Effects of Biochar on Methane Emissions and Crop Yields in East Asian Paddy Fields: A Regional Scale Meta-Analysis

Biochar emerged as a potential solution to mitigating greenhouse gas emissions, though previous studies obtained variable results regarding its effects on methane (CH4) emissions and crop yields. Global meta-analyses were conducted regarding the effectiveness of biochar, though regional meta-analyses are still needed. We performed a meta-analysis of 43 published papers to obtain the central tendency of the response to biochar application in East Asian rice paddies. Biochar application significantly reduced methane emissions while increasing the soil organic carbon (SOC) content and crop yield. We identified the most significant influencing factors on the CH4 emissions, SOC content, and crop yield. Our findings provide a scientific basis for the application of biochar to East Asian rice paddies, as well as to study the effects of biochar application in East Asian rice paddies. The numbers in parentheses represent the sample sizes.