Rice paddy soils are a quantitatively important carbon store according to a global synthesis

This is the final version. Available on open access from Nature Research via the DOI in this recordData availability: The datasets generated during the current study are available at https://doi.org/10.5281/zenodo.5102775Rice paddies account for ~9% or the world’s cropland area and are characterized by environmental conditions promoting soil organic carbon storage, methane emissions and to a lesser extent nitrous oxide emissions. Here, we synthesize data from 612 sites across 51 countries to estimate global carbon stocks in paddy soils and determine the main factors affecting paddy soil carbon storage. Paddy soils (0–100 cm) contain 18 Pg carbon worldwide. Paddy soil carbon stocks decrease with increasing mean annual temperature and soil pH, whereas mean annual precipitation and clay content had minor impacts. Meta-analysis shows that paddy soil carbon stocks can be increased through several management practices. However, greenhouse gas mitigation through paddy soil carbon storage is generally outweighed by increases in methane and nitrous oxide emissions. Our results emphasize the key role of paddies in the global carbon cycle, and the importance of paddy management in minimizing anthropogenic greenhouse gas emissions.National Key Research and Development programNational Natural Science Foundation of ChinaNatural Science Foundation of Hunan ProvinceYouth Innovation Team Project of Institute of Subtropical Agriculture, Chinese Academy of SciencesInternational Postdoctoral Exchange Fellowship Program 2018European Research Council (ERC)Alexander von Humboldt FoundationWong Magna Fund, Ningbo Universit