- The five-year average of nitrogen surplus of the total balance per hectare of utilized agricultural land has decreased by 34 % since 1992.
- The Federal Government aims to reduce the average nitrogen surplus of the total balance of the years 2028 to 2032 to 70 kilogrammes per hectare of agricultural land.
- If the trend of the last 10 years continues, the target will be reached.
Nitrogen is an essential nutrient for all living organisms. However, excessive input of reactive nitrogen compounds to the environment has serious effects on the climate, biodiversity and landscape quality. For example, nitrogen which is not utilized by plants or is converted back into atmospheric nitrogen may lead to pollution of the groundwater, nutrient enrichment (eutrophication) of waterbodies, acidification of terrestrial ecosystems and the formation of greenhouse gases. An introduction to the issue of nitrogen surplus is given in the publication ’Reactive nitrogen in Germany‘ (UBA 2015) and in the UBA-Umweltatlas "Reaktiver Stickstoff" (in German only).
In Germany problems occur especially in regions with high livestock density: Due to the high amount of farm manure (animal excrements), often more nitrogen is applied to the fields as the crops can convert into biomass. The nitrogen surplus is an indicator of the potential nitrogen losses from agriculture to the environment.
Between 1992 and 2020, the 5-year average nitrogen surplus of the total balance per hectare of agricultural land decreased by around 34 %. Farmers are using nitrogen more efficiently, the area of cultivation of high-output crops has increased and feed conversion by domestic animals has improved.
In recent years, the implementation of more effective agricultural fertilisation legislation, a reduction in animal numbers, years of drought and higher prices as well as lower sales figures for mineral fertilisers have also had an impact. If the trend of the last 10 years were to continue in this way, the goal of the sustainability strategy to reduce the nitrogen surplus to 70 kg N/ha*a in a moving 5-year average by 2030 would be achieved.
But the nitrogen balance also shows: almost half of the nitrogen used does not end up in the products, so nitrogen efficiency is still relatively low (BMEL 2024, Statistischer Monatsbericht, MBT-0111260-000, in German only). The need for further action to reduce nitrogen in the environment is also shown by the indicators " Nitrate in groundwater" and "Nitrogen eutrophication", which are closely linked to the nitrogen surplus and do not indicate any positive trends.
The nitrogen surplus is determined from the total agricultural nitrogen balance. It is the difference between the input (e.g. fertiliser, feed, seed and seedlings, atmospheric inputs) and the output (animal and plant products) of the national farm-gate balance. The data are calculated by the Julius-Kühn-Institute and the University of Gießen and are published annually by the BMEL ((BMEL 2024, Statistischer Monatsbericht, MBT-0111260-000, in German only). Hints to the calculation method can be found in Bach et al. 2011 (in German only) and Häußermann et al. 2019 (in German only). In order to adjust for annual fluctuations a five-year moving average is calculated.
More detailed information: 'Stickstoffeintrag aus der Landwirtschaft und Stickstoffüberschuss' (in German only).
