What does the survey comprise?
Calculation of the level of manure production and minerals excretion by Dutch livestock.
Produced manure and nutrients by livestock category.
Manure types (solid, slurry) and nutrients (nitrogen, phosphate and potassium).
Year survey started
Provisional figures are available at the end of the reporting year. Final data are available 6 months after the end of the reporting year. The results are published in four StatLine tables.
How is the survey conducted?
Calculation on the basis of livestock numbers in the agricultural census and factors for the level of manure production and nutrient excretion per animal per year for a variety of livestock categories.
The production factors per animal per year are multiplied by the number of animals for each animal category in the agricultural census. The Working group on standardization of data on manure and minerals (WUM) sets the factors for manure production and nutrient excretion per livestock category. Statistics Netherlands is part of this working group, together with other stakeholders such as the Ministry of Economic Affairs, LEI-Wageningen UR, Netherlands Environmental Assessment Agency (PBL), National Institute for Public health and the Environment (RIVM) and the Animal Sciences Group - Wageningen UR.
Quality of the results
The 95-percent confidence interval is approximately plus or minus 4 percent.
In general it can be stated that the sequential comparability is good, as the method of calculation has been systematically carried out in the same way every year. In order to obtain a consistent time series, the complete time series is (re)calculated when scientific research gives rise to new insights.
Plausibility control takes place on the basis of trend analysis and monitoring information from the agricultural practice.