Carbon sequestration in soil from paddy straw derived biochar in India

The present research aimed to quantify the environmental benefits of the paddy straw - biochar system for carbon sequestration in India. The estimates showed that 135.5 ±1 MT of gross paddy straw is annually produced in the country, of which 41 ±1.1 MT is burned in-situ. In-situ burning of paddy straw releases 47,336±680 Gg pollutants having a 71.7 ±1.1 MT CO2e environmental footprint. Biochar conversion has been considered an alternative to the in-situ burning of paddy straw and estimated that 16.8±0.5 MT of biochar could be produced from available paddy straw. Biochar application in paddy fields could sequestrate 66.2±1.2 MT CO2e carbon, reduce 62,798±18,624 T NPK fertilizer consumption & 0.63±0.12 MT N2O & CH4 emissions and increase 0.6±0.14 MT CO2 emissions from paddy cultivation. paddy straw collection, field transportation, biochar conversion, material handling and spreading would impart a 21.9±0.8 MT CO2e environmental footprint. Overall, biochar conversion of paddy straw and its application in soil for carbon sequestration could reduce 135.6±4.5 MT CO2e environmental footprint from paddy cultivation which is about 6 % of annual GHG emission from India in 2019. The results of the present study would help develop an environment-friendly and sustainable management system for paddy straw in the country.