Because several of Cambodia’s agricultural areas have degraded soils, the country is pursuing a sustainable agriculture approach aimed at growing food in a way that not only conserves the soil but also improves its quality. Working in partnership with U.S., French, and Brazilian researchers, local Cambodian scientists developed working technologies that enhanced soil quality and intensified production of upland grain, tuber, vegetable, forage, and lowland rice crops under conservation agriculture. The goal of the PEER-supported research project was to evaluate the capacity of the Soil and Water Assessment Tool (SWAT) to predict soil carbon sequestration in conservation agriculture production systems compared with traditional farming systems. Moreover, the project aimed at establishing a GIS-based weather, soil, land use, and agricultural management database that was housed in a central location for use as a baseline to help global users predict environmental degradation from current practices. SWAT was used as a reliable model for such simulations and to assess the environmental and economic benefits for Cambodia if sustainable intensification practices like conservation agriculture were promoted by the government and private industry. SWAT was based on the science behind the hydrologic cycle, nutrient cycle, carbon cycle, pesticide chemical degradation and movement, soil erosion processes, and crop growth and yield, combined as an integrated process. With support provided by PEER, Cambodian researchers collaborated with their U.S. partner to gather and format the inputs for SWAT simulation, including digital elevation maps and data on climate, soils, land use, crops, agricultural management, and types of fertilizers used. The results of the simulations were compared with measured data (where available) to assess the reasonableness of the simulations. Moreover, the U.S. partner provided technical expertise needed to accomplish critical objectives of the research project, as well as access to some equipment and laboratory instruments for analyses of water, soil, and plant samples.

 

It was expected that the project could improve agricultural management practices in Cambodia, as well as provide synthesized data that could be useful globally. Capacity building for faculty members of the Royal University of Agriculture was improved through the training and implementation activities involved in the project. From the GIS-based digital data collected in this proposal, research could be conducted with quantified data using SWAT to analyze the impact of deforestation and agriculture on the Mekong River natural flows. In addition, different types of sustainable intensification production systems could be recommended from various scenarios, and environmental conservation could be simulated using SWAT. Predictions could be linked to food production, improved yield and income, and the capacity of the community to meet its food needs.