TitleSoil management for climate-resilient agriculture                                

AbstractClimate change, caused by increase in the concentration of greenhouse gases (GHGs) i.e., carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) in the atmosphere, has emerged as the most prominent environmental issue all over the world. The Inter-Governmental Panel on Climate Change (IPCC), in its 5th Assessment Report (2014) reiterated that the warming of the climate system is unequivocal. Indian agriculture is highly prone to the risks due to climate change. Agriculture sector is also a major contributor to the enhanced greenhouse effect. Climate change may considerably affect the food supply and access through direct and indirect effects on crops, soils, livestock, fisheries and pests.

Soil is a source and also acts as a sink of GHGs. It is intricately linked to the atmospheric–climate system through the carbon, nitrogen, and hydrologic cycles. Methane is produced in soil during microbial decomposition of organic matter under anaerobic conditions. Rice fields submerged under water are the potential source of CH4 production. Continuous submergence, higher organic C content and use of organic manure in puddled soil enhance the methane emission. Burning of crop residues also contributes to the global methane budget. Nitrous oxide is produced in soils through the processes of nitrification and denitrification.

Soil management offers opportunities for mitigation from supply-side and also from demand-side. The emissions can be effectively minimized by better soil-water-fertilizer-crop management interactions both under irrigated as well as rainfed agriculture. The supply-side opportunities include sustainable intensification with improved varieties, diversified crop rotations; improving nutrient, crop residue and water management; reducing emissions from enteric fermentation; reducing methane emissions from rice cultivation and improving manure management. The demand-side opportunities are sequestering carbon in agricultural systems including agro-forestry, bio-energy crops biochar application, reducing food waste and shifting dietary trends.

Soil management offers promises for climate change adaptation through modifying crop management practices, improving water management, adopting new farm techniques such as resource conserving technologies (RCTs), crop diversification and harnessing the indigenous technical knowledge of farmers. Loss of fertile soil and carbon and nitrogen along with eroded soils can be reduced by local specific soil management practices. Though, there are significant opportunities for GHGs mitigation and adaptation in agriculture, but numerous barriers need to be overcome. A win-win solution is to start with such mitigation and adaptation strategies that are needed for sustainable development.