中国粮食生产的温室气体减排策略以及碳中和实现路径

Mitigation Strategies of Greenhouse Gas Emissions from Crop Production in China and the Pathways to Agricultural Carbon Neutrality

作为世界上最大的农业生产国和温室气体排放国,我国承诺力争到2030年前实现碳达峰,2060年前实现碳中和。国家“双碳”目标给农业生产带来很大的减排挑战,因为农业源温室气体排放约占我国碳排放总量的14%。粮食生产是农业源非CO_(2)温室气体的主要排放源,归因于过量灌溉和施肥引起的稻田甲烷(CH_(4))和土壤氧化亚氮(N_(2)O)排放。在碳达峰后,粮食生产温室气体的排放占比和减排重要性将越来越大。我国粮食生产究竟能否实现碳中和,以及如何实现碳中和仍不明确。本文综述了我国粮食生产碳排放的源汇效应和时空特征,总结了稻田CH_(4)和土壤N_(2)O减排以及农田土壤固碳的有效措施,解析了固碳减排之间的“此消彼长”效应和应对策略,明确了粮食生产实现碳中和的潜在路径,并对未来固碳减排的研究方向进行了展望。

As the largest agricultural country and emitter of greenhouse gas(GHG)in the world,China aims to peak its emissions before 2030 and achieve carbon neutrality before 2060.This target imposes challenging mitigation demands on agricultural systems,which account for~14%of China’s national GHG emissions.Crop production is a major contributor to agricultural non-CO_(2)GHG emissions,primarily due to high methane(CH_(4))and nitrous oxide(N_(2)O)emissions from intensive use of irrigation water and fertilizers.After the achievement of carbon peak,the contribution of GHG emissions from crop production and the associated mitigation necessity will become increasingly important.It is unclear whether and how crop production can transition to carbon neutrality.This paper reviewed the source and sink effects as well as the temporal and spatial characteristics of GHG emissions from crop production in China,summarized the effective agricultural management practices in mitigating CH_(4)and N_(2)O emissions and enhancing soil organic carbon sequestration,analyzed the trade-offs between GHG mitigation and carbon sequestration and the associated countermeasures,and put forward prospects and suggestions on future studies regarding this research area in China.