Gaseous emissions from agricultural activities and wetlands in national capital territory of Delhi

This work aims to develop an emission inventory of methane (CH4), nitrous oxide (N2O), ammonia (NH3), nitrogen oxides (NO, NO2) and CO2 from various agricultural activities and wetlands in Delhi area using an emission factor and activity based approach between the years 2001 and 2011. Among all agricultural activities, livestock enteric fermentation (LEF) was found to be the main source, contributing up to 90% of total CH4. This is followed by livestock manure management (LMM) (6-7%), paddy field (3-5%) and burning of crop residue (0.6-0.9%). It was also found that LMM practices alone contributed ∼99.8% of total N2O emissions and ∼106-141 Gg of NH3 during 2001-2011. Crop residue burning was responsible for ∼41 Gg of annual average emissions of NOx over the period 2001-2011. Annual CH4 emissions from rice cultivation practices were found to be in the 560-634 Gg range during same period. N2O emission from crop residue burning and fertilizer were insignificant when compared with LMM practices. About 54 Gg, 1.5 Gg and 14 Mg of CO2, CH4 and N2O, respectively, were released by natural and manmade wetlands in Delhi during 2009 while manmade wetlands were found to be responsible for 48-49% of total GHG (CO2,CH4,N2O) emissions.