Reduction of ammonia emissions in fattening pig houses through the application of a urease inhibitor using different application techniques

Investigations into the use of urease inhibitors for reducing ammonia emission in dairy farming have been published in several papers. The aim of this study is to expand the existing knowledge on the use of urease inhibitors for reducing ammonia emissions in fattening pig houses. In this respect, in addition to the proven standard application approach using a backpack sprayer, the investigation was extended to include different application techniques. Urease inhibitor was applied on two farms over six experimental periods throughout the year using three different application techniques: a backpack sprayer, and a semi-automatic system that applies the inhibitor both on-floor and under-floor. Two identical compartments, alternated between treatment and control, were used on each farm. A linear mixed model with repeated measurements was used to quantify the reduction effect of the urease inhibitor. The use of the backpack sprayer led to a reduction in ammonia emissions of 22.9% (standard error, SE: 4.9%). The on-floor application system reduced the emissions by 16.6% (SE: 4.9%), and the under-floor application system resulted in no significant reduction. The development of the semi-automatic application system can be considered beneficial for reducing emissions. However, further development and improvement of this application system is necessary for its widespread practical use, especially regarding the distribution accuracy of the application liquid, contamination issues, and the manual workload. In addition, the effects of the presence of the animals during the application process need to be investigated in more detail.