IJERD – International Journal of Environmental and Rural Development (2022) 13-1

Research article
erd

Farmers’ Organic and Inorganic Fertilizers Application andits Effects on Rice Productivity in Prey Chhor District,Kampong Cham Province
MUY LEANG KIM
Graduate School of Agriculture, Tokyo University of Agriculture, Japan
Email: muyleangkim70@gmail.com

MACHITO MIHARA*
Faculty of Regional Environment Science, Tokyo University of Agriculture, Japan /Institute of Environmental Rehabilitation and Conservation, Tokyo, Japan
Email: m-mihara@nodai.ac.jp
Received 7 July 2021

Accepted 18 October 2021(*Corresponding Author)

Abstract Kampong Cham Province is located in plain region of Cambodia. The major
activity of people in the province is agriculture, mainly cultivating rice and vegetables.
More than 60% of farmers in Kampong Cham Province applied chemical fertilizers
inappropriately without understanding on its impacts. The use of high rates of chemicalfertilizers continuously for several years, often lead to unsustainability in production andpost harmful to the environment. Recent years, with the support from the government andnon-governmental organization (NGOs), many farmers realized and look for a betteragricultural practice which could harmonize with natural environment and human health.
Several practices were carried to promote the use of organic fertilizers such as green
manures, compost, and bio-liquid fertilizer in Kampong Cham Province. The use of organic
fertilizers it can reduce the input of chemical fertilizer, improve soil, water, andenvironment quality. Therefore, the objectives of this study are to describe farmers’
practices on fertilization and discuss the effect of fertilization practices on productivity inSamraong and Baray Communes. Ones hundred farmers were selected for interview withquestionnaire surveys on agricultural practices in Samraong and Baray Communes. The
results from the questionnaire surveys showed that more than 70% to 80% of farmers inSamroang and Baray Communes applied organic in combination with inorgnaic fertilizers
and less than 20% use only inorganic fertilizers and 10% only organic fertilizer. The
amount of rice production in each fertilization practices was different, the rice production inorganic fertilizer practices was high compared to other fertilization practices in Baray
Commune, however, in Samraong Commune the rice production was high in chemicalfertilization practices. As farmers in Samraong Commune used more chemical that is why
the production was high compared to other fertilization practices.
Keywords organic farming, inorganic fertilizers, compost, sustainable agriculture,
Kampong Cham

INTRODUCTION
Plant nutrients are essential for the growth and productivity of crops. Farmers supply nutrients inthe form of organic and inorganic fertilizers. Recently, farmers in Asia have increased the use of
inorganic fertilizers over organic fertilizers, however, integration of both organic and inorganic
fertilizers helps to increase crop productivity, soil fertility and decreases the damage that can be
introduced by inorganic fertilizers. Moreover, farmers in Kampong Cham Province still lakeknowledge regarding the advantages and disadvantages of applying organic and inorganic
fertilizers.
Kampong Cham Province is located on the plain region of Cambodia. The province consistsof 9 districts and 1 municipality, 109 communes and 916 villages. The total population of thisⒸ ISERD

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province is about 1.6 million people in 2013 (JICA, 2013), which accounts for 12.5% of the total
population of Cambodia. The population is comprised of 80% farmers, 1% craftsmen, 14% service
providers and 5% engaged in other businesses. Agriculture activities of people in Kampong Cham
Province are changing from subsistence to commercial monoculture with increased use ofinorganic fertilizers.
Organic and inorganic fertilizers are important for achieving an increase in crop productivity(Tong, 2010), if there is enough supply of nutrients to the soils, crop will grow well and produce
high yields. Application of organic fertilizers, compared to inorganic fertilizers, maintain soilquality by increasing soil organic matter as well as improve soil physical and chemical properties
through decomposition of its substances (Mader et al., 2002). Additionally, Farmers in Baray
Commune, Prey Chhor District of Kampong Cham Province has been applied organic fertilizers formore than 10 year which results in better soil properties with organic fertilizer application.
Compared to that in Samraong Commune, farmers applied organic fertilizer for only 5 years inresults there was not clearly shown the influence of organic fertilizer application on soil properties(Kim and Mihara, 2018). Therefore, the study focused on investigating farmers fertilization
practices and the effect of fertilization practices on n productivity in Samraong and Baray
Communes, Prey Chhor District, Kampong Cham Province.
OBJECTIVE
The objectives of this study are to investigate and describe farmers’ fertilization practices and todiscuss the effect of different fertilization practices on rice productivity in Samraong and Baray
Communes.
METHODOLOGY
Study Site
The study is focused in Samraong and Baray Communes in Prey Chhor District, Kampong ChamProvince (Fig.1).
Cambodia

