Biochar, the solid product of biomass pyrolysis, has been widely used to mitigate global climate change by storing carbon (C) and regulating the transformation of nitrogen (N) in soil. While the effects of biochar on soil C and N cycles, such as mineralization and plant uptake, have been extensively reported, most studies of these types have employed measurement of the changes in total C and N in soil following biochar addition. However, this does not allow for the determination of the sources of C and N in soil that are utilized or transformed. Isotope technology has great potential in evaluating the effects of biochar on the biogeochemical behavior of soil C and N because it can distinguish added biochar C and N from native C and N and other sources of organic matter and determine the transformation or loss rate of each source. However, at present, most studies on this aspect are scattered and the conclusions are inconsistent. Therefore, a systematic review of studies using the C and N isotopes in biochar research is needed. In this paper, the advantages and disadvantages of the application of C and N isotopes to biochar research are summarized, and the findings of these studies as related to the effects of biochar on soil C and N cycles were reviewed, including biochar and native C persistence, CO and NO emissions, and plant N uptake. Finally, some recommendations for future directions on C and N isotopes in the field of biochar research are made. This review could lay a theoretical foundation and encourage the application of C and N isotope technology to the field of biochar research.

中文翻译：

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C和N同位素在土壤中生物炭生物地球化学行为研究中的应用：综述


生物炭是生物质热解的固体产物，通过储存碳（C）和调节土壤中氮（N）的转化，已被广泛用于缓解全球气候变化。虽然生物炭对土壤碳和氮循环（例如矿化和植物吸收）的影响已被广泛报道，但大多数此类研究都采用了测量添加生物炭后土壤中总碳和氮的变化。然而，这并不能确定土壤中被利用或转化的碳和氮的来源。同位素技术在评估生物炭对土壤碳和氮的生物地球化学行为的影响方面具有巨大潜力，因为它可以区分添加的生物炭碳和氮与天然碳和氮以及其他有机质来源，并确定每个来源的转化或损失率。但目前这方面的研究大多比较分散，结论也不一致。因此，需要对生物炭研究中使用 C 和 N 同位素的研究进行系统回顾。本文总结了C、N同位素在生物炭研究中应用的优缺点，并综述了生物炭对土壤C、N循环影响的研究成果，包括生物炭和天然C持久性、CO 和 NO 排放量以及植物氮吸收量。最后，对生物炭研究领域C和N同位素的未来方向提出了一些建议。该综述可为C、N同位素技术在生物炭研究领域的应用奠定理论基础。