Climateresilient agriculture and soil organic carbon

Abstract

The soil carbon (C) reservoir is an important component of the global C cycle. It comprises of soil organic C (SOC) and soil inorganic C (SIC). Soils of India are severely depleted of their SOC stock. Therefore, enhancing and maintaining SOC concentration to above the critical threshold (~1.5% in the 0-20cm depth) is essential to im- proving soil quality, increasing use efficiency of nutrients and water, minimizing vulnerability to extreme climatic events, decreasing susceptibility to erosion and other degradation processes, and sustaining agronomic produc- tion. Above all, recarbonization of the SOC stock is integral to any strategy towards adapting to and mitigating the abrupt climate change, advancing food security and improving the environment. The SOC stock is also important to provisioning of numerous ecosystem services (e.g., food security, water security). Thus, identification and adop- tion of recommended management practices (e.g., conservation agriculture, agroforestry, manuring and inte- grated nutrient management, diverse farming system) are important to C sequestration. The rate of SOC seques- tration in cropland soils of India are low, but need to be credibly assessed for diverse soils and farming systems. Rate of formation of secondary carbonates for different practices and or leaching of bicarbonates in irrigated soils must be established. A way forward should consider: (i) improvement in education curricula at state agricultural universities to include courses on climate change, C sequestration etc.; (ii) establishment of National Climate-Re- silient Agriculture Program (NACRAP), and (iii) development of mechanisms to compensate farmers and land managers through payments for ecosystems services (e.g., soil C sequestration).