Gestandaardiseerde berekeningsmethode voor dierlijke mest en mineralen : standaardcijfers 1990-2008

Vanaf het begin van de jaren negentig stelt de Werkgroep Uniformering berekening Mesten mineralencijfers (WUM) jaarlijks standaardfactoren vast voor de mestproductie en mineralenuitscheiding per diercategorie. Dit rapport geeft een overzicht van de rekenmethodiek en de uitgangspunten die door de werkgroep zijn toegepast. In 2009 is op verzoek van de Emissieregistratie een herberekening uitgevoerd voor de periode 1990–2006. In de herberekening zijn zoveel mogelijk nieuwe inzichten en tevens een aantal correcties verwerkt. In het voorliggende rapport worden alleen de actuele uitgangspunten voor de periode 1990 tot heden beschreven

A model of enteric fermentation in dairy cows to estimate methane emission for the Dutch National Inventory Report using the IPCC Tier 3 approach

The protocol for the National Inventory of agricultural greenhouse gas emissions in The Netherlands includes a dynamic and mechanistic model of animal digestion and fermentation as an Intergovernmental Panel on Climate Change (IPCC) Tier 3 approach to estimate enteric CH4 emission by dairy cows. The model differs from an IPCC Tier 2 approach in that it predicts hydrogen sources (i.e., production of acetate and butyrate, microbial growth on amino acids as an N source) and sinks (i.e., production of propionate and the remainder of the volatile fatty acids (VFA), microbial growth on ammonia as an N source, saturation of unsaturated long chain fatty acids) in the rumen and large intestine, and elimination of excess hydrogen by methanogenesis. As a result, the model predicts CH4 emission by considering various dietary characteristics, including the types of carbohydrate, protein, fat, intrinsic degradation characteristics of feeds, as well as ruminal fractional passage rates, fluid volume and acidity, instead of assuming a fixed CH4 energy conversion factor in the Tier 2 approach. Annual statistics of diet and performance of the average dairy cow in The Netherlands from 1990 until 2008 indicate that dry matter intake and yield of fat and crude protein corrected milk (FPCM) per cow/year increased by 20 and 34% respectively. Based on annual data for diet and FPCM, the model predicted an increase in enteric CH4 emission from 111 (1990) to 128 (2008) kg/cow/year. As a result, CH4 emission per kg FPCM milk decreased by 13%. The predicted fraction of gross energy intake lost as CH4 energy gradually declined and was close to 0.06, which is the IPCC (1997) Tier 2 default value of 0.06 for dairy cows, but ~10% lower than the IPCC (2006) updated value of 0.065. The 15% uncertainty value for predicted CH4 emissions for a reference diet was lower than the 20% assumed under Tier 2. Our analysis indicated that uncertainty of model predictions of CH4 emission is determined mostly by errors in feed intake estimation, in the representation of the stoichiometry of production of VFA from fermented substrate, and in the acidity of rumen contents. Further uncertainty of predicted CH4 emission was due to errors in estimation of dietary composition of ingredients and in chemical compositions of dietary components. Results demonstrate that prediction of CH4 should not solely focus on representing effects of nutrition on overall digestion and apparent feed utilization by cows, but that additional attention is needed to address effects of nutrition on intra-ruminal fermentation conditions, and their effects on formation of VFA and the rumen hydrogen balance

Gestandaardiseerde berekeningsmethode voor dierlijke mest en mineralen : standaardcijfers 1990-2008

Vanaf het begin van de jaren negentig stelt de Werkgroep Uniformering berekening Mesten mineralencijfers (WUM) jaarlijks standaardfactoren vast voor de mestproductie en mineralenuitscheiding per diercategorie. Dit rapport geeft een overzicht van de rekenmethodiek en de uitgangspunten die door de werkgroep zijn toegepast. In 2009 is op verzoek van de Emissieregistratie een herberekening uitgevoerd voor de periode 1990–2006. In de herberekening zijn zoveel mogelijk nieuwe inzichten en tevens een aantal correcties verwerkt. In het voorliggende rapport worden alleen de actuele uitgangspunten voor de periode 1990 tot heden beschreven

Assessment of the relation between climate and nitrogen related policy for the Dutch situation

Het programma Wetenschappelijke Assessment en Beleidsanalyse Klimaatverandering in opdracht van het ministerie van VROM heeft tot doel: 1) Het bijeenbrengen en evalueren van relevante wetenschappelijke informatie ten behoeve van beleidsontwikkeling en besluitvorming op het terrein van klimaatverandering; 2) Het analyseren van voornemens en besluiten in het kader van de internationale klimaatonderhandelingen op hun consequenties. De analyses en assessments beogen een gebalanceerde beoordeling te geven van de stand van de kennis ten behoeve van de onderbouwing van beleidsmatige keuzes

Emissies naar lucht uit de landbouw berekend met NEMA voor 1990-2020

In the Netherlands, agricultural activities are a major source of gaseous emissions of ammonia (NH3 ), nitrogenoxide (NO), nitrous oxide (N2O), methane (CH4 ), non-methane volatile organic compounds (NMVOC), carbon dioxide(CO 2 ) from lime fertilisers and urea fertiliser, and particulate matter (PM10 and PM2.5 ). These emissions were calculated using the National Emission Model for Agriculture (NEMA). In 2020, NH3 emissions from livestock manure, fertiliser and other sources on farms and hobby farms, from private use and from manure application in terrestrial ecosystems amounted to 113.4 million kg NH3 . This is 0.6 million kg higher than in 2019. Nitrogen excretion from livestock in 2020 was almost the same as in 2019. Emissions of N2 O in 2020 were 19.1 million kg, equal to the level in 2019. Emissions of NO increased by 0.2 million kg in 2020 to 22.3 million kg. Emissions of CH4 decreased slightly from 479 to 477 million kg. Emissions of NMVOC also decreased slightly, from 87.8 to87.6 million kg. Emissions of particulate matter PM10 decreased from 5.5 in 2019 to 5.4 million kg in 2020 and PM 2.5 emissions remained at 0.5 million kg. Emissions of CO2 from lime fertilisers and urea decreased from 85.2 to78.2 million kg. Based on new data for several factors described in this report, emission figures were updated for a number of years in the time series. Emissions of NH3 from livestock manure have decreased by two-thirds since1990, mainly as a result of lower nitrogen excretion rates and the introduction of low-emission manure application. Emissions of N2O and NO also decreased over the same period, but less markedly than the NH3 reduction, by 41% and 33% respectively. Manure injection led to an increase in these emissions compared with surface spreading of manure, while the shift from grazing to housing led to a reduction in these emissions. Emissions of CH4 decreasedby 19% between 1990 and 2020 due to a decrease in livestock numbers and increased feed use efficiency of dairy cattle. Emissions of PM10 increased by 12% in the same period due to laying poultry farms switching from housing systems with slurry manure to systems with solid manure