J.F.M. Huijsmans

Effect of application method, manure characteristics, weather and field conditions on ammonia volatilization from manure applied to arable land

Abstract To predict ammonia (NH3) volatilization from field-applied manure, factors affecting volatilization following manure application need to be known. A database of field measurements in the Netherlands was analysed to identify these factors and to quantify their effects on the volatilization of NH3 from liquid pig manure applied and incorporated on arable land. The combination and the statistical analysis of these data, together with the models that were designed, yielded valuable information about the factors that influence NH3 volatilization, and about the magnitude of their effects when applying and incorporating manure on arable land. Factors analysed were application method, characteristics of the manure, weather and field conditions. The mean total volatilization, expressed as % of the total ammoniacal nitrogen (TAN) applied, was 68% for surface spreading, 17% for surface incorporation and 2% for deep placement. The volatilization rate increased with an increase in TAN content of the manure, manure application rate and air temperature. Wind speed had a substantial effect on the volatilization rate, only when manure was surface applied or surface incorporated. The results show that useful prediction of ammonia volatilization following manure application on arable land in the Netherlands is feasible on the basis of information about application method, characteristics of the manure and weather conditions.

Methodology for estimating emissions from agriculture in the Netherlands. Calculations of CH4, NH3, N2O, NOx, PM10, PM2.5 and CO2 with the National Emission Model for Agriculture (NEMA)

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) are calculated from animal housing, manure storage, manure application and grazing 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.

Emissies naar lucht uit de landbouw in 2016 : Berekeningen met het model NEMA

Agricultural activities are in the Netherlands a major source of ammonia (NH3), nitrogen oxide (NO), nitrous oxide (N2O), methane (CH4) and particulate matter (PM10 and PM2.5). The emissions in 2016 were calculated using the National Emission Model for Agriculture (NEMA). Some figures in the time series 1990-2015 were revised. The method calculates the NH3 emission from livestock manure based on the total ammonia nitrogen (TAN) content in manure. In 2016 NH3 emissions from livestock manure, fertilizer and other sources in agriculture, from hobby farms, private parties and manure disposal in nature areas amounted to 116.8 million kg NH3, 1.3 million kg more than in 2015. Nitrogen excretion increased due to expansion of the dairy herd, but because of a larger share of low emission housing and more manure exports outside agriculture, the increase in NH3 emission remained limited. N2O emissions in 2016 were 21.1 million kg at virtually the same level as in 2015(21.2). NO emissions in 2016 totaled 22.8 million kg compared to 22.6 million kg in 2015. CH4 emissions increased from 496 to512 million kg due to the expansion of the dairy herd. Emissions of particulate matter PM10 and PM2.5, 6.5 and 0.6 million kg respectively, did not change compared to 2015. NH3 emissions from livestock manure in the Netherlands dropped by almost two thirds since 1990, mainly as a result of lower nitrogen excretion rates by livestock and low emission manure application. Emissions of N2O and NO also decreased over the same period, but less strongly (38% and 31% respectively), due to higher emissions from manure injection into the soil and the shift from poultry housing systems with liquid manure towards solid manure systems. CH4 emissions reduced by 13% between 1990 and 2016 caused by a decrease in livestock numbers and increased feed efficiency of dairy cattle.