sprayer, sickle and sack.
2) Material input cost included cost of pumping water and transportation.
3) Harvesting cost refer to fuel cost of CH owner; harvesting fee of CH non-owner-farmer.

Unit = USD/ha

Table 4 shows that production cost in dry season rice seemed to be higher than wet season rice
varieties in both farmer type due to shorter cropping duration (only 3 to 4 months) than wet season
rice varieties. In order to achieve higher yield, both farmer types from small to extra-large farmneeded to input more material and labor inputs. Furthermore, farmers who did rice farming withthese varieties spend more diesel cost because they did not do harrowing, but they commonly
plowed twice before direct-seeding. Looking at the labor cost, both farmer types who owned large
and extra-large farms seemed to spend on hired labor cost than small farms, who were likely to doby themselves. CH non-owner-farmers had higher rice production cost than CH owner-farmers ineach category because of the high harvesting fee (around 72 USD/ha).
Rice Farming Profitability of Combine Harvester Owner-Farmers and Non-Owner-FarmersⒸ ISERD

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Net profit of CH owner-farmers and non-owner-farmers in wet season are presented in Table 5.
Average paddy yield of both farmer type ranged from 2.90 ton/ ha to 3.75 ton/ha. The result also
found that extra-large CH owner-farmer gained the highest gross revenue (906 USD/ha) andfollowed by large, small and medium farm. Similarly, extra-large CH non-owner-farmers also
received the highest revenue amounting to 872.90 USD/ha and followed by large (816.60 USD/ha),small (714.57 USD/ha) and medium farm (689.11 USD/ha), respectively.
Looking at the net profit of CH owner-farmers, extra-large farm had the highest amounting to443.65 UDS/ha; and small farm received the lowest profit at 412.47 USD/ha. In addition, small CH
owner-farmer earned almost twice profit than small CH non-owner-farmer.
Table 5 Net profit by type of selected farmers in wet season
Items

CH owner-farmers

Land size

Small

Medium

Large

Number of HH
Paddy yield(ton/ha)
Price (USD/ton)Total cash expense
Total expense
Gross revenue
Gross margin
Net Profit

2
3.75
220.61
338.32414.81827.27488.95412.475
3.30
242.57384.18454.07800.50416.31346.42

6
3.55
249.21388.89456.52883.57494.69427.05

CH non-owner-farmers
Extralarge
5
3.60
251.69399.26462.43906.08506.82443.65

Small

Medium

Large

10
3.10
230.51405.35480.20714.57309.22234.375
2.90
237.62445.62511.83689.11243.49177.284
3.37
241.96446.19513.92816.60370.41302.68Source: Field Survey, 2017

Extralarge
2
3.75
232.77453.35520.18872.90419.55352.71

Unit = USD/ha

Table 6 shows the net profit of CH owner-farmers and non-owner-farmers in dry season. Even,
the group of CH owner-farmers in extra-large farm and large farm seemed likely to spend thehighest amount on total rice production cost than other medium and small farm, but they remained
the highest profit after calculation. Similarly, the group of CH non-owner-farmers in large farm
received 424.53 USD/ha; and followed by medium and small farm. As mentioned earlier, inaverage net profit of CH owner-farmer received the highest profitable compared to net profit ofanother group in each category.
Table 6 Net Profit by type of selected farmers in dry season
Items

CH Owner-Farmers

CH Non-Owner-Farmers

Land size

Small

MediumLarge

ExtraLarge

Number of HH
Paddy yield (ton/ha)
Price (USD/ton)Total cash expense
Total Expense
Gross revenue
Gross margin
Net Profit

3
3.33
232.05397.71471.45773.51375.80302.0711
4.00
235.15404.31472.81940.59536.28467.7894.24
242.78417.14481.951030.47
613.33548.526
4.67
247.03423.11486.351152.81729.69666.45

Source: Field Survey, 2017

Small

Medium

Large

9
3.19
237.28430.27512.86756.92326.65244.0610
3.90
230.82439.82513.21900.19460.37386.974
4.00
237.82457.88526.75951.29493.41424.53ExtraLarge
0--

Unit = USD/ha

In general, in terms of season, farmers who cultivated irrigated rice varieties in dry season
tend to spend higher on total expense than farmers who cultivated wet season rice varieties.
However, irrigated rice varieties had higher yield than other varieties. Moreover, CH non-ownerfarmers had higher rice production cost than CH owner-farmers in each category.
CONCLUSION
Field survey revealed that farmers started using CH in 2010. Kubota was the main CH brand usedin Battambang Province which had an affordable price and was suitable for harvesting during bothⒸ ISERD

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wet and dry seasons. The main reasons for CH adoption were (1) have difficulty in securing hired
labor during peak harvesting season, (2) conveniently harvest on time, and (3) can provide custom
service to other farms. Cost and return analysis revealed that it is more profitable to use CH for
both CH owner-farmers and non-owner-farmers in the study area. Besides, CH owner-farmers
received higher profit in comparison to the non-owner-farmers.
This study recommends that farmers shift to CH usage for rice harvesting in order to address
labor shortage, reduce production cost as well as gain more profit. For further study, there is a needto conduct a detailed study on CH custom services and its social impact on rice farmers’ livelihood.
REFERENCES
Banan District. 2016. Annual report for agriculture of 2016 and direction 2017. Battambang, Cambodia.
CARDI. 2013. Annual report 2013. Cambodia Agricultural Research and Development Institute, Cambodia.
Chhim, C., Buth, B. and Ear, S. 2015. Effect of labor movement on agricultural mechanization in Cambodia.
CDRI, Working Paper, Series No. 107, Phnom Penh, Cambodia.
MAFF Cambodia. 2016. Annual report for agriculture, forestry and fisheries and direction 2000-2015.
Ministry of Agriculture, Foretsry and Fisheries, Phnom Penh, Cambodia.
Praweenwongwuthi, S., Laohasiriwong S. and Rambo A. T. 2010. Impacts of rice combine harvesters on
economic and social of farmers in a village of the Tung Kula Ronghai Region. Research Journal of
Agriculture and Biological Sciences, 6 (6), 778-784.
Salassi, M.S. and Deliberto, M.A. 2010. Estimating rice combine harvester cost: Performance rate, capitalcost, operating cost. Staff Report No. 2010-08.
World Bank. 2014. Cambodia-agriculture in transition. 19-42, 15-22.

