Use of Biochar for Soil Health Enhancement and Greenhouse Gas Mitigation in India Potential and Constraints

Abstract

It is crucial to maintain a threshold level of organic matter in the soil for maintaining physical, chemical and biological integrity of the soil and for sustained agricultural productivity. Efficient use of biomass by converting it as a useful source of soil amendment/nutrients is one way to manage soil health and fertility. The current availability of biomass in India is estimated at about 500 million tons/year. These residues are either partially utilized or un-utilized due to various constraints. It is estimated that about 93 million tons of crop residues are burned in each year in India. Residue burning traditionally provides a fast way to clear the agricultural field of residual biomass, facilitating further land preparation and planting. However, in addition to loss of valuable biomass and nutrients, biomass burning leads to release of toxic gases including GHGs. In this context, biochar, a pyrolysis product of plant biomass offers a significant, multidimensional opportunity to transform large scale agricultural waste streams from a financial and environmental liability to valuable assets. Use of biochar in agricultural systems is one viable option that can enhance natural rates of carbon sequestration in the soil, reduce farm waste and improve the soil quality. Biochar has the potential to increase conventional agricultural productivity and mitigate GHG emissions from agricultural soils. This has led to renewed interest of agricultural researchers to produce biochar from bioresidues and its use as a soil amendment. Although many countries have prioritized the use of biochar in agricultural systems, studies on biochar production and its utilization as a soil amendment are at a nascent stage in India. In addition to public organizations, many private institutes and NGOs have initiated work on these lines. This bulletin documents the initial outcomes of biochar research being conducted in different parts of the country, and potential benefits of biochar use in improving soil health, crop productivity and in mitigating climate change through reduction in emission of GHGs and carbon sequestration. We firmly believe that this publication will be very useful for researchers, academicians, policy makers and students.