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

• Published in: The Science of the total environment Vol. 806; no. Pt 4; p. 150789
• Main Authors: Wang, Hao, Nan, Qiong, Waqas, Muhammad, Wu, Weixiang
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.02.2022
• Subjects: Biochar stability; Carbon Sequestration; Charcoal; Environmental factors; Evaluation models; Minerals; Soil; Biochar stability; Environmental factors; Evaluation models; Carbon sequestration
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2021.150789

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 evaluation of physical and chemical properties, and utilization of kinetic mineralization models on the basis of laboratory 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 biochar 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 experiment is strongly recommended to establish a more accurate assessment model on biochar stability for the evaluation of its carbon sequestration potential in mineral soils. [Display omitted] •The dual-pool model is an important method for biochar stability evaluation.•Aging process in field affects biochar stability.•The dual-pool model is actually environment-confined accuracy.•Environmental factors are critical for biochar stability projection.