Soil pH Determines Nitrogen Effects on Methane Emissions From Rice Paddies

作者：Junqi Tang, Haoyu Qian, Xiangcheng Zhu, Zhuoshu Liu, Yakov Kuzyakov, Jianwen Zou, Jinyang Wang, Qiang Xü, Ganghua Li, Zhenghui Liu, Songhan Wang, Weijian Zhang, Jun Zhang, Shan Huang, Yanfeng Ding, Kees Jan van Groenigen, Yu Jiang · 发表于：Global Change Biology · 年份：2024 · DOI：10.1111/gcb.17577 · 被引用次数：39 · 研究领域：Soil Carbon and Nitrogen Dynamics、Soil and Unsaturated Flow、Atmospheric and Environmental Gas Dynamics

ABSTRACT Rice paddies account for approximately 9% of human‐induced methane (CH 4 ) emissions. Nitrogen (N) fertilization affects CH 4 emissions from paddy soils through several mechanisms, leading to conflicting results in field experiments. The primary drivers of these N‐related effects remain unclear and the contribution of N fertilization to CH 4 emissions from the rice paddies has not yet been quantified for global area. This uncertainty contributes to significant challenges in projecting global CH 4 emissions and hinders the development of effective local mitigation strategies. Here, we show through a meta‐analysis and experiments that the impact of N fertilization on CH 4 emissions from rice paddies can be largely predicted by soil pH. Specifically, N fertilization stimulates CH 4 emissions most strongly in acidic soils by accelerating organic matter decomposition and increasing the activities of methanogens. Accounting for the interactions between soil pH and N fertilization, we estimate that N fertilization has raised current area‐scaled and yield‐scaled CH 4 emissions across the total global paddy area by 52% and 8.2%, respectively. Our results emphasize the importance of alleviating soil acidification and sound N management practices to mitigate global warming.