IJERD – International Journal of Environmental and Rural Development (2023) 14-1

Research article
erd

The Effects of Green Manure on Sustainable Agriculture Soil
Conservation under Open Field Conditions
MALA SUON*
Department of Food Processing, Faculty of Agriculture and Food Processing,
National Meanchey University, Sisophon, Cambodia
Email: suon.mala.mcu@moeys.gov.kh

SOPHEAK TITH*
Faculty of Agriculture and Food Processing,
National Meanchey University, Sisophon, Cambodia
Email: tethsopheak@gmail.com

THANGRAK VEU
Department of Veterinary, Faculty of Agriculture and Food Processing,
National Meanchey University, Sisophon, Cambodia

PISIDH VOEFaculty of Agriculture and Food Processing,
National Meanchey University, Sisophon, Cambodia

SOCHEAT NGY
Faculty of Agriculture and Food Processing,
National Meanchey University, Sisophon, Cambodia

SOTHEA HILL
Faculty of Agriculture and Food Processing,
National Meanchey University, Sisophon, Cambodia

CHHOUK CHHEANG
Faculty of Agriculture and Food Processing,
National Meanchey University, Sisophon Cambodia
Received 16 January 2023

Accepted 10 June 2023(*Corresponding Author)

Abstract Green manure is a type of crop that is used for soil enhancement, both physical andbiological. It is enriched with organic matter that provides nutrients to the soil and improves
soil fertility. However, improper chemical use by farmers results in soil degradation andadverse effects on beneficial soil microorganisms. To mitigate this problem, farmers need touse fertilizer only as required. The purpose of the current study was to grasp the efficacy ofgreen manure on soil improvement, with consideration of the principles of sustainableagriculture. The research aimed to study the effect of green manure on soil properties
including soil pH, soil EC, and available nitrogen. Experiments were carried out in field
conditions at the National Meanchey University, Cambodia, from June 25 to July 25, 2022.
The experiment was laid out in a randomized complete block design (CRBD) with 4
treatments and 8 replications utilizing green manure produced from different plants. Treatment
T0 represented the control, T1 Glycine max, T2 Vigna radiata, and T3 Crotalaria Juncea.
The result showed that green manure has a significantly positive effect on soil properties
such as pH, electric conductivity, and available nitrogen. T3 produced the highest posttreatment soil pH and reduction in soil electric conductivity (EC), which averaged 7.14 and0.46, respectively. T2 provided the greatest amount of available nitrogen, while untreated soil
was not significantly different among treatments. Therefore, the application of green manure
can be a vital choice in soil improvement for sustainable agriculture and increased yield.

