Ammonia and Mineral Losses on Dutch Organic Farms with Pregnant Sows

The main objective of this study was to quantify ammonia emissions from organically raised pregnant sows and to compare them with emissions from conventional pig production. A second objective was to quantify the nutrients deposited in the paddock in organic pig grazing systems. Measurements were carried out on three Dutch farms on 1 day in each of two measuring seasons (spring/summer and autumn). Ammonia emissions were measured by the ventilated chamber technique at different locations inside the building and on the paved outside yard. The nutrient loads of N, P and K were calculated according to their content in urine and faeces, average weight of urine and faeces per excretion, and number of urinations and defecations in the paddock. Ammonia emission per m2 did not differ statistically significantly between seasons and between inside and outside the building. Fouling of the floor with urine and faeces had a strong effect on ammonia emission (probability P