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Research article
erd

Developing of Incinerator with Hydrogen Gas
for Hospital Wastes Treatment
KITICHOKE PROMMANEEWAT*
Kasetsart University Chalermphrakiat Sakon Nakhon Province Campus, Thailand
Email: kitichoke.pr@ku.th

SUPALAK SATHIRACHEEWIN
Kasetsart University Chalermphrakiat Sakon Nakhon Province Campus, Thailand
Email: supalak.sat@ku.th
Received 25 December 2018

Accepted 31 October 2019(*Corresponding Author)

Abstract In this experiment, we studied the construction of incinerators using Hydrogengas as fuel in small hospitals. The Hydrogen Gas Incinerating System in this study consistsof 3 major parts, the Water Separation System, Furnace and Combustion System, and the
DC Power Control System. The authors used water mixed with Sodium Bicarbonate(NaHCO3) solution to separate Hydrogen (H) from water by using 12 VDC and 15.50 A
which resulted the 909.09 ml/min of gas flow rate to burn 100 grams of infected waste. The
experiment showed that the waste was completely burnt into ash within 13.35 minutes andthe average power consumption was 0.04 kW-hr. It was concluded that the gas flow rateshould not be less than 800 ml/min because it can have a fire back phenomenon. The result
also showed that the burning cost of waste incineration in this study equaled to 1.50 baht/kg
which was much cheaper than the one of general infected waste in hospital which costs 5
baht/kg.
Keywords electrolysis, medical waste, incinerator

INTRODUCTION
Medical waste with strong infections, toxic and corrosive, emissions, lax management or improper
handling characteristics can cause pollutions to water, atmosphere, and soil and it also makes direct
harm to human body if people do not handle with care (Abah and Ohimain, 2011). In order toensure that the medical waste is in efficient management, harmless to be disposed, and prevent the
spread of disease, scientific research tries to design medical waste treatment machines, which use
high temperature to disinfect and sterilize medical waste and biomass decomposition, and save thecost of transportation which can also create higher economic benefits (Wajs and Golabek, 2019).
However, combustion is a rapid and exothermic reaction between a fuel and oxygen. In
incineration application, the predominant waste is fuel and the oxygen source is air, and the sourcesof combustion can be in many forms of products, whether the materials burned are natural gas, coal,wood, gasoline, hazardous waste, or medical waste which can create pollutions (Allsopp et al.,2001).
Hydrogen fuel is regarded as clean energy. It creates zero-pollution emission when burned
with oxygen. It can be used in electrochemical cells, or internal combustion engines
to power vehicles or electric devices (Bicelli, 1986). Hydrogen energy is a significant alternative
energy. It is as an emerging market for energy business because it creates complete combustion. It
also makes high efficient combustion. The benefit of hydrogen fuel is that it provides more than 2.5
times of hydrocarbon energy. Due to, combustion with hydrogen fuels produces no greenhousegases, smoke, dust, and it is regarded as a conventional energy application. Moreover, theproduction of hydrogen from water by a process called electrolysis has steadily been being
developed (Kudo, 2003).
Therefore, the research team has developed a device called “Dry Cell” to produce hydrogenfrom water which has been applied with a small stove. This small stove can be used to burn
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garbage in small hospitals. The infected waste in many small hospitals at rural areas is removed
unsuitably, or inconveniently to destroy because of long distance. The development of a hydrogenfuel combustion plant, or the Hydrogen Gas Incinerator Plant is an alternative device to decrease
pollution, cost of transportation, and risks from removing waste. The researchers attempt to create aseries of dry cells to produce hydrogen gas as a source of fuel for the medical waste incinerator trial
version machine which there are many factors in the production of hydrogen gas is needed tocontrol. The quantity of hydrogen gas is more or less depending on these variables such as, thedistance between conductance, the electrical current, and the electrolysis method (Kuracina, Fialaand Soldan, 2014). The authors realize the importance of the effectiveness of the medical waste
incinerator which has been desired as a water electrolysis machine, including a pipe line, series ofhydrogen gas and water separating, and slurry filling box in order to get the best performance in theseparation of hydrogen which is used as fuel in combustion infected waste.
OBJECTIVE
The objective is to study the construction of an incinerator using in small hospitals using hydrogenas fuel.
METHODOLOGY
The principle design of medical waste incinerator with hydrogen gas consists of three parts: I, theWater Separation System, using direct current electricity to separate hydrogen and oxygen gas byputting a pure and high quality aluminum electrode plate inside and place in layers. The electrons
flow from the negative terminal of the DC power source to the positive terminal, where they are
consumed by hydrogen ions to form hydrogen atoms. II, the Furnace and Combustion Systems, forburning the waste, and III, the DC Power Control System used for electrical work. The three parts
are described as the followings:
Part I: Water Separation Systems, the general process of water electrolysis, hydrogen ionsmove toward the cathode, whereas hydroxide ions move toward the anode. A secondary
electrochemical cell using aluminum plates as electrode which is drilled for water flowing between
each layer. The insulator is made of rubber cutting edge in every sheet preventing water out of thebox. Aluminum sheets and rubber sheets are arranged alternately as you can see in Fig. 1. It ispressed tightly with screws and nuts enclosed with acrylic plate to prevent water leakage. The tube
is used to connect between the reserved water box and electrolysis box. Hydrogen gas fromsplitting water by electrolysis procedure then it flows into the reserved water box and flows to the
air filtration set. The water inside the reserved water box will flow into the dry cell or electrolysis
box. As a result, the water inside the box is full at all the time. Because this design does not have agas separating type. The gas in electrolysis procedure is a mixture of hydrogen and oxygen which
is used as a fuel. It will pass through a one-way pipe towards the following combustion systems.

Fig. 1 Hydrogen gas production equipmentⒸ ISERD

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Part II: The Furnace and Combustion System consists of a furnace box frame inside which islined with refractory brick and has steel mesh to allow the ash fall into the bottom. The furnaceside is drilled to connect to the pipe with jet valve type to deliver hydrogen and oxygen. To prevent
fire back phenomena, the check valve has been installed for controlling the direction of the gas
flow. The jet valve is also connected to the spark plug for ignition to burn the garbage.
Part III: The Control System which is for electrical work consists of a 220 VAC switching to a
12 VDC 50 A for power supply. The electrical energy is shown by the voltmeter and the current
meter equipment which is supplied to two devices. The first batch of electrical energy supplied toan electrolysis unit is controlled by electric control circuit. The second one is supplied to a set ofthe sparking that the circuit generates a high frequency and high power for transmission toautomotive spark plugs. The pipeline design in all 3 parts can be simplified as illustrated in Fig. 2.

