Greenhouse gas emission from rice and wheat-growing areas in India: Spatial analysis and upscaling

The intensified rice and wheat cropping systems consume most of the fertilizer and irrigation water in India and are major sources of greenhouse gas (GHG) emissions. The InfoCrop simulation model was evaluated to calculate methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2) emissions from soils under rice and wheat. Indian rice fields covering 42.21 million ha (Mha) emitted 2.07, 0.02, and 72.9 Tg of CH4-C, N2O-N and CO2-C, respectively, with a global warming potential (GWP) of 88.5 Tg CO2-C eq. Annual GHG emission from 28.08 Mha of wheat-growing areas was 0.017 and 43.2 Tg of N2O-N and CO2-C, respectively, with a GWP of 44.6 Tg CO2-C eq. Intermittent irrigation in rice reduced methane emissions by 40%. However, application of farmyard manure in rice increased the GWP by 41%. This study suggests that the InfoCrop model could be applied for simulating the impacts of crop management and soil and climatic parameters on GHG emission from agricultural areas