首页 > 分享 > 干湿交替灌溉对水稻生产和温室气体减排影响研究进展

干湿交替灌溉对水稻生产和温室气体减排影响研究进展

花匠小妙招
2024-11-11 19:30

摘要： 水稻生产消耗了大量淡水资源，同时也是温室气体的重要排放源。水分管理是影响稻田温室气体排放的关键因子，干湿交替灌溉（AWD）作为一种重要的稻田节水减排管理模式，在中国、菲律宾、越南和印度等一些亚洲国家广为应用。本文综述了AWD管理模式对稻田温室气体减排和其他生态效益（节水潜力、水稻产量等）影响的研究进展。总体而言，AWD可显著降低甲烷（CH4）排放，但较大幅度增加了氧化亚氮（N2O）排放，因此，其综合温室气体减排效果取决于N2O增加幅度。水分管理耦合肥料管理，如优化肥料施入种类和方式等，有利于CH4和N2O同时减排。另一方面，AWD设定的土壤水分胁迫阈值影响水稻产量，轻度水分胁迫（土壤水势阈值-15±5 kPa）可在降低灌溉水量的同时保持水稻稳产，而重度水分胁迫（土壤水势阈值-30±5 kPa）时水稻产量显著降低。AWD稻田土壤通气性较好，利于微生物活动，一定程度上促进了土壤有机物质的分解。科学合理地发展节水高效的水稻生产模式，有利于降低生产成本，增加农民经济收益。

关键词: 水分管理, 干湿交替灌溉, 水稻生产, 温室气体减排, 水分胁迫阈值

Abstract: Rice production consumes large amount of water resource and is an important greenhouse gas (GHG) source. Water management in paddy fields is the key factor controlling GHGemission. As an important agricultural practice for water saving and GHG emissions reduction, alternate wetting and drying (AWD) irrigation has been commonly applied in many Asian countries, such as China, Philippines, Vietnam, and India. We analyzed the effects of AWD irrigation on GHG emissions mitigation and other ecological efficiency, including water saving potential and rice yields. AWD significantly decreased methane (CH4) emission and increased nitrous oxide (N2O) emission. The global warming potential (GWP) mitigation was dependent on the increases of N2O emission. Coupling with fertilizer management, such as optimizing the fertilizer type and application method, AWD is conducive to the CH4 and N2O mitigation. Rice yield was affected by the water stress threshold of AWD. Mild water stress (field was re-flooded when soil water potential dropped to -15±5 kPa) could reduce irrigation water inputs and maintain rice yield, while severe water stress (field was re-flooded when soil water potential dropped to -30±5 kPa) significantly reduced yield. AWD improved soil aeration and microbial activities, with positive impacts on decomposition of soil organic matter. Encouraging farmers to develop watersaving and efficient agriculture scientifically would be beneficial to cost reduction and income increase.

Key words: water management, alternate wetting and drying irrigation, rice production, greenhouse gas emissions mitigation, water stress threshold.