Increasing soil organic carbon (SOC) in agricultural systems is a primary nature-based option for mitigating climate change, improving soil fertility, and ensuring food security. However, the consequences of global warming and increases in carbon inputs on cropland SOC stocks over the last few decades remain largely unknown, particularly in deeper soil layers. Here, by using repeated measurements, we reassess variations in SOC stocks across a 0 to 100 cm soil profile at the same locations in China’s upland croplands in 1980 and 2023. We observe an overall net accumulation of 0.74 Pg SOC (7%) with a mean sequestration rate of 13.7 g SOC m ⁻² y ⁻¹ . This accumulation results from 0.86 Pg SOC gains at upper soil depths (0 to 60 cm) induced by carbon inputs, alongside 0.12 Pg SOC losses at deeper soil layers (60 to 100 cm) prompted by warming-enhanced decomposition. While our findings indicate a successful, though lower than expected, increase in overall net SOC stocks, the loss of more recalcitrant deeper SOC warrants further consideration of its effects on enhancing cropland SOC accumulation to achieve carbon neutrality over the long term.

Water and fertilizer management practices are considered to have great influence on soil methane (CH₄) emissions from paddy fields. However, few studies have conducted a quantitative analysis of the effects of these management practices. Here, we selected 156 observations of water management from 34 articles and 288 observations of fertilizer management from 37 articles and conducted a global meta-analysis of the effects of water and fertilizer management practices on soil CH₄ emissions in paddy fields. In general, compared with traditional irrigation (long-term flooding irrigation), water-saving irrigation significantly decreased soil CH₄ emissions but increased rice yield. Among the different practices, intermittent irrigation had the fewest reductions in CH₄ emissions but the greatest increase in rice yield. In addition, fertilization management practices such as manure, mixed fertilizer (mixture), and straw significantly enhanced CH₄ emissions. Rice yields were increased under fertilization with a mixture, traditional fertilizer, and controlled release fertilizer. Our results highlight that suitable agricultural water and fertilizer management practices are needed to effectively reduce CH₄ emissions while maintaining rice yields. We also put forward some prospects for mitigating soil CH₄ emissions from paddy fields in the context of global warming in the future.