Stability of biochar in mineral soils: Assessment methods, influencing factors and potential problems

Amendment of biochar into mineral soils has been reported a promising strategy for carbon sequestration and greenhouse gas mitigation due to its high stability. Currently, most studies on the stability of biochar are mainly focused on the assessment methods and influencing factors. The assessment methods include qualitative evalu-ation of physical and chemical properties, and utilization of kinetic mineralization models on the basis of labora-tory incubation. As a result, these assessment methods are difficult to accurately reflect the real impact of the interaction between biochar and environmental factors. This article reviews the existing assessment methods, influencing factors, and the impact of environmental aging on the stability of biochar. It is found that under the influence of environmental factors, existing assessment methods are likely to overestimate the stability of bio -char in mineral soils. Therefore, more emphases should be laid on the analyses of the deficiencies in the existing assessment methods on the stability of biochar in the consideration of practical applications. Long-term field ex-periment is strongly recommended to establish a more accurate assessment model on biochar stability for the evaluation of its carbon sequestration potential in mineral soils. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

The stability of biochar in mineral soils is affected by various factors, and existing assessment methods tend to overestimate its stability. Long-term field experiments are recommended to establish a more accurate assessment model for evaluating biochar's carbon sequestration potential.