Handbook on the methodology for an integrated experiment-survey on rice yield constraints

The methodology, the result of a 4-year multidisciplinary research project to study rice yield constraints by a team of agronomists, economists, and statisticians from the International Rice Research Institute (IRRI) and by 6 cooperating national teams, will give researchers answers to the following questions: (1) What is the gap between farmers" present yields and the highest potential yield for their fields after predetermined production factors are modified? (2) How much of the yield gap can be attributed to each of the predetermined production factors? (3) What are the differences in costs and returns? (4) How much of the yield gap can be profitably recovered? and (5) If the inputs that are most profitable differ from the actual inputs used by farmers, what personal, social, institutional, or political factors keep farmers from using the most profitable levels? The handbook discusses the selection of study area experimental sites, and factors to be tested (such as fertilizer, weed control, and insect control). Sample survey questionaires are presented and illustrative analyses are performed on constraint data.