Schatting van stikstofverliezen uit stallen op basis van de stikstof-fosfaat verhouding in afgevoerde mest: Evaluatie van de NP-methode en effect van staltype

This research studied the usability of the ratio of nitrogen to phosphate in manure before and after storage, in order to interpret the difference between N losses from low-emission housing compared to that from the reference housing without low-emission equipment. Airscrubbers were not included in this research. The analysis was performed using national data, in addition for dairy, farm-specific data were used, allowing correction for farm-specific factors. The analyses showed that differences between N losses from low-emission- and reference housing could be well interpreted. The results showed that the studied low-emission housing systems (until 2021) for dairy did not have verifiable lower N losses than the reference A1.100 barn, even after correction for farm-specific characteristics. Low-emission houses for fattening pigs and poultry did show lower N losses than from the reference housing systems, but not as much as might be expected. Further research is needed to get a grip on the factors that reduce the effect of low-emission systems to ensure efficacy.