斜发沸石对干湿交替灌溉驱动下稻田甲烷和氧化亚氮排放的影响机理研究

稻田是CH4和N2O温室气体的重要排放源。为充分发挥干湿交替灌溉技术的节水效果和对稻田CH4气体排放的抑制作用，解决因其频繁干湿交替环境而导致N2O过多的排放，探索斜发沸石对干湿交替灌溉下稻田中CH4和N2O的排放影响机理，本项目拟通过室内离心机试验、土柱试验和蒸渗仪试验，明确沸石用量和粒径对稻田土壤持水性能和保水潜力的影响，构建常规淹灌和干湿交替灌溉下土壤含水率和有效氮与沸石用量和粒径之间的关系曲线，阐明稻田应用干湿交替灌溉降低CH4排放的作用机理，探索斜发沸石在土壤水分饱和与非饱和、氧化与还原等干湿交替环境下降低稻田N2O排放的激励机制，阐明其在节水省肥和增产的同时对降低温室气体排放的动力机制，以期实现在减少东北地区稻田水氮资源消耗的基础上，降低水稻生产环境代价，为生态文明建设提供理论依据和技术支撑。

Rice fields have been identified as an important source of atmospheric methane (CH4) and nitrous oxide (N2O). Meanwhile, alternate wetting and drying irrigation (AWD) is the most widely used among various water-saving techniques in rice fields. Enhanced soil oxidation - reduction potential caused by AWD inhibits CH4 emission, but rapid fluctuations in soil moisture, soil redox potential and water-filled pore space under AWD intensify N2O emissions. Addition of zeolite to soil increases soil water holding capacity and nutrient preserving capability, resulting in decline in N2O emission. However, limited information on CH4 and N2O emissions is available for zeolite-amended paddy field under AWD. In this project, a dynamic centrifuge experiment will be conducted to determine effects of application rate and particle size of zeolite on water holding capacity and water retention potential of paddy soils. A laboratory soil column experiment will be used to determine that correlation curve of relationship between application rate and particle size of zeolite, and soil moisture and nitrogen availability under continuous flooding and AWD irrigations. Two lysimeter experiments will be conducted under automatic canopy to reveal influence mechanism that application AWD reduces CH4 emission, and incentive mechanism of zeolite amendment to reduce N2O emission under the rapid fluctuations in soil moisture, soil redox potential and water-filled pore space of AWD. It concludes that it is of importance to conduct this study to clarify the potential of zeolite addition to AWD paddy field to reduce water and fertilizer use and maintain or improve grain yield while lowering CH4 and N2O emissions, providing a theoretical basis and technical support for ecological civilization construction of rice production system.