Agricultural production requires a large quantity of nitrogen. Unfortunately a substantial proportion of the applied nitrogen is lost to the atmosphere in the form of nitrogenous gases including ammonia, nitrogen oxides or nitrous oxide. These trace gases can contribute to the formation of ozone and aerosols, to the greenhouse effect, and to the eutrophication of (semi-) natural ecosystems. ART is therefore studying the emission of nitrogenous trace gases from meadows, depending on the type of management. Our researchers are developing new measurement methods in order to quantify the different trace gas fluxes in long-term field experiments. The results show how much nitrogen is lost to the atmosphere and identify measures by which these emissions can be reduced.