Carbon footprint and agricultural sustainability nexus in an intensively cultivated region of Indo-Gangetic Plains.

Green Revolution led to an unprecedented increase in world food production but with a significant carbon footprint raising concerns about its sustainability. With the rising global population and the need to produce more food, the farming systems will have to be sustainable. To identify farming practices that increase yield with minimum environmental cost, it is imperative to quantify the environment footprint of different technologies. The present study quantified the impact of Green Revolution technologies on the carbon footprint of intensive crop production systems, mainly rice-wheat in an agriculturally important region of Indo-Gangetic Plains. The results revealed the overriding importance of groundwater irrigation and fertilizer use in determining the carbon footprint of crop production, and underpin the opportunities for their mitigation. Intensification of agriculture resulted in ~2.5 fold increase in food grain production and 3-fold increase in emission of greenhouse gases (GHGs) during 1980 to 2015. Carbon sustainability of food grain production declined with time indicating that energy use efficiency is decreasing; the greatest decline being in rice followed by wheat and negligible in maize. Options for mitigating environment footprint of food grain production included partially replacing area under rice with other less water requiring crops, improving irrigation water productivity and pumping efficiency, and increasing fertilizer use efficiency. Maize with low global warming potential and high C sustainability appeared a viable option for diversification. The implementation of these mitigation measures can reduce environment footprint by 46%. Preventing crop residue burning will not only offset the associated GHG emissions (6266 Gg yr) but can also improve soil health if returned to the soil. Intensification of agriculture has co-benefit of C sequestration in soil, which besides offsetting emissions by ~10% is an important determinant of soil quality and sustainability.