Ⓒ ISERD

147

IJERD – International Journal of Environmental and Rural Development (2023) 14-1

Keywords green manure, fertilizer, soil, sustainable agriculture

INTRODUCTION
Soil health is defined as the capacity of the soil to function as a living system, with ecosystem andland use boundaries. It sustains plant and animal productivity, maintains or enhances water andair quality, and promotes plant and animal health. It is based on the interaction, balance, and stabilityof the physical, chemical, and biological properties of soil, which have direct effects on nutrient
cycling, soil structure, water availability, and pests and diseases, ultimately affecting crop healthand yield (Patil and Solanki, 2016).
Consequently, fertilization increases efficiency and obtains better quality product recovery inagricultural activities. Fertilizer use has increased by 70%, and pesticide use has increased severalfold (Savci, 2012; Tilman et al., 2002). As a result, fertilization causes the accumulation of heavy
metals in soil and plant systems. Long-term unbalanced use of agrochemicals may lead to acommunity shift of beneficial microorganisms with dangerous consequences for soil physical andchemical structure (Hamidov et al., 2007). Soil structure in agricultural productivity is very
important and it is regarded as an indicator. Unconsciously, the fertilizing of soil, just as in thedeterioration of the structure is caused by industrial emissions. Especially NaNO3, NH4NO3,KCI, K2SO4, and NH4Cl demolish the structure, such as fertilizers, soil, and soil structure, anddeterioration is difficult to obtain high-quality and efficient products (Shaviv, 2001). Moreover, soil
degradation has strong negative economic impacts since a large part of the population relies on
agriculture as a primary source of income (Lal, 2015). More than 500 million hectares of tropicalarable land and 33% of the earth's land surface globally face a decline in soil health (Lamb et al.,2005).
Therefore, green manure is considerable for use in soil improvement in terms of sustainableagriculture because it provides numerous benefits to crop production and soil health (Magdoff, 2001).
According to Pandey et al., (2008), green manuring helped advance the soil's physical andbiochemical anatomy, prevented leaching losses of nutrients, and added water-holding capacity.
The approved use of green manuring resulted in high organic matter reserves which added bothsoil physical and chemical properties if compared to controlled fields. This is because they can help
conserve, maintain, or replenish soil resources, including organic matter, nitrogen and othernutrient inputs, and physical and chemical properties (Sarrantonio and Gallandt, 2003). Several
studies have investigated cereal-legume intercropping. Legumes are found in natural ecosystems
and are key to promoting ecosystem efficiency such as nitrogen fixation, soil microbial health,and ecological network of biodiversity of soil (Duchene et al., 2017; Zhang et al., 2021). Likewise,Ablimit et al. (2022) revealed that microbial phylotypes were grouped into four major ecologicalclusters. The application of green manure led to significantly increased soil pH, nutrient contents,and enzyme activities, and significantly reduced the relative abundance of potential plant
pathogens compared with monocropping, which should ensure high and stable maize yield underlong-term continuous cropping (Charron and Sams, 1999).
We conduct research based on sustainable agriculture in an effort to achieve Cambodia’s action
plan of Zero Growth on Chemical Fertilizers by 2050. The outcome of the research will be sharedwith farmers in an effort to maintain the environment and increase food safety.
OBJECTIVE
The research aims to enhance the soil property by inoculation of green manure from different
plants, (i) Glycine max, (ii) Vigna radiata, and (iii) Crotalaria Juncea, in an open field at theNational Meanchey University, Cambodia.
METHODOLOGYⒸ ISERD

148

IJERD – International Journal of Environmental and Rural Development (2023) 14-1

Experimental Design and Plantation
This research was carried out at National Meanchey University from June 25, 2022, to July 25, 2022.
The experiment was carried out by randomized complete block design (RCBD) consisting of four
treatments and three replications (Table 1). Each block had a 2 m x 2 m diameter and a length of 0.5
m for a total area of 66.5 m2. For the plantation, each plant was planted in the experimental field
by using different types of plants for comparison. Green manures were plowed into the soil to a depthof 10 cm length after one month of plantation. Each treatment was plowed two times per day afterfermentation. Treatment zero was the control, treatment one (T1) used Glycine max, treatment two(T2) used Vigna radiata, and treatment three (T3) used Crotalaria Juncea.
Table 1 Treatment and composition
Treatment
Control
Treatment 1
Treatment 2
Treatment 3

Inoculation
Uninoculated
Glycine max
Vigna radiata
Crotalaria Juncea

Reference: Blomme et al. (2022)

