Meta-Analysis of the Effects of Different Farming Measures on Greenhouse Gas Emissions from Farmland in China

Reducing greenhouse gas (GHG) emissions from agricultural fields is crucial for mitigating climate change and promoting sustainable agriculture. This study conducted a meta-analysis of 82 domestic experimental studies to assess the effects of fertilization, tillage, and straw return on CH 4 , CO 2 , and N 2 O emissions across different regions in China. The key findings include: fertilization measures: split fertilization increased CH 4 and N 2 O emissions, whereas a single application had the strongest impact on CO 2 emissions. The application of carbon alone or in combination with NPK reduced GHG emissions, while the combination of nitrogen and farmyard manure significantly increased CH 4 and CO 2 emissions. Tillage measures: tillage generally reduced CH 4 and CO 2 emissions but increased N 2 O emissions. No-tillage effectively suppressed CH 4 emissions, while rotary tillage significantly reduced CO 2 emissions. Straw return: straw returning through rotary tillage led to the highest increase in CH 4 and CO 2 emissions, whereas direct straw return most notably enhanced N 2 O emissions. This study provides insights into optimizing agricultural practices to mitigate GHG emissions and offers guidance for sustainable and low-carbon agricultural development.