Biochar or pyrogenic carbon, obtained from thermo-chemical conversion of
biomass in an anaerobic or oxygen limited environment has been in use in
agriculture since long back to Neolithic era. Its unique soil
ameliorating properties, render it suitable for environmental
remediation as well as sustainable crop production. It improves soil
physicochemical properties and plant nutrient availability, facilitates
biodiversity, and reduces emission of greenhouse gases, thereby
subsiding global warming. Application of biochar reduces soil erosion,
improves soil hydrological properties, and soil microbial dynamics. It
has synergistic effects on plant growth, disease-pest resistance, and
crop yield per unit area and time. Due to its soil ameliorative effects,
and soil and water conserving ability, it can very well be used in
organic farming, pemaculture, dryland farming, conservation agriculture,
and land remediation. Cheaper production cost, simple and easy pyrolytic
technologies, easy availability of feedstock and bio-wastes in many
developing countries and its long-term effects in soil not only build up
soil carbon pool but also help support small and marginal farmers in
resource-rich but economically deprived countries for sustainable
agriculture and environment. In this review, efforts have been made to
elucidate various methods of biochar synthesis, its characteristics and
effects on soil properties, and plant growth and development, its role
in sustainable agriculture and remediation of the environment.