稻-鸭生态种养技术减排甲烷的研究及经济评价

【目的】稻－鸭生态种养技术是中国传统农业的精华，研究其减排CH4的效果，为进一步开发利用这一经典农艺提供理论基础和实践依据。【方法】采用田间试验及经济学方法研究稻-鸭生态种养技术减排CH4的效果及经济效益。【结果】稻田CH4排放通量的日变化与气温日变化基本一致。稻田CH4排放通量的高峰值出现在晚稻分蘖盛期，免耕养鸭稻田、免耕不养鸭稻田和翻耕不养鸭稻田的CH4排放通量分别为24.1、32.2和40.5 mg·m-2·h-1。在晚稻分蘖始-分蘖盛期，稻-鸭生态种养技术对稻田CH4排放的控制效果明显，分别比免耕不养鸭稻田、翻耕不养鸭稻田的CH4排放量减少2.333、4.723 g·m－2。晚稻整个生育期间，免耕养鸭稻田CH4排放量比免耕不养鸭稻田、翻耕不养鸭稻田分别减少3.373和5.590 g·m－2。采用免耕稻-鸭生态种养技术农户的财务净效益比采用免耕不养鸭技术和翻耕不养鸭技术农户分别增加2 166、4 207 yuan/ha。减去CH4排放的环境成本，采用稻－鸭生态种养技术的农户的经济效益为5 000 yuan/ha，比采用免耕不养鸭技术和翻耕不养鸭技术的农户分别增加2 206和4 274 yuan/ha。【结论】稻-鸭生态种养技术既能增加农户的财务收入，又能减少稻田CH4排放量，具有较好的环境效益，是一种很有发展潜力的可持续农业生产模式。

Studies on Technique of Reducing Methane-Emission in a Rice-Duck Ecological System and the Evaluation of Its Economic Significance

【Objective】The rice-duck ecological system is one of the cream practices from the traditional Chinese agriculture. Study on the effect of reducing methane-emission of this practice could provide theoretical and practical basis for further development and utilization of this classical agricultural technique.【Method】The effect of reducing methane-emission and the economic benefits of rice-duck ecological system were studied by adopting a field experiment and economic methodology. 【Result】The daily variation of CH4 emission in late rice paddy field was basically consistent with the daily variation of air temperature. The highest emission occurred at the full tillering stage of late rice with a rate of 24.1 or 32.2 or 40.5 mg·m-2·h-1 in no-tillage area with duck and no-tillage area without duck and conventional-tillage area without duck, respectively. The inhibition of methane-emission was apparently effective in the rice-duck ecological system during the initial tillering stage and the full tillering stage. Compared to the no-tillage area without duck, methane-emission decreased by 2.333 g·m-2. While compared to the conventional-tillage area without duck, methane-emission decreased by 4.723 g·m-2 growth. During the production period of late rice, the amount of methane-emission in no-tillage area with duck was 3.373 g·m-2 less than that of no-tillage area without duck, and 5.59 g·m-2 less than that of conventional-tillage without duck area. The economic significance was analysed. Farmers adopting the rice-duck ecological system obtained 2 166 and 4 207 yuan/ha more income than those who adopted a no-tillage without duck technique or conventional-tillage without duck technique, respectively. In addition to the reduction of the environmental pollution by methane emission, the farmers who adopted the rice-duck ecological system achieved economic benefits of 5 000 yuan/ha, which is 2 206 and 4 274 yuan/ha more than those who adopted a no-tillage without duck technique and a conventional-tillage without duck technique, respectively. 【Conclusion】The rice-duck ecological system not only increased the economic benefits of farmers, but also reduced methane emission in rice paddy field A sustainable agricultural production mode is formed.