Fig. 2 The pipeline design of the incinerator
1. Hydrogen gas pipeline
2. Water level measuring tube box
3. Cable Anode wire
4. Cable Cathode wire

5. Power supply pipeline
6. Water supply pipeline
7. Drain tube
8. Water and slurry filling pipe

Fig. 3 The hydrogen gas incinerator plant with 3 sections
RESULTS AND DISCUSSION
In the electrolysis process, the separation efficiency of gas with electricity depends on different
variables: the spacing of the electrode plate, size of the electrode plate, voltage and electrolyte
solution. The quantity of hydrogen gas is proportional to the inverse of the distance betweenⒸ ISERD

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electrodes, while the size of the electrode plate voltage and the concentration of the electrolyte
solution is proportional to the quantity of gas. The distance between the plates sheet was set as
close as possible at the range of 0.1 mm. The size of the conduct sheet using 22x22 cm. The supply
voltage is 12 VDC. Use sodium bicarbonate (Na2CO3) amount of 300 grams in 1 lite of water toprepare of electrolyte solution. The results showed that default value of electricity is quite low as
about 10 A when the supply 12 VDC was applied. Initial temperature of water is equal to thetemperature of water at room temperature. When the process of electrolysis occurs, water will bechange into hydrogen and oxygen gas. This process is exothermic, the temperature of the water isincreased, as a result, the electrical resistance is dropped. Consequently, the electric current
increases, the rate of gas will also increase. It can be interpreted as the rate of gas that produced is
proportional to the voltage and the temperature rise as shown in the Table 1.
Table 1 The flow rate of hydrogen and oxygen
Current (A.)

Temperature of water (°C)

Gas flow rate (mm³/min)

11

33.0

432.9012

35.0

492.61

13

40.0

699.3014

44.0

769.231545.6

909.0916

47.0

942.4017

48.0

956.7018

48.5

977.5019

48.7

982.3020

48.7

990.40Although the flow rate of gas is increased according to the value of electrical current, the rateis stable when it reaches the value of electrical current at 15A as shown in Fig. 4, where the flowrate of mixing gas value is close to 1,000 mm3/min.

Fig. 4 The Plot between the Rate of gas flow and current
The infectious dry waste in quantity of 100 grams of cotton, gauze and bandage were selectedin the experiment. A measurable 12 VDC voltage and an average current of 15.50 A were selected.
It was found that the incinerator was able to burn 100 grams of dry waste within 13.35 minutes, andthe average power consumption is 0.04 kW-hr.

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Table 2 Results by burning dry infectious waste incinerators
No.

Current (A.)

Time (Minute)

Average Power(Watt)

Energy(kW-hr)

1

15.0

13.37

216.2

0.04

2

15.1

13.37

216.3

0.04

3

15.5

13.35

216.6

0.04

4

15.7

13.34

216.6

0.04

5

16.0

13.33

216.7

0.04

The infectious wet waste quantity of 100 grams of cotton, gauze and bandage with humidity at
85% were selected in the experiment. A measurable 12 VDC voltage and average current of 15.1 A
were selected. It was found that the incinerator was able to burn 100 grams of wet waste
within17.40 minutes, and the average power consumption is 0.07 kW-hr.
Table 3 Results by burning wet infectious waste incinerators
No.

Current (A.)

Time (Minute)

Average Power(Watt)

Energy(kW-hr)

1

15.0

17.36

223.2

0.07

2

15.1

17.36

223.1

0.07

3

15.0

17.41

223.1

0.07

4

15.1

17.40

223.2

0.07

5

14.5

17.44

223.4

0.07

CONCLUSION
From the production of medical waste incinerator using energy from hydrogen and oxygen fromwater separation process, it was found that the quantity of electricity flowing through the electrodesheet varies to the water temperature. The water resistance is inversely proportional to thetemperature. The gas mixture of hydrogen and oxygen used to burn the garbage which shows theapproximately minimum gas flow rate should be not less than 800 ml/min. If the flow rate is lessthan this value, it can have a fire back phenomenon. In addition, the results showed that dry waste
consumed less double energy than wet waste as shown in Tables 2 and 3. When calculating the costof electricity, it was found that the average power for burning dry waste is about 0.04 kW-hr, whileburning the wet waste is 0.07 kW-hr respectively. The result also showed that the burning cost of
infectious dry waste equaled 1.50 baht/kg, however the medical infectious incineration method in
general hospital cost 5 baht / kg.
ACKNOWLEDGEMENTS
The authors are thankful to the Faculty of Science and Engineering, Kasetsart University
Chalermprakiat Sakon Nakhon Province Campus for providing financial assistance to carry out thiswork.
REFERENCES
Abah, S.O. and Ohimain, E.I. 2011. Healthcare waste management in Nigeria: A case study. Journal of
Public Health & Epidemiology, 3 (3), 99-110.
Allsopp, M., Costner, P. and Johnston, P. 2001. Incineration and human health: State of knowledge of the
impacts of waste incinerators on human health. Environmental science and pollution researchInternational, 8 (2), 141-145.
Kudo. A. 2003. Photocatalyst materials for water splitting. Catalysis Surveys from Asia, 7 (1), 31-38.
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Kuracina, M., Fiala, J. and Soldan, M. 2014. Study of selected characteristics of a dry cell hydrogengenerator in condition of long term operation. Advanced Materials Research, 1001, 109-113.
Peraldo Bicelli, L. 1986. Hydrogen: A clean energy source. International Journal of Hydrogen Energy, 11 (9),555-562.
Wajs, J., Bochniak, R. and Golabek, A. 2019. Proposal of a mobile medical waste incinerator withapplication of automatic waste feeder and heat recovery system as a novelty in Poland. Sustainability,
MDPI, 11 (18), 1-18.

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Research article
erdPhysicochemicals Properties of Soils with Peanut Shell
Amendment and Its Impact to Growth and Yield of Maize
NYO NYO WIN*
Department of Chemistry, Myitkyina University, Myitkyina, Myanmar
Email: nyonyowin364@gmail.com

THIDAR KHAING
Department of Chemistry, University of Mandalay, Mandalay, Myanmar

SUU SUU WIN
Department of Chemistry, Kalay University, Kalay, Myanmar
Received 12 February 2019

Accepted 30 November 2019(*Corresponding Author)

Abstract The present research studied how the addition of peanut shell to the soil effectedon physicochemical properties of soil and plant growth. Waste peanut shells were used toenhance soil properties by composting for cultivation of plants as the organic fertilizer. In
the composting step, 2:3 (v/v) of peanut shell and soil was mixed for two months andutilized for the cultivation of maize plants. Some parameters of soil, peanut shell and peanut
shell-compost such as pH, moisture, nitrogen, phosphorus, potassium, organic carbon, total
sulphur, calcium and magnesium were examined by using their respective standard methods
to compare the properties of control and compost-soil. It is observed that the soil addedwith peanut shell-compost has a potential increasement of nitrogen, phosphorous,
potassium, total sulphur, total calcium and total magnesium in plant growth media thancontrol soil. The results obtained in plant growth media also pointed out that the growth rate
and yield percent with composed soil were better than those of control soil. These researchfindings can contribute to the local people from agricultural field with the scientificinformation of waste peanut shell as low cost alternative fertilizer.
Keywords physicochemical properties, soil, peanut shell, peanut shell fertilizer

