A Comprehensive Review of Biochar: Boon to Soil Health and Climate Change Mitigation

Abstract

A carbon-rich solid made by pyrolyzing biomass, biochar has become a versatile amendment that can improve the physicochemical characteristics of soil and support long-term climate mitigation plans. Owing to its high porosity, aromatic carbon structure, and physicochemical stability, biochar exhibits a strong capacity to enhance soil physical, chemical, and biological properties. This review critically synthesizes recent scientific evidence on the mechanisms through which biochar improves soil structure, nutrient retention, microbial activity, and water-holding capacity, thereby contributing to improved crop productivity and soil resilience. The analysis carefully evaluates biochar's capacity to mitigate non-CO2 greenhouse gasses (N2O and CH4) from agricultural soils as well as long-term carbon sequestration.The review also evaluates biochar’s effectiveness in remediating contaminated soils through the immobilization of heavy metals and organic pollutants. Despite its demonstrated benefits, large-scale adoption of biochar remains constrained by factors such as feedstock variability, production costs, and the lack of standardized characterization protocols. The paper concludes by highlighting future research priorities and management strategies aimed at optimizing biochar systems for sustainable soil management, climate resilience, and circular bioeconomy integration.