Biochar: A Black Carbon for Sustainable Agriculture

Abstract

Biochar refers to the black carbon that is produced by the process of slow pyrolysis and act as a vehicle of carbon sequestration from renewable and sustainable biomass. This review describes the ability of biochar to improve the physical, chemical and biological properties of soil and thus increase crop yield and productivity. Benefits of application of biochar also includes lowering of bulk density, improving porosity, aggregation, water infiltration and water holding capacity of soils. It also darkens the soil colour which affects soil surface reflectance and thus helps to moderate soil temperature. Biochar addition enhances cation exchange capacity, increases soil pH, improves the supply and uptake of nutrients, reduces nutrient leaching losses, captures NH3 and leads to reduction in volatilization loss of nitrogen thus improving nutrient availability in soils. Application of biochar can also remediate soils contaminated with heavy metals and organic pollutants. It can also facilitate microbial colonisation in soil, enhance soil microbial biomass carbon, enzyme activity and the activity of mycorrhizal fungi.