Prey Chhor District
Kampong Cham Province
BaraySamraong

Fig. 1 Maps of the study areas and location of Samraong and Baray Communes, Prey ChhorDistrict, Kampong Cham Province
Samraong Commune consists of 11 villages and 1,714 households, the farmers in this commune
own cultivation land less than 1 ha. The main crops produced are rice and vegetables with main soil
types being brown hydromorphics, regurs and cultural hydromorphics. The number of farmers thatapplied chemical fertilizer or inorganic fertilizers were 1,587 out of 8,123 peoples.
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Baray Commune consists of 13 villages, 2,446 households, with average cultivation land lessthan 1 ha. The main crops cultivated are rice and vegetables. The soil types are the same in bothcommunes, In Bary Commune, 1,479 farmers out of 10,637 people used chemical fertilizer (CDB,2010).
Data Collection and Analysis
Secondary data collection: Relevant documents were collected from the research institutions
journals and reports of the project implement and the experts who had studied in the study areas.
Primary data collection: Ones hundred farmers were selected randomly for interview inSamraong and Baray Communes. The contents of the interview and questionnaire surveys mainly
focused on the general information of farmers, and agricultural condition, especially on soil fertilitymanagement.

Fig. 2 Conducting questionnaire survey
Data analysis: To describe farmers fertilization practices and amount of fertilizer applied, total
nitrogen was used for calculating the amounts of fertilizers used in the study areas. Based oninterview and questionnaire surveys the total amounts of nitrogen applied in each fertilizer wascalculated with equation (1). Based on total amount of nitrogen applied, the degree of organic andinorganic fertilizers dependency was calculated with Equations (2) and (3).
Total N (kg/ha/yr)(1)

Organic Fertilizer Dependence (OFD%)

× 100

Inorganic Fertilize Dependence (IFD%) = 100 – OFD%

(2)
(3)

RESULTS AND DISCUSSION
Types of Fertilizers Uses among Responded Farmers
Based on the interview and questionnaire survey on fertilizers practices of farmers in Samraongand Baray Communes showed that farmers applied Urea and Diammonium phosphate (DAP) as
inorganic fertilizers and manures and composts as organic fertilizer. The Urea, DAP and manure orcompost fertilizer all contained nitrogen content. The commercial rate of nitrogen content in Urea
is 46% and DAP is 18%. However, Kim and Mihara in 2018 analyzed the nitrogen content in Urea,
DAP and manure used by farmers in Samraong and Baray Communes showed that the nitrogen in
inorganic fertilizers were low compared to the commercial rates (Table 1).
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Table 1 Common types of fertilizers applied and the nitrogen content of fertilizers
Name

Chemical formulaeN%

N% *Urea
Diammonium phosphate (DAP)
Manure or compostCO(NH2)246
18

43.37
15.43
0.36(NH4)2 HPO4

* Nitrogen content by Kim and Mihara, 2018

Fig. 3 Chemical fertilizer (left) and compost manure (right)

A*

B*

A*
A* A*
B*

Fig. 4 Amounts of fertilizer applied in
Samraong and Baray Communes

Fig. 5 Amounts of nitrogen applied inSamraong and Baray Communes

Farmers in Samraong and Baray Communes applied Urea in average is 424 kg/ha/yr and 117
kg/ha/yr, DAP is 320 kg/ha/yr and 63 kg/year/ha, and manure is 8,768 kg/ha/yr and 8,968 kg/ha/yr,
respectively (Fig. 4). The amounts of fertilizers used in each fertilization were converted to theamounts of nitrogen contents (Fig. 5). As the results showed fertilizers applied in both Samraong
and Baray Commune were significantly different in 95%, especially in inorganic fertilization
practices. Farmers in Samraong Commune applied higher inorganic fertilizers than farmer in BarayCommune.
Farmers’ Fertilization Practices
Farmers in Samraong and Baray Communes practiced organic, chemical, and organic incombination with chemical fertilizers. There were 4%, 12% and 84% of farmer household who
applied organic, inorganic, and combine in Samraong Commune, respectively. 8%, 16% and 76%
of farmer applied only organic, inorganic, and combine in Baray Commune, respectively (Fig. 6).
As the result, both communes are likely combining organic and inorganic fertilizers for agriculturalproduction.

