Biochar for Soil Acidity Mitigation and Agricultural Sustainability: A Review

More than half of the arable land in the world is impacted by soil acidity that reduces the productivity of crops and availability of nutrients. This review examines biochar as a sustainable solution for mitigating soil acidity and enhancing agricultural productivity. The main research question is the effectiveness of biochar as a means of enhancing the health of soils and stimulating the growth of crops in acidic soils in relation to traditional soil supplements such as lime. A systematic review of peer-reviewed literature focused on studies assessing biochar’s effects on acidic soils. Data were gathered on biochar production (pyrolysis conditions, feedstock types), soil amendment applications, and comparisons with lime. Key parameters included soil pH, nutrient availability, microbial activity, and crop yield. Both immediate and long-term impacts were evaluated through laboratory and field studies. Biochar has been proven to be effective in neutralizing soil acidity by raising the pH of soils and decreasing the toxicity of aluminum because of its alkaline nature and high cation exchange capacity. Compared to lime, biochar offers advantages such as enhanced water retention, increased microbial biomass, and long-term carbon sequestration. Its porous structure promotes root development and nutrient uptake while reducing bulk density. However, its effectiveness depends on factors like feedstock type, pyrolysis temperature, and soil characteristics. Biochar raises pH, sequesters carbon, and enhances microbial biomass, providing a multifaceted alternative to lime. Standardized rate-response equations for different soil orders are still lacking.