The National Emission Model for Agriculture (NEMA) is used to calculate emissions to air from agricultural activities in the Netherlands on a national scale. Emissions of ammonia (NH3) and other N-compounds (NOx and N2O) from animal housing, manure storage, manure application and grazing are assessed using a Total Ammoniacal Nitrogen (TAN) flow model. Furthermore, emissions from application of inorganic N-fertilizer, compost and sewage sludge, cultivation of organic soils, crop residues, and ripening of crops are calculated.NEMA is also used to estimate emissions of methane (CH4) from enteric fermentation and manure management, particulate matter (PM) from manure management and agricultural soils, and carbon dioxide (CO2) from liming. Emissions are calculated in accordance with international guidance criteria and reported in an annual Informative Inventory Report (IIR; for air pollutants) and National Inventory Report (NIR; for greenhouse gases). This methodology report describes the outline and backgrounds of the emission calculations with NEMA. Methodology for estimating emissions from agriculture in the Netherlands | 11
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SummaryThe National Emission Model for Agriculture (NEMA) is used to estimate emissions to air from agricultural activities in the Netherlands. Calculations include the emission of ammonia (NH3), nitrogen oxides (NOx), nitrous oxide (N2O), methane (CH4), particulate matter (PM10, PM2.5) and carbon dioxide (CO2). These emissions originate from various processes within the agricultural production chain, grouped in the Common Reporting Format (CRF; greenhouse gases) and Nomenclature For Reporting (NFR; air pollutants) main categories 3A Enteric fermentation, 3B Manure management, 3DAgricultural soils and 3G Liming.
Enteric fermentationDuring the digestion of feed, ruminal and/or intestinal fermentation processes take place. Especially in cattle, considerable amounts of CH4 are formed. In accordance to the key source analysis, a countryspecific (IPCC Tier 3) method is used for dairy cattle which models the enteric fermentation processes.
Manure managementThis category includes emissions from manure stored inside animal houses, and in outside manure storage facilities. 12 | WOt-technical report 53
Agricultural soilsAs part of the TAN flow, manure N available for application is calculated by subtracting N losses from animal houses and outside manure storages from the total N excretion by livestock. Besides emissions as NH3-N, N2O-N and NOx-N, these losses include N2-N (dinitrogen-N), the use of manure N outside agriculture and (net) export of manure N. The resulting application of livestock manure N is then divided over grassland and cropland (cropped and uncropped), with a differentiation between manure application techniques and their respective NH3 emission factors. For grazed grasslands, NH3 emission is calculated based on TAN excretion on pasture land and an emission factor depending on the N content of the ration. The NH3 emissions from application of inorganic N-fertilizer, sewage s...