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Fig. 6 Comparison between farmer households who applied different fertilizers inSamraong (left) and Baray Communes (right)
The amounts of nitrogen used in Samraong and Baray Communes in each fertilization
practices were different. In Samraong Commune, nitrogen usage was high in inorganic fertilization
practices and combine compared to organic fertilization practices. However, in Baray Commune
the amounts of nitrogen use in organic, inorganic, and combine were not different. As comparing
the nitrogen use in both communes showed that farmers in Samraong Commune applied more
nitrogen in inorganic fertilizers and combine of organic and inorganic fertilization practices.

A*A*

Different letters
indicate * p<0.05

A*AA

B*

B*

Fig. 7 Average amounts of nitrogen applied in each fertilization practices (kg/ha/yr)
in Samraong and Baray Communes

Different letters
indicate * p<0.05

Fig. 8 Amounts of rice production (kg/ha/yr) in Samraong and Baray Communes

Effect of Different Fertilizer Practices on Rice ProductivityⒸ ISERD

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The amounts of rice production were significantly different at 95% interval in each fertilization
practices in Samraong and Baray Communes. Comparing rice production between Samraong andBaray Communes showed that the rice production shown higher in organic and combine of organicand inorganic fertilizer practices in Baray Commune (Fig. 8). Also, the rice production was notdifferent in inorganic fertilization practices in both communes. It was considered that organic
fertilizer application helps to increase the rice productivity in Baray Commune. As farmers in
Baray Commune applied less chemical and more organic fertilizer for long term, when organic
fertilizer has been applied for long time, the production was high indicating on good soil quality.

Fig. 9 Amounts of rice production (kg/ha/yr) in Samraong (left) and Baray Communes (right)

There was positive ration between organic fertilizer dependence (OFD%) and rice yields per
nitrogen applied at 95% confidence interval in Baray Commune. The combine of organic fertilizer
from 50% to 60% with inorganic fertilizers showing good results to increase the productivity in
Baray Communes (Fig. 9). However, in Samraong Commune the good rate of organic fertilizer incombination with inorganic fertilizer was from 30% to 40%. As the results the combined
application of organic fertilizers such manures or compost and inorganic fertilizer enhanced tiller
number, panicle length and yield attribute of rice compared to only inorganic fertilizers application(Kakar et al., 2020).
CONCLUSION
Farmers in Samraong and Baray Communes combined organic and inorganic fertilizers, there arealso a few farmers who applied only organic or only inorganic fertilizers. The main sources ofnitrogen for farmers in Samraong Commune are likely from inorganic fertilizer, while in Baray
Commune the sources of nitrogen both from organic and inorganic fertilizers. The use of nitrogenin Samraong Commune in inorganic fertilization practice and combine was higher, while the riceproduction was lower compared to Baray Commune. Farmer in Samraong applied more inorganic
fertilizer, but the rice production was not different compared to Baray Commune when farmers
applied fewer inorganic fertilizers. Organic fertilizer application helps to increase in riceproductivity in Baray Commune, as farmers in Baray has been applied organic fertilizer for morethan 10 years and less inorganic fertilizers. It was considered that when organic fertilizer has been
applied for many years like Baray Commune, the production was high in organic fertilization andcombined. Inconclusion of more organic fertilizer and less inorganic is strongly recommended tofarmers in Samraong and Baray as organic fertilizer contributed to increase the rice productivity.
REFERENCE
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Kakar, K., Xuan, D.T., Noori, Z., Aryan, S. and Gulab, G. 2020. Effects of organic and inorganic fertilizer
application on growth, yield, and grain quality of rice. Agriculture, 10 (11), 544.
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Mäder, P., Fliessbach, A., Dubois, D., Gunst, L., Fried, M.P. and Niggli, U. 2002. Soil fertility andbiodiversity in organic farming. Science, 296, 1694-1697.
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