稻田甲烷减排：技术、挑战与策略

CH4 REDUCTION IN RICE PADDY: TECHNOLOGY, CHALLENGE AND STRATEGY

关键词:  甲烷  稻田  减排  技术  政策

Key words:  methane  rice paddy  reduction  technology  policy

摘要:

目的 甲烷（CH₄）是强效温室气体，减少CH₄排放能有效在近期内减缓全球变暖趋势。稻田是作物系统CH₄主要排放源，中国作为全球最大水稻生产国和消费国，在稻米充分供给和粮食安全下如何有效控制稻田CH₄排放存在挑战。方法 文章系统阐述了国内外稻田CH₄排放现状和估算结果，从灌溉、施肥、品种、耕作、栽培等方面综述主要CH₄减排技术及效果，梳理相关减排政策，分析我国稻田CH₄减排面临的挑战并提出对策建议。结果 （1）中期晒田、节水灌溉是稻田CH₄减排的关键手段，优化施肥管理、改进秸秆/有机物料还田方式、生物炭、低排放品种、水稻直播和种养结合等有助于控制CH₄排放。（2）在保障水稻增产和农民增收前提下，应当创新集成现有稻田CH₄减排技术，加大轻简化减排技术研发推广，构建稻田CH₄排放监测、报告、核查体系和低碳激励机制，加强农业绿色低碳政策引导，并明确CH₄减排路径。结论 通过技术优化、研发创新、宣传引导、监测报告、激励机制有助于实现我国稻田CH₄排放的有效控制，研究结果可为稻田CH₄减排政策制定和水稻绿色低碳生产提供参考。

Abstract:

Methane (CH₄) is a potent greenhouse gas, and the reduction in CH₄ emission can effectively and rapidly mitigate global warming. Rice paddy is the main source of CH₄ emission in cropping systems. China is the largest rice producing and consuming country in the world. How to validly control CH₄ emission in the promise of a stable supply of rice and food security is a challenge at present. In this study, we reviewed the estimation results of global CH₄ emission in rice paddy, summarized the mitigation technologies and their effectiveness from the aspects of irrigation, fertilization, cultivar, tillage and cultivation, and explored the current mitigation polices. Therefore, the challenges regarding to CH₄ reduction in Chinese rice paddy were analyzed, and the strategies and suggestions were proposed. The results indicated that mid-season drainage and water-saving irrigation were the key practices to reduce CH₄ emission from rice paddy. Optimizing fertilization managements, improving straw/organics amendment, application of biochar, low-emission cultivar, direct-seeding rice and combination of rice planting and breeding would contribute to controlling CH₄ emission. Aiming to lower CH₄ emission in the context of increasing rice yield and farmers’ profits, it was recommended to integrate current exiting reduction technologies, develop and popularize innovated and simplified technologies, establish monitoring, reporting, verification system, build up incentive mechanism, strengthen policy guidance for green and low-carbon agriculture, and formulate the national CH₄ reduction pathways. Thus, CH₄ emission from rice paddy can be effectively controlled through technological optimization and innovation, publicity and guidance, monitoring report and incentive subsidy. This study can provide reference for decision-making of CH₄ reduction and green and low-carbon development in rice cultivation.