水分和秸秆管理减排稻田温室气体研究与展望

水稻生产过程是人为源温室气体甲烷(Methane,CH4)和氧化亚氮(Nitrous oxide,N2O)的重要排放源,稻田中CH4和N2O的产生与排放受农事管理与环境因素影响,尤其是水分管理和秸秆还田措施,直接影响稻田土壤氧化还原状况和土壤中易分解有机质的含量,对稻田CH4和N2O的排放具有显著的影响效果。很多研究结果表明,控制灌溉、干湿交替等节水灌溉措施能显著降低CH4排放量,但同时也可能促进N2O的排放,因此如何同时减少CH4和N2O的排放量是实现稻田温室气体减排的关键所在;另外,秸秆还田在改良土壤肥力的同时也增加了外源性有机质的输入,促进了稻田CH4的排放。如何优化秸秆还田措施,并耦合水分管理以达到土壤改良和温室气体减排的双重效益对稻田系统的可持续利用至关重要。本文从水分管理、秸秆管理、以及水分和秸秆协同管理等几个方面综述了近年来稻田温室气体减排的研究进展,重点总结了国内外通过水分管理减排稻田温室气体的效果、水分与施肥耦合的减排效果、秸秆还田措施以及水分管理与秸秆还田耦合对稻田温室气体排放的影响,并对今后稻田温室气体减排的研究方向作了展望。

Research progress and prospects of water and crop residue managements to mitigate greenhouse gases emissions from paddy field

Rice production is an important emission source of anthropogenic greenhouse gases methane(CH₄)and nitrous oxide(N₂O). The production and emission of CH₄ and N₂O in paddy field are affected by agricultural management and environmental factors, especially water management and straw returning measures, which directly affect the redox status of paddy soil and the content of decomposed organic matter in soil. Both water and straw management measures have significant effect on the CH₄ and N₂O emission in paddy field. Many research results show that water management measures, such as controlling irrigation and alternate wetting and drying can significantly mitigate CH 4 emission, but may also promote N₂O emission. Hence, how to mitigate CH₄ and N₂O emissions simultaneously is the key factor to achieve greenhouse gases emission mitigation in paddy fields. On the other hand, straw returning can improve the soil fertility of paddy fields and increase the exogenous carbon source, which promotes CH₄ emission in paddy field. How to optimize the straw returning measures, coupling with water management, to achieve the co-benefits of soil improvement and greenhouse gases emission mitigation is very important for sustainable utilization of paddy field. In this paper, the research progress of greenhouse gases emission mitigation in paddy field in recent years is reviewed from the aspects of water management, straw management and water and straw collaborative management in paddy field. The research results of the effect of water management, water management coupling with fertilizer application on greenhouse gases mitigation in paddy field, and the effect of straw returning and water management coupling straw returning on greenhouse gases emission in paddy field are summarized. Furthermore, the future research of greenhouse gases emission mitigation in paddy field is prospected.