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Veröffentlichung Nitrogen soil surface budgets for districts in Germany 1995 to 2017(2020) Häußermann, Uwe; Klement, Laura; Breuer, Lutz; Ullrich, Antje; Wechsung, GabrieleBackground Nitrogen (N) as a key input for crop production has adverse effects on the environment through emissions of reactive nitrogen. Less than 20% of the fertiliser nitrogen applied to agricultural land is actually consumed by humans in meat. Given this situation, nitrogen budgets have been introduced to quantify potential losses into the environment, to raise awareness in nutrient management, and to enforce and monitor nutrient mitigation measures. The surplus of the N soil surface budget has been used for many years for the assessment of potentially water pollution with nitrate from agriculture. Results For the 402 districts in Germany, nitrogen soil surface budgets were calculated for the time series 1995 to 2017. For the first time, biogas production in agriculture and the transfer of manure between districts were included in the budget. Averaged for all districts, the recent N supply to the utilised agricultural area (UAA) totals 227 kg N ha-1 UAA (mean 2015-2017), among them 104 kg N ha-1 UAA mineral fertiliser, 59 kg N ha-1 UAA manure, 33 kg N ha-1 UAA digestate, 14 kg N ha-1 UAA from gross atmospheric deposition, 13 kg N ha-1 UAA biological N fixation, and 1 kg N ha-1 UAA from seed and planting material. The withdrawal with harvested products accounts for 149 kg N ha-1 UAA, resulting in an N soil surface budget surplus of 77 kg N ha-1 UAA. The N surpluses per district (mean 2015-2017) vary considerably between 26 and 162 kg N ha-1 UAA and the nitrogen use efficiency of crop production ranges from 0.53 to 0.79 in the districts. The N surplus in Germany as a whole has remained nearly constant since 1995, but the regional distribution has changed significantly. The N surplus has decreased in the arable farming regions, but increased in the districts with high livestock density. Some of this surplus, however, is relocated to other districts through the transfer of manure. Conclusions The 23-year time series forms a reliable basis for further interpretation of N soil surface surplus in Germany. Agri-environmental programmes such as the limitation of the N surplus through the Fertiliser Ordinance and the promotion of biogas production have a clear effect on the N surplus in Germany as a whole and its regional distribution. © 2020 BioMed Central Ltd.Veröffentlichung National nitrogen budget for Germany(2021) Häußermann, Uwe; Bach, Martin; Fuchs, Stephan; Geupel, MarkusEmissions of reactive nitrogen (Nr) give rise to a wide range of environmental problems. Nitrogen budgets for various systems and on different scales are an established tool to quantify the sources and fate of Nr. The national nitrogen budget (NNB) for Germany calculates the nitrogen flows for eight pools: Atmosphere, Energy and Fuels, Material and Products in Industry, Humans and Settlements, Agriculture, Forest and Semi-natural Vegetation, Waste, and Hydrosphere, as well as for the transboundary N-flows. In Germany, in total 6,275 kt Nr a-1 has been introduced into the nitrogen cycle annually (mean 2010 to 2014), of which 43% stem from ammonia synthesis. Domestic extraction and import of nitrogenous fossil fuels (lignite, coal, crude oil) releases another 2,335 kt Nr a-1. Import of food, feed and materials contributes 745 kt Nr a-1, while biological N fixation converts 308 kt Nr a-1 into organically bound nitrogen. In terms of Nr sinks, the combustion and denoxing of fuels and the refining of crude oil converts 2,594 kt Nr a-1 to N2. In waters, soils, and wastewater treatment plants, denitrification leads to the release of 1,107 kt Nr a-1 as N2. Via the atmosphere and hydrosphere, Germany exports 755 kt Nr a-1 to neighbouring countries and into coastal waters. On balance, Germany releases 1,627 kt Nr a-1 annually to the environment. However, the NNB as a whole and the individual pool balances involve substantial uncertainties, which have to be considered when interpreting the results. ©2021 The Author(s)