INTRODUCTION
Soil quality is the capacity of a soil to a function and this function balances the physical, biological,
and chemical components of soil (Karlen et al., 1997). Soil physical properties can give a profoundeffect on how soils influence soil quality and productivity. Soil quality level is improved by soil
physical properties that measure nutrient and moisture present in soils. The physical properties ofsoil contain soil texture, bulk density, water holding capacity, organic matter content, soil structure,soil color, and soil consistence (Schoeneberger et al., 2012). By adding organic compost to soil
before planting gives the soil the boost in nutrients plants depend upon to grow. Fertilizers added
later help provide the plants to use nutrients well. Various organic fertilizers amend the soil,
including manure, blood meal and wood ash. Among organic materials, peanut shell also has few
beneficial minerals plants can absorb and are best use as a protective covering. The beneficial
effects on crop production are found and soil properties are directly related to the physical,
chemical and biological properties of the composts used (He et al., 1995). Application of organic
manures (sewage sludge, compost, manure) in a heavy soil aggregation support porosity,
permeability, and air and also in sandy soil to hold water and nutrients help (Abusharer, 1996).

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OBJECTIVE
This study focused on the changes in the chemical properties of soil prepared by applying during
aerobic decomposition and the plant growth.
METHODOLOGY
Sample Collection
Surface soil samples were collected from farmland of Changgyi Village, Tha- beik- kyin Township,
Mandalay region in Myanmar. Peanut shells were collected from peanut shell factory, Mandalay
Industrial Zone and they were crushed into small pieces and used as the organic fertilizer for maize
plants.
Preparation of Peanut Shell Fertilizer
The combined ratio of peanut shell and soil 2:3 v/v were mixed. The composting process was
initialized by preparation of the compost container with suitable size of plastic basket making fivesmall holes in the bottom. During composting process, combined sample was turned periodicallyfor better aeration. After composting 2 months, soil color was found as dark color because of thedecomposition of waste materials into the soil.
Determination of Soil Texture
Soil samples (before and after plantation) of texture were analyzed at Department of Agriculture(land use) of Yangon, Myanmar by pipette method (AOAC International, 1999).
Determination of Physicochemical Properties of Three Samples
Determination of pH:
A mixture of air-dried sample and water (1:5) was placed in a 50 mL shaking bottle and shaken
vigorously for 5 minutes. The pH of soil suspension was measured with a pH meter (F-51,
HORIBA).
Determination of moisture:
The sample was allowed to dry in an electric oven at 105°C, cooled in desiccators and weighed. It
was repeated until the constant weight was obtained. From the loss in weight, the percentage ofmoisture in the sample is calculated (AOAC International, 1999).
Determination of total nitrogen:
The sample at 0.5 g was put in 600 mL digestion tube and added 1 g of catalyst and then it is gently
heated until frothing ceases. The flask was removed from the heater and cooled, added distilledwater and transferred to the suitable volumetric flask. Accurately 20-25 mL of 2% boric acid wasplaced in and methyl the receiving conical flask red indicator (2-3) drops was added. Enough water
was added to cover the end of the condenser outlet tube. 5 mL of aliquot was pipetted into the
distillation tube and 25 mL of 40% NaOH was added and was distilled for about 4 minutes. The
receiving flask was removed and the outlet tube was rinsed into the receiving flask with a small
amount of distilled water. The ammonia distillate was titrated with excess acid 0.02 N H2SO4. The
blank was determined in the same manner (AOAC International, 1999).
Determination of total phosphorous:
Aliquot (5-25 mL) depending on phosphorus content was pipetted in a 50 mL volumetric flask andadded 5 mL of Barton's Reagent and diluted to 50 mL with distilled water. After 1hour, it wasmeasured with spectrophotometer at 420 nm (AOAC International, 1999).
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Determination of available phosphorous:
Air-dried sample at 2 g was weighed and placed in a 500 mL shaking bottle. A 400 mL of buffer
solution was poured into the flask and the contents were shaken for 30 minutes. And then it was
filtered and 50 mL of extract was pipetted into a 100 mL volumetric flask. Three drops of saturated
2,4 dinitrophenol, 4 mL of 2.5% sulphomolybdic acid solution and 6 drops of freshly preparedchlorostannous acid reductant were added to the solution. The solution was made up to 100 mL
with distilled water. The amount of P2O5 was determined spectrophotometrically at 660 nm andcalibration curve set up employing the standard solution was used to determine to P 2O5 in the soil
(AOAC International, 1999).
Determination of total potassium:
The sample (5 g) was heated in a pre-weighed porcelain crucible by heating slowly without
combustion. Then the crucible was placed in the furnace at 550°C for 16 h till a white ash of
constant weight was obtained. The ash (0.1 g) was digested for 5 minutes with 2 mL ofconcentrated hydrochloric acid in a beaker. Then, it was dissolved in 16 mL of 25% hydrochloric
acid solution by warming on a water bath for a few minutes. Then it was transferred to a 100 mL
volumetric flask and the volume to the mark with distillated water (AOAC International, 1999).
Determination of available potassium:
Air-dried sample at 5 g was placed in a 100 mL shaking bottle containing 50 mL of 1 M
ammonium acetate solution. It was shaken for 1 h and filtered. Available K 2O was determined on
the filtrate by using a flame photometer (AOAC International, 1999).
Determination of organic matter:
The sample was ash at 500-600°C by placing a suitable weight (0.5-1.0 g) of the sample in a silica
crucible and heating it in a muffle furnace for 4-6 h. Loss of weigh on ignition can be used as adirect measure of the Organic Matter (MO) (AOAC International, 1999).
Determination of total sulphur:Aliquot (2-5 mL) was taken in 50 mL volumetric flask. Acetic acid 50% (5 mL), Gum acacia
0.25% (2 mL) and (1 mL) of orthophosphoric acid were added into this flask and then was shaken
for 1 minute. The volume was made up to 50 mL with distillated water and measured the turbidity
at 440 nm (AOAC International, 1999).
Determination of total calcium and magnesium:
The stock standards in concentration of 1000 ppm is prepared from pure metal wire, granules, foil,
metal oxide or other suitable primary standard compounds of the elements. A calibration curve wasapplying by recording the absorbance of a series of working standards. The calibration must be
done for each set of analysis. Aliquot is taken depending on concentration in a 50 mL volumetricflask and added 5 mL of strontium chloride and dilute 50 mL with distilled water. The content ofelement is determined from the standard curve (AOAC International, 1999).
Plantation of Maize on Soil Samples
The peanut shells were used as natural-based biofertilizer in the plantation of maize. The maizegrains were sowed into the soil that placed in the plastic bags and these bags were regularly watered.
After 7 days, the germination of maize grains occurred. Then the high of the nursery plants were about 2
to 2½ inches, they were picked out and transferred to specially prepared roles for plantation experiment.
Each same size 10 plants were cultivated in soil without treatment as control and treatment with thepeanut shell. A row has 10 ft length and 1 ft width. Comparison of the maize plants in the control soil
and treated soil were done after one month, two months, three months and four months and they wereshown in Fig. 1 and the height of maize plants were determined.
Determination of Maize Height and YieldⒸ ISERD

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The height of plant were measured at the end of four months, the time of harvest and the yieldpercent was determined based upon the total weight of maize samples.

