Excretieforfaits melkvee : actualisatie 2021

Samenvatting

The Dutch standards for the excretion of nitrogen and phosphorus in manure by dairy cows are listed in Table II of the Implementing Regulation. These standards are updated regularly. During the 2021 update, the calculation method was refined by using milk production specific diets. This refinement was based on a dataset derived from the Dutch Annual Nutrient Cycling Assessment, including data from nearly all dairy farms over the years 2017, 2018 and 2019. Based on this dataset, it was shown that the updated standards for the excretion of nitrogen and phosphorus in manure by dairy cows are in line with the observed excretion of nitrogen and phosphorus in manure by dairy cows producing between 3.000 and 13.000 kg milk per cow per year. The updated standards differ from the current standards, especially for phosphate. Implementation of the new standards in the so-called Phosphate Production Act would increase the room for manure production by the Dutch dairy herd by 3,6 million kg of phosphate and by 13-14 million kg of nitrogen per year.