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

Summary

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.