After one month(control)After one month(treatment)

After two month(control)After two month(treatment)

After three month(control)After three month(treatment)

After four month(control)After four month(treatment)

Fig. 1 Comparison of the maize growth in the untreated and treated soil
RESULTS AND DISCUSSION
Soil Texture Before and After Treatment
The texture contents of soil samples before and after treatment were measured and the results
obtained shown in Table 1.
Table 1 Soil texture before and after treatment
SampleBeforetreatment
Aftertreatment

Sand (%)

Silt (%)

TextureClay (%)

Total

76.76

9.36

13.88

100.00

Sandy loam

70.76

18.36

10.88

100.00

Sandy loam

RemarkAccording to Table 1, while the soil before treatment contains sand 76.76%, silt 9.36% andclay 13.88%, the soil after treatment possesses sand 70.76%, silt 18.36 and clay 10.88% andtherefore these two soils lie in the sandy loam texture. Double amount of silt percent in treated soil
sample inform that it is more suitable for plant crop.
Some Physicochemical Properties of Untreated Soil, Treated Soil and Peanut Shell
From the experimental results, pH, moisture, organic matter, nitrogen, phosphorous, potassium,
sulphur, calcium and magnesium of samples were listed in Table 2.
According to the results, the values pH in peanut shell (6.62), soil sample (6.49) and peanut
shell fertilizer (6.75) were found to be consistent with the recommended pH level of soil according
to the National Gardening Association, i.e., pH values between 5.8 and 6.8 (Thermo Fisher
Scientific, 2013). Chemical constituents of peanut shell told the reason of higher level of soil
nitrogen, phosphorous, potassium and organic carbon after composting due to the acceptance ofⒸ ISERD

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nutrients released from the peanut shells. Nitrogen content increased with the amount of peanut
shell composed applied, which is due to high the increased amount of nitrogen was found in thetreated soil by applying compost which include nitrogen abundant peanut shell. Moreover similareffects were resulted as better responses in total sulphur (640.5 mg/kg), total calcium (1.44%) andtotal magnesium (1.51%) contents in the treated soil sample than the untreated one.
Table 2 Physicochemical properties of three tested samples
Parameter

Unit

pH
Moisture
Total nitrogen
Total Phosphorous
Available Phosphorous
Total Potassium
Available Potassium
Organic carbon
Total sulphur
Total calcium
Total magnesium

%
%
%
%
%
%
%
mg/kg
%
%

Untreated soil
sample
6.49
4.29
0.14
0.87
0.25
0.59
3.07
20.67
605.0
0.91
1.35

SamplesTreated soil
sample
6.75
5.87
1.16
0.67
0.43
1.48
3.66
39.01
640.5
1.44
1.51

Peanut shell
6.62
10.98
1.26
1.57
0.01
0.78
3.00
30.00
140.0
0.27
0.32

The Effect of Natural Fertilizer on the Maize Growth
The effect of natural fertilizer on the maize growth was determined by applying two indicators,
plant height and maize yield and the results obtained were shown Fig. 2.

Maize grains from treated soil

Maize grains from untreated soil

Fig. 2 Comparison of the yield of maize grains
Table 3 Comparative effect of untreated and treated soil on plant height and maize yield
Untreated soil

Peanut shell compost

Plant height

150 cm165 cmMaize yield(No of maize/plant)

38 %

45 %

As shown in the Table 3, the plant height and yield of maize grain were measured at the end offour months and Compost organic materials led to better qualities to the soil as compared with thesoil without compost. These results are in accordance with the literature values (Badar et al., 2015).
And then the soil prepared with peanut shell also render slightly better growth rate of plant height(165 cm) than that of untreated soil (150 cm).
CONCLUSION
Peanut shell-compost led to increased amount of physicochemical properties of soil, improvementin plant growth and yield. According to the research studies, the peanut shell-compost had potentialⒸ ISERD

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effect on soil especially for the enhancement of essential nutrients. It seems that peanut shell
cellulose tissue can create the suitable size of nourishing compost particles and high porosity andthese facts can provide high maize yield. The results obtained showed that providing peanut shellcompost as natural fertilizer was an appropriate method to enhance the plant nutrients and growth.
It is consistent with environmental standard and recommendation that peanut shell-compost issuitable in the plant growth media and can be applied as a recycled material in the agriculture.
ACKNOWLEDGEMENTS
I wish to express my thanks to Rector Dr. Aung Win, Pro-rectors Dr. Soe Myint Aye and Dr. Aye
Aye Ko, and Professor Dr. Ni Ni Aung (Head of Professor), Dr. Nant Si Si Htay (Professor,
Department of Chemistry, Myitkyina University) for their kind encouragement.
REFERENCES
Abusharer, T.M. 1996. Modification of hydraulic properties of a semiarid soil in relation to seasonal
application of sewage sludge and electrolyte producing compounds. Soil Technology, 9, 1-13.
AOAC. 2005. Official Methods of Analysis. 18th edn, Association of Official Analytical Chemists, Arlington,
VA., USA.
Badar R., Khan M., Batool B. and Shabbir S. 2015. Effects of organic amendments in comparison withchemical fertilizer on cowpea growth. International Journal of Applied Research, 1 (5), 66-71.
He, X.T., Logan, T. and Traina, S.J. 1995. Physical and chemical characteristics of selected municipal solid
waste composts. Journal Environmental Quality, 24, 543-552.
Karlen, D.L., Mausbach, M.J., Doran, J.W., Cline, R.G., Harris, R.F. and Schuman, G.E. 1997. Soil quality:
A concept, definition, and framework for evaluation (A Guest Editorial). Soil Science Society of America
Journal, 61, 4-10.
Sanchez-Monedero, M., Roig, A., Cegarra, J., Bernal, M.P., Noguera, P. and Abad, M. 2004. Composts as
media constituents for vegetable transplant production. Compost Science utilization, 12, 161-168.
Schoeneberger, P.J., Wysocki, D.A., Benham, E.C. and Soil Survey Staff. 2012. Field book for describing
and sampling soils. Version 3.0, Natural Resources Conservation Service, National Soil Survey Center,
SSSA, USA.
Thermo Fisher Scientific (n.d.). 2013. Gardening & soil pH. Retrived from ww.eutechinst.com/tips/ph/15soil-ph.pdfⒸ ISERD

