Geographic Inventory Framework for estimating spatial pattern of methane and nitrous oxide emissions from agriculture in Alberta, Canada

Agricultural systems are important sources of the global carbon and nitrogen cycle and are also non-point sources of nitrous oxide (N2O) and methane (CH4) emissions. The objectives of this paper are to develop a Geographic Inventory Framework (GiF) for spatially-explicit estimation and mapping of agricultural N2O and CH4 emissions for the province of Alberta, Canada. The GiF consists of a modelling component, a Geographic Information Systems (GIS) component, and interconnecting Python software to communicate between the model, GIS database and census data. The results show that methane emissions from enteric fermentation (247.04 Gg) prevail over those from manure (20.39 Gg). Nitrous oxide emissions from manure (8.89 Gg) are comparable to those from soil (11.02 Gg). Cattle emit most N2O and CH4 followed by plant N2O emissions and pigs CH4 emissions. The GIS maps show hot-spots and discernible patterns of N2O and CH4 emissions increasing from north and west to central Alberta, then slightly declining to south and east, which could be useful for addressing mitigation strategies. The advantages of this framework keep the IPCC approach simple, open, transparent and comparable. The explicit inventory provides an accounting of complete greenhouse gas (GHG) balance of agricultural ecosystems and their source/sink strengths, affected by soil, water and climate. This provides an easy-to-use tool to integrate national statistical data, GIS and GHGs analysis for decision-making and policy in ecosystem service and sustainable agricultural management.