Soil Chemical Analysis
Soil samples were collected before and after plantation in the field experiment of the National
Meanchey University. Upon collection, soil samples were sent immediately to the soil laboratory
for further analysis including soil pH, soil electrical conductivity (EC), and available nitrogen, which
followed the method of Kjeldahl (Cunniff, 1995). Soil pH was determined using the method of Kumaret al. (2014), while EC was analyzed according to the method proposed by Kargas et al. (2022).
Data Analysis
Data were analyzed for analysis of variants (ANOVA) using the R program version (4.0.3). The
differences among means were tested by Duncan’s multiple range tests at p ≤ 0.05.
RESULTS AND DISCUSSION
Before planting, soil pH was detected to be the same value for all treatments. This was due to soil
experimentation being in the same condition. However, the effect of intercropping on soil pH result
displayed that application of green manure enhances soil pH significantly, increasing amongtreatments ( Fig. 1) As a result, treatment 3 (T3) and treatment 4 (T4) provided the highest soil pH
values, which ranged from 6 to 7. Our research strongly agreed with Kawu (2020), and found thatincorporating green manure crops significantly influenced soil pH at harvest. This phenome isdue to a major contribution of soil decomposition by microbial activity when incorporated into thesoil (Msimbira and Smith, 2020). Previous studies have reported higher soil organic matter, nitrogen,phosphorus, potassium, calcium, and magnesium contents due to incorporating green manure (Biswasand Mukherjee, 2001; Herrera et al., 2007).
Soil reduction regarding electrical conductivity was examined and was found without significant
difference relative to the control, which ranging from 1.20 to 1.44 dSm-1. However, soil EC was foundsignificantly reduced after incorporating green manure into the soil among different treatments (Fig.
2). Moreover, treatment three (T3) resulted in the greatest reduction in soil EC, with a value of 0.49
dSm-1. Similar results, indicating that green manure reduced soil EC, were obtained by Bhayal et al.
(2018). This decrease was due to the addition of readily decomposable organic matter in the form ofgreen manure with accumulation of the CO2 either may be due to the precipitation of Fe2+, Mn2+ andconsequent adsorption of other cations on the exchange site and decomposition of organic acid (Harishand Devasenapathy, 2010).
Ⓒ ISERD

149

IJERD – International Journal of Environmental and Rural Development (2023) 14-1

Fig. 1 The effect of green manure on soil pH before and after plantation

Fig. 2 The effect of green manure on soil electric conductivity
Green manure is usually considered as a cover crop sown to enhance the fertility of the soil
between two crops demanding high nitrogen inputs (Sanaullah et al., 2022). After incorporation
in soil, the result displayed that green manure had significantly increased the available nitrogen(P < 0.05). Barradas et al. (2001), in an experiment with eight species of green manure, observedthat white lupine and common vetch were the species that accumulated the highest total N in
the whole plant, with amounts of 251.6 and 228.1 kg/ha, respectively. Our result agreed with thoseof Salahin et al. (2013), finding that green manure has significantly increased soil organic matter,soil health, and crop growth. Moreover, the author found that green manure increased SOM andTN which was obtained from V. radiata and S. aculeata. There may be a difference in time andspecies of plant in this result. On the other hand, after incorporation into the soil, the nutrients in theplant biomass were released during the process of decomposition (Piotrowska and Wilczewski,2012).