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Research article
erd

The Stream Flow and Water Level Change on Mekong
Mainstream from the Hydropower Development Projects at
Nakhon Panom, Thailand
THODSAPOL CHATURABUL*
Faculty of Science and Engineering, Kasetsart University Chalermphrakiat Sakonnakhon
Province Campus, Sakonnakhon, Thailand
Email: thodsapol.ch@ku.th

THANAPORN SUPRIYASILP
Faculty of Engineering, Chiang Mai University, Chiangmai, Thailand

KOBKIAT PONGPUT
Faculty of Engineering, Kasetsart University, Bangkok, Thailand
Received 5 January 2019

Accepted 30 November 2019(*Corresponding Author)

Abstract Mekong, a major trans-boundary river, is one of the main source of hydropower
for many Southeast Asian countries. Sources of the hydropower come from many megadams along the river. However, constructing mega-dams for hydropower causes numbers ofhydrological effect especially with the change of water flow and water level along the river.
Nakhon Panom, a province located by the river bank in Thailand, has been severely
affected by the hydropower dam operation. To solve these dilemmas effectively, a set of
up-to-date data from all perspectives is need for the analysis, however, the data that reports
on a transition of hydrological after dam construction are currently limited. This study aims
to respond the needs of data by investigate the change of water flow and water level before
and after the dam construction using various indicators under the principle of Indicators ofHydrological Alteration (IHA). Hydropower project timeline was created to analyze thedaily discharge and water level from 1964 to 2013. Findings portrayed that the water flow
had been significantly changing and may directly affects people along Mekong River interms of their livelihoods, agriculture and tourism activities (e.g. Songkran Festival). The
results of this study also can be used as a reference data for hydrological analysis in the
future.
Keywords Mekong mainstream, hydropower, hydrological impact, transboundary impact

INTRODUCTION
Mekong River is a major trans-boundary river in Asia which has a lot of potential for hydropower
development. The river can be divided into two parts: the Upper Mekong from Tibetan Plateau andChina where it is named Lancang Jiang and passing Yunnan province of China and Myanmar, andcontinues the flow through the Lower-Mekong passing Thailand, Laos, Cambodia and Vietnam(Fig. 1a)
The Upper Basin covers 24 percent of the total area and contributes 15 to 20% of the waterthat flows into the Mekong River. Most of the total flow volume is delivered to the Mekong fromtributaries in the Lower Mekong Basin. These tributaries can be separated into two groups:
tributaries on the left bank that drain the high-rainfall areas of Lao PDR to the major wet season
flows, and tributaries on the right bank, mainly the Mun and Chi rivers, that drain low relief regionsof lower rainfall a large part of Northeast Thailand. The major contribution comes from the two
major ‘left-bank’ (eastern) tributaries between Vientiane–Nakhon Phanom and Pakse-Stung Trengthat together contribute more than 40% of the flow (Table 1 and Fig. 1b). These two groups oftributaries are also marked by different levels of resource development i.e. in Thailand there is littleⒸ ISERD

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room for further expansion of irrigation development and in Lao PDR, there is a lot of potential forwater resources development of all kinds (MRC, 2005; 2007; 2018).
Nakorn Panom, one of eight provinces of Thailand, is directly affected from the operation ofhydropower projects in both Mekong mainstream and its branches.
The Upper Basin makes up 31% of the water that flows through Nakhon Panom. While thetributaries during Vientiane – Nakhon Phanom contribute 22% of the flow as shown in Table 1.
Table 1 Proportional contributions to total Mekong River flow
River Reach
China
China – Chiang Saen
Chiang Saen – Luang Prabang
Luang Prabang – Vientiane
Vientiane – Nakhon Phanom
Nakhon Phanom – Mukdahan
Mukdahan – Pakse
Pakse – Kratie
Tonle Sap
Total

Left Bank (%)

Right Bank (%)
16

1
6
1
18
3
4
22

3
2
2
4
1
6
2
9

55

20

Total (%)
16
4
8
3
22
4
10
24
9
100

Source: MRC (2018)(a) Overview (Rossi et al., 2009)(b) Major contributions to flow (MRC, 2009; 2018)

Fig. 1 Mekong River and its characteristics
Currently, the mainstream in China is dammed by 6 hydropower projects in planned cascadeof up to eight storage hydropower projects i.e. Xiaowan Dam, Jinghong Dam, Dachaoshan Dam,
Manwan Dam, Nuozhadu Dam and Gongguoqiao Dam. While the first dam of 10 proposed run-ofriver hydropower projects in Lower Mekong River i.e. Xayaburi Dam is under construction.
Moreover, most Mekong River tributaries have cascades of dams in place or planned (MRC, 2010).
Mega-dam structure construction usually results in huge hydrological effect regarding thewater flow and water level. This alteration also causes worrisome to people along the river aboutⒸ ISERD

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the direct and indirect impacts to their livelihoods in terms of their small-scaled fisheries, theeconomic system and the ecology system of the river.
From the above-mentioned consequences, the monitoring system of transboundary impacts
should be established to monitor the impact prior to the construction, during the construction
process and after the construction has finished.
OBJECTIVE
The objective of this research is to investigate the result of pre and post constructing the dams
using various indicators under the principle of Indicators of Hydrological Alteration (IHA) in
Nakhon Panom province, Thailand.
METHODOLOGYThe Indicators of Hydrologic Alteration (IHA) model is used to provide information to understandthe hydrologic impacts of human activities as a result of the dam construction. This model cancalculate 67 statistical parameters that later are subdivided into 2 groups i.e. 33 IHA Parametersand 34 Environmental Flow Component (EFC) parameters. For IHA parameters, it can becalculated using parametric (mean/standard deviation) or non-parametric (percentile) statistics.
(Nature Conservancy, 2009).
Daily time series of discharge and water levels from 1964 to 2013 from provided by Thailand
National Mekong Committee were used to investigate the results of pre and post dam construction
using various indicators from IHA by Nature Conservancy (2009), and indicators from the studies
of Piman (2013) and World Bank (2004).
In this study, the time duration was divided into four phases depending mainly on theoperations of the two dams locating on the Upper part of Mekong River: Dachaoshan Dam (2003);
Manwan Dam (1996) and two dams on the tributaries: Nam Ngum Dam (1972); and TheunHinboun Dam (1998). The water flow status and the water level in the past before dam operation
was likely in its natural condition however, natural flow of the mainstream water was changed
because of the dam construction (2014) as illustrated in Fig. 2.
Daily discharge andwater levels
from 1964 to 2013

