Biochar-amended soil can further sorb atmospheric CO2 for more carbon sequestration

作者：Xiangyang Gui, Xiaoyun Xu, Zehong Zhang, Liyang Hu, Wenfeng Huang, Ling Zhao, Xinde Cao · 发表于：Communications Earth & Environment · 年份：2025 · DOI：10.1038/s43247-024-01985-5 · 被引用次数：39 · 研究领域：CO2 Sequestration and Geologic Interactions、Carbon Dioxide Capture Technologies、Atmospheric and Environmental Gas Dynamics

Input of biochar into soil is considered as an efficient technology for carbon sequestration. This work is aimed to explore if the extra sorption of carbon dioxide (CO2) exists in the biochar-amended soil, which has not yet received attention. Here we put biochar and mineral-rich biochar into soils to perform laboratory CO2 sorption experiments. Our results demonstrate that all biochar increased soil carbon storage and meanwhile further sorb CO2 for more carbon sequestration. The Ca or Mg originated in biochar could react with more CO2 and eventually be converted into inorganic carbonate minerals in the amended soil. Further, the country-level prediction showed that all cultivated top soils with biochar application in China could achieve 7.38–12.5 billion tons of carbon sequestration and an additional 0.34–2.66 billion tons of CO2 sorption. The results require us to take into consideration of both carbon sink and extra CO2 sorption in the assessment of biochar carbon sequestration potential in soil. Application of [5%] biochar to soil could sequester around 10 billion tons of carbon in China’s soils, according to laboratory sorption experiments with pristine soil and four different biochar applications.