The introduction of reactive nitrogen into the environment affects the air and groundwater quality, the good condition of land and marine ecosystems, as well as climate and biodiversity. Reducing nitrogen emissions is therefore a key task of environmental policy. The report shows the relevant sources, sinks and flows of the nitrogen cycle in Germany. A total of around 150 flows of ammonia, nitrogen oxides, nitrous oxide and nitrate between soil, plants, animals, food and feed, industrial products etc. are quantified. Based on that strategies for reducing nitrogen emissions can be developed and the impact of measures can be assessed.