Indicators ofHydrological
Alteration model
(IHA)

Input

Model simulation

Four scenarios
Dachaoshan
dam (2003)

Manwan dam(1996)

Nam Ngumdam (1972)

Theun-Hinboun
dam (1998)

Results

Monthly Analysis
Flow and Water
Level Alteration

Annual Analysis

Coefficient ofdispersion change

Flow and Water Level Alteration

Fig. 2 Study diagramⒸ ISERD

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RESULTS AND DISCUSSION
Monthly Flow and Water Level Analysis
The analysis of mean monthly flow and mean monthly water level illustrated that under the dam
construction and operation, most of the dam contribute to increasing the water flow and water levelin every month except Nam Ngum Dam in which the flow and the water level are decreased in
July, August, and December (Figs. 3 and 4). These might cause from the operation of Nam Ngum
dam in Nam Ngum River, Laos PDR which diverse the water to Se Bang Fai River (opposite
Nakhon Phanom province). The flow had increased more than 30 percent after the constructions in
April and May. This alteration is different from other areas in Thailand which the flow is usually
increase during dry season and decrease during wet season. The highest flow alteration is 50.35%
in April resulted from the Theun-Hinboun Dam. The highest change of flow variation found inJune with the 150.81% change in coefficient of dispersion (CD) resulted from Nam Ngum Dam(Fig. 3).
In terms of water level, the highest water level alterations is 58.22% in April which resulted
from Manwan Dam, while Theun-Hinboun Dam contributed 49.71% of the change. The highest
change of water level variation is still found in June with the 135.48% of CD change resulted from
Nam Ngum Dam (Fig. 4). Moreover, it was found that during March to May and July, the monthly
water level was also increased.

(a) Flow alteration(b) Change of coefficient of dispersion
Fig. 3 Monthly flow analysis(a) Water level alteration(b) Change of coefficient of dispersion

Fig. 4 Monthly water level analysisⒸ ISERD

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However the characteristic of the average monthly flow graphs from Nakhon Phanom wasincreased every month and showed the differences when comparing to the stations from the
upstream (see Piman, 2013; Lu et al, 2014; Rossi et al, 2009) which average monthly flow
increased in dry-season and decreased in wet-season.
Annual Flow and Water Levels Analysis
The annual flow analysis indicated that the operation of dams had significantly increased meanannual flow in Mekong mainstream except Nam Ngum dam. Theun-Hinboun dam contributes themost effect to the flow. The mean annual discharge before and after dam operation is 6,810 and
8,390 m3/s, respectively (Fig. 5). The annual flow after dam operation has 1,580 m3/s increased.
While the annual water level analysis showed that the operation of dams just slightly increases
the water level. The highest increment of water level is 0.04 m resulted from Nam Ngum Dam andDachaochan Dam.

(a) Nam Ngum Dam(b) Manwan Dam(c) Theun-Hinboun Dam(d) Dachaoshan Dam

Fig. 5 Annual flow analysis
CONCLUSION
A construction of the mega-dam structure in hydropower project usually results in hugehydrological effect regarding flow and water level. In Nakhon Phanom, the water level was highly
increased as a result of the water releasing from hydropower projects from Nam Ngum, and TheunHinboun project in Laos.
The monthly flow and water level analysis indicated that most of the dams contribute toincrease the flow and water level every month except Nam Ngum dam that the flow and the waterlevel decreases in July, August, and December. The highest flow alteration is 50.35% found in
April resulted from Theun-Hinboun Dam. The highest change of flow variation found in June wasⒸ ISERD

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150.81% change in coefficient of dispersion (CD) resulted from Nam Ngum Dam whereas thehighest water level alteration is 58.22% found in April which resulted from Manwan Dam.
The annual flow and water level analysis indicated that the operation of dams significantly
increased mean annual flow in Mekong mainstream except Nam Ngum Dam. Theun-Hinboun Dam
influenced the water flow the most. The annual flow after dam operation was increased to 1,580
m3/s. While the annual water level analysis showed that the dam operations have slightly effect tothe increasing of water level. The highest increment of water level is 0.04 m. resulted from Nam
Ngum Dam and Dachaochan Dam.
To handle with the occurrences, communities along Mekong River need to adapt themselvesto the changes. Additionally, Thailand should be more actively collaborated with other countries
especially for their assistance to supply the water when needed. Further studies need to be
conducted regarding the hydrodynamic model to calculate the length of time from the releasing
points and the preferred destinations.
ACKNOWLEDGEMENTS
This paper was originated from “The Study and Monitoring of Transboundary Environmental
Impact towards the Development of Hydropower Projects in Mekong Mainstream” by Thai
National Mekong Committee (TNMC), Department of Water Resources, Thailand.
The authors would like to thank Faculty of Science and Engineering, Kasetsart University
Chalermphrakiat Sakonnakhon Province Campus, Thailand for the research fund and also thank toMiss Tasaporn Wetcharoen, Miss Mattika Khamchoo and Miss Ornuma Phong Sinsu for theircontributions to this paper.
REFERENCES
Lu, X.X., Li, S., Kummu, M., Padawangi, R. and Wang, J.J. 2014. Observed changes in the water ﬂow at
Chiang Saen in the lower Mekong: Impacts of Chinese dams? Quaternary International, 336, 145-157.
MRC. 2005. Overview of the Hydrology of the Mekong Basin. Mekong River Commission, Laos PDR.
MRC. 2007. Presentation on flow contribution to the Mekong mainstream (1985-2000-using DSF). The 7th
Meeting of the Technical Working Group, Mekong River Commission, Vientiane, Laos PDR.
MRC. 2009. The flow of the Mekong. MRC Management Information Booklet Series No. 2, Mekong River
Commission, Laos PDR.
MRC. 2010. Initiative on sustainable hydropower (ISH) 2011-2015 Document. Mekong River Commission,
Laos PDR.
MRC. 2018. Mekong Basin, hydrology. Mekong River Commission for Sustainable Development, MekongRiver Commission, Laos PDR.
Nature Conservancy. 2009. Indicators of hydrologic alteration. Version 7.1 User’s Manual, Nature
Conservancy, USA.
Piman, T., Cochrane, T.A., Arias, M.E., Green, A. and Dat, N.D. 2013. Assessment of flow changes fromhydropower development and operations in Sekong, Sesan, and Srepok Rivers of the Mekong Basin.
Journal of Water Resources Planning and Management, 139, 723-732.
Rossi, C.G., Srinivasan, R., Jirayoot, K., Le Duc, T., Souvannabouth, P., Binh, N. and Gassman, P.W. 2009.
Hydrological evaluation of the lower Mekong River Basin with the soil and water assessment tool model.
International Agricultural Engineering, 18 (1-2), 1-13.
World Bank. 2004. Modelled observations on development scenarios in the lower Mekong Basin. Mekong
Regional Water Resources Assistance Strategy, World Bank, 41-54.