Fig. 3 The effect of green manure on soil available nitrogenⒸ ISERD150

IJERD – International Journal of Environmental and Rural Development (2023) 14-1

CONCLUSION
The incorporation of Glycine max, Vigna radiata, and Crotalaria Juncea as green manure showed
a positive response on soil pH, soil electrical conductivity, and available nitrogen . Therefore,
we concluded that treatments 1, 2, and 3 provided a positive result for soil health, but only treatment
2 provided the greatest value of available nitrogen.
ACKNOWLEDGEMENTS
I would like to express my profound gratitude to Mr. Sopheak TITH for his contribution as alaboratory technician at the Faculty of Agriculture and Food Processing, and the Dean of the Facultyof Agriculture and Food Processing for the contributions to the completion of my project titled"The effects of green manures on sustainable agriculture soil conservation under open field". We
would also like to acknowledge the National Meanchey University for supporting this research.
REFERENCES
Ablimit, R., Li, W., Zhang, J., Gao, H., Zhao, Y., Cheng, M. and Chen, Y. 2022. Altering microbial community
for improving soil properties and agricultural sustainability during a 10-year maize-green manureintercropping in northwest China. Journal of Environmental Management, 321, 115859, Retrieved fromDOI https://doi.org/10.1016/j.jenvman.2022.115859
Barradas, C.A., Freire, L.R., Almeida, D.B. and De-Polli, H.J. 2001. Behaviour of temperate green manurespecies in a mountain region of the Rio de Janeiro State, Brazil. Brazilian Journal of AgriculturalResearch, 36, 1461-1468, Retrieved from DOI https://doi.org/10.1590/S0100-204X2001001200003
Bhayal, D., Khaddar, V. K. Bhayal, L. Yadav, T. C. Bangar, K. S. and Singh, B. 2018. Effect of sunhemp green
manuring and intercropping on soil properties. International Journal of Current Microbiology and AppliedSciences, 7, 371-384.
Biswas, T.D. and Mukherjee, S. 2001. Textbook of soil sciences. (2nd Ed.), Tata McGraw-Hill Education, New
Delhi, India, ISBN 0074516795-9780074516799-314.
Blomme, G., Ntamwira, J. and Ocimati, W. 2022. Mucuna pruriens, Crotalaria juncea, and chickpea (Cicerarietinum) have the potential for improving the productivity of banana-based systems in the Eastern
Democratic Republic of Congo. Journal of Legume Science, 4 (4), 145, Retrieved from DOI https://doi.
org/10.1002/leg3.145
Charron, C. S., and Sams, C. E. 1999. Inhibition of Pythium ultimum and Rhizoctonia solani by shredded leavesof Brassica species. Journal of the American Society for Horticultural Science, 124 (5), 462-467, Retrieved
from https://doi.org/10.21273/JASHS.124.5.462
Cunniff, P. 1995. Official Methods of Analysis of AOAC International. 16th edition, United States of America.
Duchene, O., Vian, J.F. and Celette, F. 2017. Intercropping with legume for agroecological cropping systems,
Complementarity and facilitation processes and the importance of soil microorganisms, A review.
Agriculture, Ecosystems and Environment, 240, 148-161, Retrieved from DOI https://doi.org/10.1016/j.
agee.2017.02.019
Hamidov, A.D., Khaydarova, N.A., Khamidov, M.U., Neves, A.L. and Beltrao, J.O. 2007. Remediation of saline
soils using Apocynum lancifolium and Chenopodium album. In Proceedings of the 3rd IASME/WSEAS Int.
Conf. on Energy, Environment, Ecosystems and Sustainable Development, Agios Nikolas, Greece,Retrieved from URL http://www.wseas.us/e-library/conferences/2007creteeeesd/papers/562-129.pdf
Harish, D., and Devasenapathy, P.S. 2010. Influence of green manure and different organic sources of nutrientson yield and soil chemical properties of rice (Oryza sativa L.) grown under lowland condition. International
Journal of Agricultural Sciences, 6 (2), 433-438.
Herrera-Arreola, G., Herrera, Y., Reyes-Reyes, B.G. and Dendooven, L. 2007. Mesquite (Prosopis juliflora(Sw.) DC.), huisache (Acacia farnesiana (L.) Willd.) and catclaw (Mimosa biuncifera Benth.) and their effecton dynamics of carbon and nitrogen in soils of the semi-arid highlands of Durango, Mexico. Journal of Arid
Environments, 69 (4), 583-598, Retrieved from DOI https://doi.org/10.1016/j.jaridenv.2006.11.014
Kargas, G., Londra, P., and Sotirakoglou, K.J.W. (2022). The effect of soil texture on the conversion factor of
1:5 soil/water extract electrical conductivity (EC1:5) to soil saturated paste extract electrical conductivity(ECe). Water, 14 (4), 642, Retrieved from https://doi.org/10.3390/w14040642
Kawu, A. (2020). Effect of some leguminous green manure crops and nitrogen levels on soil chemical propertiesof maize (Zea mays L.) grown soil. IAR Journal of Agriculture Research and Life Sciences, 1 (1), 17-25.
Ⓒ ISERD

