An environmental economics analysis of a rice-duck ecological management technique with no-tillage
免耕稻-鸭生态种养技术的环境经济学分析

This study is aimed at the ecological and economical benefits of the rice-duck ecological management technique with no-tillage through the adoption of field experiment and environmental economic approaches. The results showed that the farmers' control over field weeds was remarkably effective with the application of this technique. In the initial tillering stage and the full tillering stage of late rice, the rice-duck ecological management technique with no-tillage was 100% effective in the prevention of Chilo suppressalis. The incidence rate of Cnephalocrocis medinalis was 48.05% and 93.55% lower, respectively, than that of the no-tillage cast-transplant area without duck. As for the diseased plant ratios of sheath blight in the no-tillage cast-transplant area with duck it showed 48.15% and 38.21% lower, respectively, than that of the no-tillage cast-transplant area without duck. The control of methane emission was apparently effective in the no-tillage cast-transplanted area with duck over the peak period (in the initial tillering stage and the full tillering stage of late rice), when compared with the conventional-tillage cast-transplant area without duck, showing a reduction of 4.723g/m~2. In comparison with the no-tillage cast-transplant area without duck, the amount of methane emission was reduced 2.333g/m~2. For the total course of late rice, the amount of methane emission in the no-tillage cast-transplant area with duck was reduced 3.37g/m~2 compared with that of the no-tillage cast-transplant area without duck, and reduced 5.59g/m~2 in comparison with that of the conventional-tillage cast-transplant area without duck. No-tillage could save 1300m~3/hm~2 of irrigation water. Analysis of environmental economics indicated: compared with the farmers who adopted the no-tillage cast-transplant without duck technique and those who adopted the conventional-tillage cast-transplant without duck technique,the farmers adopting the rice-duck ecological management technique with no-tillage showed a possible income increase of 2166yuan/hm~2 and 4207yuan/hm~2, respectively. The economic net benefit of the no-tillage cast-transplant with duck technique was 4062yuan/hm~2, and those using the no-tillage cast-transplant without duck technique and the conventional-tillage cast-transplant without duck technique respectively earned 1592yuan/hm~2 and -997yuan/hm~2. The rice-duck ecological management technique with no-tillage might not only bring about the ecological and economic benefits for a compound ecological system with rice-duck, but also may overcome the disadvantages that the no-tillage brings to the ecological environment, thus making it a sustainable agricultural production mode with a potential of promotion and development.