Uncertainty analysis of mineral excretion and manure production

Since the beginning of the nineties, standard factors for manure production and nutrient excretion per livestock category have been determined by the Working group on the Uniformisation of the calculation of Manure and minerals figures (WUM).

The results on manure production and mineral excretions are input to other calculations such as calculation of ammonia emissions and greenhouse gas emissions from agriculture. Data on ammonia emissions and greenhouse gas emissions are used by the Netherlands Pollutant Release and Transfer Register (PRTR) in international reports. Within the framework of these reports, assessment of uncertainties is necessary. The Netherlands Pollutant and Transfer Register therefore asked WUM to assess uncertainties in manure production and mineral excretions.