Effects of biochar application on soil greenhouse gas fluxes: a meta‐analysis |
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| Authors: | Yanghui He Xuhui Zhou Liling Jiang Ming Li Zhenggang Du Guiyao Zhou Junjiong Shao Xihua Wang Zhihong Xu Shahla Hosseini Bai Helen Wallace Chengyuan Xu |
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| Institution: | 1. Coastal Ecosystems Research Station of Yangtze River Estuary, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, The Institute of Biodiversity Science, School of Life Sciences, Fudan University, Shanghai, China;2. Tiantong National Field Observation Station for Forest Ecosystem, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China;3. Center for Global Change and Ecological Forecasting, East China Normal University, Shanghai, China;4. Environmental Futures Research Institute, School of Natural Sciences, Griffith University, Nathan, Brisbane, Qld, Australia;5. Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore, DC, Qld, Australia;6. School of Medical and Applied Sciences, Central Queensland University, Bundaberg, Qld, Australia |
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| Abstract: | Biochar application to soils may increase carbon (C) sequestration due to the inputs of recalcitrant organic C. However, the effects of biochar application on the soil greenhouse gas (GHG) fluxes appear variable among many case studies; therefore, the efficacy of biochar as a carbon sequestration agent for climate change mitigation remains uncertain. We performed a meta‐analysis of 91 published papers with 552 paired comparisons to obtain a central tendency of three main GHG fluxes (i.e., CO2, CH4, and N2O) in response to biochar application. Our results showed that biochar application significantly increased soil CO2 fluxes by 22.14%, but decreased N2O fluxes by 30.92% and did not affect CH4 fluxes. As a consequence, biochar application may significantly contribute to an increased global warming potential (GWP) of total soil GHG fluxes due to the large stimulation of CO2 fluxes. However, soil CO2 fluxes were suppressed when biochar was added to fertilized soils, indicating that biochar application is unlikely to stimulate CO2 fluxes in the agriculture sector, in which N fertilizer inputs are common. Responses of soil GHG fluxes mainly varied with biochar feedstock source and soil texture and the pyrolysis temperature of biochar. Soil and biochar pH, biochar applied rate, and latitude also influence soil GHG fluxes, but to a more limited extent. Our findings provide a scientific basis for developing more rational strategies toward widespread adoption of biochar as a soil amendment for climate change mitigation. |
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| Keywords: | biochar carbon dioxide global warming potential methane nitrous oxide soil greenhouse gas |
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