A review of the impact of biochar on the soil-plant system and pollutant mitigation

Abstract

Biochar, a carbon-rich material, is increasingly recognized for its multifaceted role in enhancing agricultural sustainability, soil health, and ecosystem service delivery. Its physicochemical properties, governed by feedstock selection and pyrolysis parameters, have a significant impact on soil structure, cation exchange capacity, water retention, and microbial activity, which directly affects crop productivity; affected by various factor like soil type, climatic conditions, and crop type. Beyond its agronomic benefits, biochar serves as a critical tool for climate change mitigation and soil remediation. Evidence demonstrates that biochar application can suppress greenhouse gas emissions and facilitate the immobilization of heavy metals (e.g., As, Cd, Hg, Pb, Zn) through adsorption, ion exchange, and chelation. Furthermore, it shows great promise in the immobilization of organic contaminants, including pesticides and polyaromatic hydrocarbons, via enhanced hydrophobic interactions and degradation through microbial stimulation. Additionally, biochar functions as a potential biocontrol agent, reducing the incidence of soil-borne and foliar pathogens by fostering a suppressive soil environment. While the efficacy of biochar varies based on pollutant type, soil composition, crop type, climatic conditions, and production conditions, its potential to promote long-term bioremediation and sustainable food production is substantial.