Engineered biochar effects on methane emissions and rice yield under alternate wetting and drying in paddy soils
Year: 2025
Type: article
Abstract: Biochar is a promising strategy for improving crop yield and mitigating greenhouse gas emissions. However, the impacts of acid modified biochar on CH 4 emissions and yield in rice fields are not comprehensively understood, especially under alternate wetting and drying irrigation (I AWD ). Here, we conducted a 3-yr field experiment with two irrigation regimes (I CF : continuous flooding irrigation, I AWD ) and three biochar treatments (B 0 : no biochar; B 20 : 20 t ha -1 rice straw biochar; and B 20A : 20 t ha -1 acid modified rice straw biochar). Results showed I AWD reduced CH 4 emissions by 63-80% and water consumption by 10-12% but threatened the rice soil fertility. B 20 and B 20A increased soil cation exchange capacity by 13-36%, soil organic carbon by 24-44% and C/N by 17-36% over the three years. However, compared to B 0 , B 20 tended to increase CH 4 emissions and factor (CH 4EF ), reduced grain yield by 6% in 2019, but B 20A suppressed CH 4 emissions by 19% while maintaining a stable grain yield. B 20 and B 20A enhanced yield by 5% and 8%, 11% and 12% and decreased CH 4 emissions by 22% and 38%, 38% and 40% in 2020 and 2021, respectively. B 20A alleviated its initial negative impact on CH 4 emissions and yield in 2019 due to acid modified biochar enhancing more acidic and oxygenated functional groups. I AWD B 20A decreased CH 4 emissions by 75-89% and greenhouse gas emission intensity (GHGI) by 75-90% compared to I CF B 0 over the three years. Consequently, B 20A coupled with I AWD achieves sustainable use of water resources, improves soil degradation and mitigates climate change. • Yield is threatened by lower soil fertility under I AWD . • Biochar can improve soil fertility and yield, and reduce CH 4 emissions. • The initial incorporation of fresh biochar increase the risk of CH 4 emissions. • Acid modified biochar alleviates biochar initial yield decrease and CH 4 emissions.
Language: English
Subfield: Soil Science
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $2,930
Funders: National Natural Science Foundation of China, Ministry of Education of the People's Republic of China, Korea University, China Postdoctoral Science Foundation, Ministry of Trade, Industry and Energy, National Research Foundation of Korea, China Scholarship Council, Liaoning Revitalization Talents Program, Chinese Government Scholarship
OpenAlex ID: W4408218976