Temporal and spatial variability of nitrous oxide emissions from agriculture in Argentina

Agricultural activities constitute the main N2O emission source in Argentina. Although GHG inventories have been developed at the national and provincial level, emissions have not been thus far estimated at a higher spatial resolution. We estimated the time series 2000-2012 of N2O emissions at national, provincial and district levels. National N2O emissions in 2012 amounted to 105.1 Gg (95% CI: 73.0-200.7), with manure deposited on pasture accounting for 59.8%, crop residues 24.0%, N-fertilizers use 14.3%, manure management 1.7% and agricultural waste burning 0.2%. Beef cattle excreta followed by soybean crop residues were the major sources of N2O. The time series of N2O emission estimated at district level allowed identifying the effect of the frequent displacement of crops and livestock indicative of the variability of the intensity and location of the emission sources. The observed annual variability of emissions and the identification of the main drivers indicate the convenience of using surrogate methods to estimate emissions when activity data cannot be acquired on annual basis. This type of inventory would be of interest for decision makers and stakeholders when discussing environmental policies and measures in light of the responsibility of agricultural activities occurring in the territory of their concern.