Development and application of a mechanistic model to estimate emission of nitrous oxide from UK agriculture

• Published in: Atmospheric environment (1994) Vol. 36; no. 6; pp. 917 - 928
• Main Authors: Brown, L, Syed, B, Jarvis, S.C, Sneath, R.W, Phillips, V.R, Goulding, K.W.T, Li, C
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.02.2002; Elsevier Science
• Subjects: Agricultural cropland; Applied sciences; Atmospheric pollution; Dispersed sources and other; Exact sciences and technology; Grassland; Greenhouse gas; Inventory; IPCC; Pollution; Pollution sources. Measurement results; United Kingdom; Europe; Grassland; Agricultural cropland; IPCC; Greenhouse gas; Inventory; Sensitivity analysis; Mechanistic approach; Emission content; Pollution source inventory; Air pollution; Agriculture; Nitrogen protoxide; Pollutant emission; Modeling
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/S1352-2310(01)00512-X

A mechanistic model of N 2O emission from agricultural soil (DeNitrification-DeComposition—DNDC) was modified for application to the UK, and was used as the basis of an inventory of N 2O emission from UK agriculture in 1990. UK-specific input data were added to DNDC's database and the ability to simulate daily C and N inputs from grazing animals and applied animal waste was added to the model. The UK version of the model, UK-DNDC, simulated emissions from 18 different crop types on the 3 areally dominant soils in each county. Validation of the model at the field scale showed that predictions matched observations well. Emission factors for the inventory were calculated from estimates of N 2O emission from UK-DNDC, in order to maintain direct comparability with the IPCC approach. These, along with activity data, were included in a transparent spreadsheet format. Using UK-DNDC, the estimate of N 2O-N emission from UK current agricultural practice in 1990 was 50.9 Gg. This total comprised 31.7 Gg from the soil sector, 5.9 Gg from animals and 13.2 Gg from the indirect sector. The range of this estimate (using the range of soil organic C for each soil used) was 30.5–62.5 Gg N. Estimates of emissions in each sector were compared to those calculated using the IPCC default methodology. Emissions from the soil and indirect sectors were smaller with the UK-DNDC approach than with the IPCC methodology, while emissions from the animal sector were larger. The model runs suggested a relatively large emission from agricultural land that was not attributable to current agricultural practices (33.8 Gg in total, 27.4 Gg from the soil sector). This ‘background’ component is partly the result of historical agricultural land use. It is not normally included in inventories of emission, but would increase the total emission of N 2O-N from agricultural land in 1990 to 78.3 Gg.