A system to reduce risk in the adoption of new rice production technologies in Cambodia

• Ministry of Agriculture, Cambodia
• CSIRO Land and Water, Australia

For many years Australia has funded the International Rice Research Institute (IRRI) to lead an extensive project in Cambodia, where the government is striving to increase rice yields through the introduction of modern production techniques. This small project was associated with this work, and its purpose was to develop systems that would increase the efficiency of crop and soil management in lowland rainfed rice cropping environments of Cambodia.

The scientists aimed to develop a model that integrated knowledge emanating from research in different disciplines, in order to optimise management of nutrients and fertilisers, farming systems and crop pests and to obtain greater understanding of socioeconomic issues and agricultural engineering practices.

The scientists developed a comprehensive, integrated economic database from experimental records held by the Cambodian IRRI-Australia Project (CIAP), the Cambodian Agronomy Department, provincial agricultural offices and NGOs. They used the data to estimate yield probability distributions for different soil types and soil fertility levels, and to forecast seasonal weather conditions. These estimates were then fed into the model. The scientists also incorporated knowledge from farmers and other experts from Cambodia and the surrounding region into the model.

The scientists compiled a data set for Takeo province, where a large number of field experiments had been conducted since 1992. The data set was used to generate provincial-scale maps of crop yield and response to fertilizer. Maps showing crop response to applications of nitrogen, phosphorus or potassium fertilizer were generated for the province. The data revealed a strong positive response to nitrogen application, particularly in the central-western region of the province, but there was a possible negative effect on the rich soils in the flood-prone areas of the southeast, probably due to increased damage from stem borers. Further on-farm experiments were recommended to confirm that nitrogen fertilizer application increases stem borer damage.
Fifty farmers from each of three villages were interviewed to gather knowledge about fertilizer use, and also the effects fertilizer application, drought and flooding on yield in their rice crops. Interviewers also gathered information about the physical, economic and social environment. The survey revealed that farmers in Takeo province were clear about what they were doing and why. At times this deviated from what the researchers thought they should be doing, and the researchers concluded that novel approaches were necessary to combine research findings with farmer knowledge, in other words a cooperative approach would be needed to attain best practice in nutrient management.
At the provincial scale maps pinpointed areas where greater extension effort would be most effective and areas where current research is inadequate. This knowledge should ensure greater strategic planning capability to deliver extension services and encourage better use of fertilizers. In return the researchers should learn by observation much about how they can help localities that do not receive the full benefit of using fertilizers.
A striking outcome of the project was the combining of four data sets of on-farm trials to produce meaningful outputs. It illustrated the value of collaborating with other agencies to access already-existing data before undertaking independent data gathering. This activity has added value to on-farm research for all four agencies involved and should accelerate the adoption of research findings. As many of Cambodia's soils are very infertile, there are immediate benefits possible from better fertilizer and nutrient management.