Graslandmanagement voor reductie van methaan en ammoniak: Jaarrapport 3: 2022 en meerjarenanalyse 2020-2022 : Resultaten van een meerjarige KringloopWijzer-analyse van 12-15 pilotbedrijven

Samenvatting

This project focuses on an integrated approach to reduce methane (CH4) and ammonia (NH3) emission on dairy farms, with changes in grassland management as a measure. For 15 pilot farms with grazing cattle, the current efficiency and corresponding CH4 and NH3 emission was calculated. This was done using the Annual Nutrient Cycle Assessment (ANCA) from 2021, using more detailed input on grassland related to CH4 and NH3 emission and applying adapted emission factors for CH4 (A), while simulating single (B) and combined (C) effects of farm characteristics and management strategies on emission. This overview shows that increasing grazing hours and increasing fresh grass intake can contribute to simultaneous reduction of CH4 and NH3 on dairy farms. The crude protein level of additional roughage feeding plays an important role in reducing NH3 emission. Fresh grass, especially in spring, remains an important management tool. It is expected that CH4 emission can be reduced by 2- 16% on dairy farms with grazing practices through management measures. The comparison of farm characteristics and emission of CH₄ and NH₃ over the years 2020–2022 shows both consistent trends and variations between farms and years. This report describes the analysis and comparison of the results of 15 pilot farms in the dataset of 2020-2022, as an exploratory study. Since the selection of dairy farms used in this study is not representative for the entire sector, the results cannot directly be translated to practice.