Journal Article

Sustained Green Manure‐Rice Rotations Can Mitigate Methane Emissions by Enhancing Microbial Methane Oxidation in Southern China

This study was supported by National Key Research and Development Program of China (2021YFD1700200) and National Natural Science Foundation of China (42361144876; 42477374; 42225102), Schmidt, Susanne, Jiangxi Academy of Agricultural Sciences, College of Urban and Environmental Sciences [Beijing] ; Peking University [Beijing], Cao, Weidong, Hunan Agricultural University [Changsha], Gabrielle, Benoît, Huazhong Agricultural University [Wuhan] (HZAU), Chinese Academy of Agricultural Sciences (CAAS), Hohai University, Li, Tao, Anhui Agriculture University (AHAU), Smith, Pete, Zhou, Guopeng, Liang, Hao, Fujian Academy of Agricultural Sciences, Anhui Agricultural University [Hefei], Nie, Jun, Xu, Changxu, The University of Queensland (UQ [All campuses : Brisbane, Dutton Park Gatton, Herston, St Lucia and other locations]), Liu, Jia, International Rice Research Institute [Philippines] (IRRI) ; Consultative Group on International Agricultural Research [CGIAR] (CGIAR), Feng, Jiguang, State Key Laboratory of Efficient Arable Land Utilizatio

2025

Overview

Green manure (GM) enhances the ecological services in agricultural ecosystems, including soil health and carbon sequestration. However, its effect on regional methane (CH 4 ) emissions from paddy fields is unclear. Here we clarify the impacts of GM rotation by combining process-based modeling with microbial gene abundance information and coordinated distributed observations at 14 sites in southern China. We found that GM management, including application rate and rotation year, mainly affects CH 4 emissions in GM-rice systems by impacting soil biotic factors, which explain 78.4% of the variation (p < 0.001). The most influential factor is the ratio of soil CH 4 production to oxidation gene abundances (R 2 = 0.510; p < 0.001), which decreases with GM rotation year due to increased activity of methane-oxidizing soil microbes (p < 0.001), indicating that CH 4 emissions from GM-rice systems decrease with increased GM rotation year. By incorporating these microbial mechanisms as quantitative parameters in process-based model, we project that approximately 76% of the paddy rice areas in southern China, which have relatively low GM biomass and baseline CH 4 emissions, can achieve reductions in CH 4 emissions through nearly 15 years of GM crop rotation. This study indicates that CH 4 emissions from GM-rice rotations with appropriate GM application rate over the long term will not significantly increase, resolving the contradictions in previous research

• Publisher: American Geophysical Union,CCSD,John Wiley & Sons, Inc,Wiley
• Subject: Agricultural ecosystems / Agricultural practices / Agricultural sciences / Agronomy / Biomass / Biotic factors / Carbon sequestration / Chromatography / Crop rotation / Emissions / Environmental Sciences / Genetically altered foods / Global Changes / green manure / Life Sciences / Manures / Methane / Methane emissions / Microorganisms / Oxidation / paddy soil / process‐based modeling / Rice / Rice fields / rotation year / Soil microorganisms