151

IJERD – International Journal of Environmental and Rural Development (2023) 14-1

Kumar, V., Vimal, B. K., Kumar, R., and Kumar, M. 2014. Determination of soil pH by using digital image
processing technique. Journal of Applied and Natural Science, 6 (1), 14-18, Retrieved from https://doi.org/10.31018/jans.v6i1.368
Lal, R. 2015. Restoring soil quality to mitigate soil degradation. Sustainability 2015, 7 (5), 5875-5895, Retrieved
from DOI https://doi.org/10.3390/su7055875
Lamb, D., Erskine, P.D. and Parrotta, J.A. 2005. Restoration of degraded tropical forest landscapes. Science,
310 (5754), 1628-1632, Retrieved from DOI https://doi.org/10.1126/science.1111773
Magdoff, F. 2001. Concept, components, and strategies of soil health in agroecosystems. Journal of Nematology,
33 (4), 169, Retrieved from URL https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2620515/pdf/169.pdf
Msimbira, L.A. and Smith, D.L. 2020. The roles of plant growth-promoting microbes in enhancing plant
tolerance to acidity and alkalinity stresses. Frontiers in Sustainable Food Systems, 4, 106, Retrieved from
DOI https://doi.org/10.3389/fsufs.2020.00106
Pandey, D.K., Pandey, R., Mishra, R.P., Kumar, S. and Kumar, N. 2008. Collection of Dhaincha (Sesbania spp.)
variability in Uttar Pradesh, biodiversity, and agriculture (souvenir). Uttar Pradesh Biodiversity Board,Lucknow, 48-51.
Patil, H.J. and Solanki, M.K. 2016. Microbial inoculant, Modern era of fertilizers and pesticides. In Singh, D.,Singh, H. and Prabha, R. (Eds), Microbial Inoculants in Sustainable Agricultural Productivity, Springer, New
Delhi, India, Retrieved from DOI https://doi.org/10.1007/978-81-322-2647-5_19
Piotrowska, A. and Wilczewski, E. 2012. Effects of catch crops cultivated for green manure and mineral nitrogen
fertilization on soil enzyme activities and chemical properties, Geoderma, 189, 72-80, Retrieved from DOI
10.1016/j.geoderma.2012.04.018
Salahin, N. Alam, M.K., Islam, M.M., Naher, L. and Majid, N.M. 2013. Effects of green manure crops andtillage practice on maize and rice yields and soil properties. Australian Journal of Crop Science, 7 (12), 19011911, Retrieved from URL http://www.cropj.com/islam_7_12_2013_1901_1911.pdf
Sanaullah, M. Mujtaba, A. Haider, G. ur Rehman, H. and Mubeen, F. 2022. Mitigation and actions toward
nitrogen losses in Pakistan. In Aziz, T., Wakeel, A., Watto, M., Sanaullah, M., Maqsood, M. and Kiranm,A. (Eds.), Nitrogen Assessment, 149-175, Pakistan, Retrieved from DOI https://doi.org/10.1016/B978-0-12824417-3.00001-0
Sarrantonio, M. and Gallandt, E. 2003. The role of cover crops in North American cropping systems. Journal ofCrop Production, 8 (1-2), 53-74, Retrieved from DOI https://doi.org/10.1300/J144v08n01_04
Savci, S. 2012. Investigation of the effect of chemical fertilizers on the environment. APCBEE Procedia, 1, 287292, Retrieved from DOI https://doi.org/10.1016/j.apcbee.2012.03.047
Shaviv, A. 2001. Advances in controlled-release fertilizers. Advances in Agronomy, 71, 1-49, Retrieved fromDOI https://doi.org/10.1016/S0065-2113(01)71011-5
Tilman, D., Cassman, K.G., Matson, P.A., Naylor, R. and Polasky, S. 2002. Agricultural sustainability andintensive production practices. Nature, 418, 671-677, Retrieved from DOI https://doi.org/10.1038/nature01014
Zhang, N., Nunan, N., Hirsch, P.R., Sun, B., Zhou, J. and Liang, Y. 2021. Theory of microbial coexistence inpromoting soil–plant ecosystem health. Biology and Fertility of Soils, 57, 897-911, Retrieved from DOI
https://doi.org/10.1007/s00374-021-01586-wⒸ ISERD152