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erdInternational Society ofEnvironmental and Rural Development

Philosophy of ISERD:
Recently, in developing countries, subsistence agriculture is being converted to export-oriented mono-culture,and the amounts of agricultural chemicals applied to the farmland are increasing every year. The appliedchemicals in farmland cause serious environmental problems downstream such as eutrophication, unusual
growth of aquatic plants, decrease in dissolved oxygen and accumulation of bottom mud in water resources.
Also, there seem to be many cases in which people apply agricultural chemicals without understanding its
impact to health and food safety. Therefore, it is necessary to promote and enhance understanding ofsustainable rural development among local stakeholders including farmers.
Sustainable rural development aims to meet human needs while preserving the natural environment. As
it should cover not only social and economic development but also natural environment conservation, no
single organization can achieve sufficiently the aspirations of sustainable rural development. Collaboration
among international, governmental and non-governmental organizations, together with the academe andscientific sector, is indispensable.
The knowledge and intelligence accumulated in universities and research institutions are also expected
to make the programs facilitated by the international, governmental and non-governmental organizations
more adequately implemented and meaningful to societal development. However, these cases especiallythose implemented locally have been scattered without having been summarized well or recorded in annals
academic or scientific societies.
So, the International Society of Environmental and Rural Development founded in 2010, aims to discussand develop suitable and effective processes or strategies on sustainable rural development focusing on
agricultural and environmental aspects in developing countries. The ultimate goals of the society are tocontribute to sustainable rural development through social and economic development in harmony with thenatural environment, and to support the potential or capacity building of local institutions and stakeholders in
the rural area with academic background.
Purposes of ISERD:
The primary purposes of ISERD are to contribute to sustainable rural development through social andeconomic development in harmony with the natural environment and to support the potential or capacity
building of local institutions and stakeholders in the rural area with academic background.
In order to enhance the realization of the primary purposes of ISERD, the secondary purposes are;- to facilitate interaction among international, governmental, non-governmental organizations and local
communities,- to hold conferences or symposia on environmental and rural development,- to edit the International Journal of Environmental and Rural Development,- to confer some awards based on scientific achievement, research paper or poster presentation, and- to encourage and develop local awareness concerning sustainable rural development.
Membership:
There shall be two categories of membership.
(a) Individual(b) Organizational
An application for membership of ISERD shall be submitted to the secretariat of ISERD, where is located in
the Research Center at Institute of Environmental Rehabilitation and Conservation (Japan) by writing or byother appropriate means.
Also every presenter who attends the International Conference on Environmental and Rural
Development (ICERD) is registered as an Individual Member of ISERD.

IJERD – International Journal of Environmental and Rural Development

Council of ISERD:
The affairs of ISERD shall be governed and managed by the ISERD Council. The councilors are as follows.
President
Prof. Dr. Mario T. Tabucanon, United Nations University, Institute for the Advanced Study of
Sustainability, Japan
Deputy Presidents
Prof. Dr. Bunthan Ngo, Royal University of Agriculture, Cambodia
Prof. Dr. Anan Polthanee, Khon Kaen University, Thailand
Prof. Dr. Eiji Yamaji, The University of Tokyo, Japan
Executive Secretary / Editor-in-Chief of IJERD
Prof. Dr. Machito Mihara, Tokyo University of Agriculture, Japan /Institute of Environmental Rehabilitation and Conservation, Japan
Managing Editors
Dr. Jeeranuch Sakkhamduang, Institute of Environmental Rehabilitation and Conservation /Association of Environmental and Rural Development, Thailand
Dr. Junaid Alam Memon, Pakistan Institute of Development Economics, Pakistan
Dr. Shinobu Terauchi, Institute of Environmental Rehabilitation and Conservation, Japan
Dr. Toru Nakajima, Tokyo University of Agriculture, Japan
Treasurer
Dr. Lalita Siriwattananon, Rajamangala University of Technology Thanyaburi, Thailand
Regional Vice Presidents
Dr. Abdul Malik Dawlatzai, Ministry of Agriculture, Irrigation and Livestock, Afghanistan
Prof. Dr. Barry N. Noller, The University of Queensland, Australia
Prof. Dr. Sinisa Berjan, University of East Sarajevo, Bosnia and Herzegovina
Dr. Buntong Borarin, Royal University of Agriculture, Cambodia
Prof. Dr. Dieter Trautz, University of Applied Sciences, Germany
Dr. Sri Wahyuni, Islamic University of Riau, Indonesia
Prof. Dr. Hiromu Okazawa, Tokyo University of Agriculture, Japan
Prof. Dr. Myo Kywe, Yezin Agricultural University, Myanmar
Dr. Junaid Alam Memon, Pakistan Institute of Development Economics, Pakistan
Prof. Dr. Regucivilla A. Pobar, Bohol Island State University, Philippines
Dr. Chuleemas Boonthai Iwai, Khon Kaen University, Thailand
Prof. Dr. Murari Suvedi, Michigan State University, USA
Dr. Nguyen Khoi Nghia, Cantho University, Vietnam
ISERD Secretariat:
Research Center, Institute of Environmental Rehabilitation and Conservation (ERECON)
2987-1 Onoji Machida-Shi, Tokyo 195-0064, Japan
Tel/Fax: +81-42736-8972
E-mail: iserd.secretariat@gmail.com
Webpage: www.iserd.net
Collaborated with

Association of Environmental and Rural Development (AERD)
93/64 Moo.3, Sinsab Village 2, Bungyeetho Sub-district, Thanyaburi District,Pathum Thani 12130, Thailand
Tel/Fax: +66-2957-8064
E-mail: iserd.secretariat@gmail.com
Webpage: www.iserd.net

Institute for the Advanced Studyof Sustainability
All articles and reports published in this journal were accepted through a peer-review process. However,most articles and reports published in this journal were presented at the International Conference on
Environmental and Rural Development that was co-organized by United Nations University, Institute for
the Advanced Study of Sustainability.

IJERD – Environmental and Rural Development

Vol. 10 No. 2

December 2019