日本长期不同施肥稻田N2O和CH4排放特征及其环境影响

观测了75年长期连续不施肥、施硫酸铵、施熟制水稻秸秆与豆饼混合堆肥、施绿肥苜蓿4种处理下日本单季稻田温室气体N₂O和CH₄的排放特征及其环境影响.结果表明： 在水稻生长季节，不同处理间N₂O排放无显著差异，但CH₄排放差异显著；长期连续施用有机肥虽然没有增加N₂O排放却促进了CH₄排放.各系统排放N₂O和CH₄所产生的累积全球增温潜势（GWP）以绿肥处理最大（310.7 g CO₂e·m^-2），熟制有机堆肥次之（151g CO₂e·m^-2），硫酸铵处理最小（60.6 g CO₂e·m^-2）.稻田系统的GWP主要来自CH₄排放，控制和减少稻田系统CH₄排放是稻田温室气体减排的核心问题.长期连续施用熟制有机堆肥既能增加土壤有机质，改善地力，满足水稻高产，又能实现CH₄减排，是实践中值得推荐的水稻生产模式.

N2Oand CH4emission from Japan rice fields under different long-term fertilization patterns and its environmental impact..

This study intended to investigate the greenhouse gases emission from Japan single cropping paddy fields after 75-year continuous application of ammonium sulfate, composted rice straw with soybean cake, and fresh clover, as well as the environmental impact of the emission. During this long period, field management remained constant in terms of rice cultivation density, irrigation, and equivalent net N fertilization. No significant differences were observed in N₂Oemission among the fertilization treatments, but the CH₄emission differed significantly between organic amendment and ammonium sulfate application, indicating that long-term organic fertilization didn’t increase N₂O emission but promoted CH₄emission. The cumulative global warming potential (GWP) of the CH₄and N₂Ofrom the paddy ecosystem was the greatest (310.7 g CO₂e·m^-2) under fresh clover application, followed by composted rice straw plus soybean cakeaddition (151 g CO₂e·m^-2), and the least (60.6 g CO₂e·m^-2) under ammonium sulfate application. This study showed that for paddy system, it was CH₄ instead of N₂Othe major factor affecting global warming, and thereby,to control and reduce the CH₄ emission from paddy system would be the core inmitigating greenhouse gases emission from paddy field. Long-term consecutive application of composted rice straw plus soybean cake could increase soil organicmatter, improve soil fertility, promote rice high-yielding, and as well, mitigate CH₄ emission, being the recommendable paddy rice production mode in practice.