The impact of alternative wetting and drying technique adoption on technical efficiency: empirical evidence from rice production in Mekong river delta, Vietnam

Abstract

One of the most serious issues that potentially lead to total rice yield losses is climate change and its consequence, water scarcity. To counteract with this problem, the International Rice Research Institute has developed and promoted the alternate wetting and drying (AWD) water saving technique among rice growing countries to save irrigation water as well as enhance productive cropping. However, after widely adopted, farmers have adjusted the technique differently in term of irrigating schedule and practice. These realities lead to a problem in measuring the degree of AWD technique adoption at farm level and investigating its impact on rice production. From the original AWD score, this study suggests a modified AWD score including water drainage practice to represent for the adoption degree of each farm, based on that AWD application impact on the rice production technical efficiency is also evaluated. Using the sample of 250 farms surveyed in Mekong River Delta provinces, the adjusted AWD score is calculated for each farm. Subsequently, a Stochastic Frontiers Cobb-Douglas production function is regressed using maximum log likelihood method to measure the technical inefficiency, after which, a function of technical inefficiency determinants is investigated, where AWD score was included as a main factor. Results indicate that higher AWD application degree can improve technical efficiency of the production. Thus, AWD technique should be continually promoted on large scale adoption and strictly followed IRRI instructions to improve rice production technical efficiency.