@article {67,
	title = {Nitrogen balance and mineral nitrogen content in the soil in a long experiment with maize under different systems of N fertilization.},
	journal = {Plant Soil Environment},
	volume = {49},
	year = {2003},
	pages = {554-559},
	abstract = {The effect of different systems of N fertilization on nitrogen balance and N transformation in the soil was studied in
long-term stationary experiments (1991{\textendash}2002) with successive growing of maize. Average dry matter yield for the control
without fertilization in the period 1991{\textendash}2002 was 11.67 t of dry matter per ha, which was by 2{\textendash}2.9 t less than for
fertilization treatments. Statistically significant differences between the control and fertilization treatments were determined
for the first time in the 4th experimental year. Average nitrogen uptake by the aboveground biomass was 116 kg N/ha
for the control, 162{\textendash}170 kg N/ha for fertilization treatments. All experimental treatments had a negative balance of N inputs
and outputs, and it was {\textendash}1394 kg N/ha for the control (for 12 experimental years). After the application of mineral
fertilizers, a lower content of total carbon and nitrogen was measured in the topsoil compared to the control and treatments
with organic fertilization. The changes in the nitrogen regime of soil were characterized by the content of extractable
nitrogen and carbon in extractions by 0.01M CaCl2. With respect to the content of mineral nitrogen and easily
extractable organic nitrogen and carbon in the topsoil the control was most stable followed by farmyard manure treatment.
Soil lysimeters were installed in these experiments (depth 60 cm, size 0.2 m2). For an eight-year period (1994/2002)
11.78 kg N-NO3 {\textendash}/ha were determined in lysimetric waters. These values for fertilization treatments ranged from 21.0 to
58.2 kg N-NO3 {\textendash}/ha. Straw application reduced nitrate contents in lysimetric waters.},
	keywords = {EPNB},
	author = {Balik, J and Cerny, J and Tlustos, P and Zitkova, M}
}
@article {66,
	title = {Reducing nitrogen surplus from dairy farms. Effects of feeding and management.},
	journal = {Livestock Production Science},
	year = {2003},
	pages = {165-178},
	abstract = {The objective of the present paper is to review the factors which can affect N flow and surplus both at farm and at cow
level in order to point out areas with scope for future improvement. Special attention is given to management factors and
feeding. Besides information from the literature the paper is based on meta-analyses of our own and published results. With
regard to effects of production systems, mainly Danish surveys have been chosen as examples demonstrating the effects
obtained under practical conditions. A positive correlation between stocking rate and N surplus per hectare at farm gate level
is demonstrated, but there is also a considerable variation in N surplus per hectare at a given stocking rate. A number of
factors influencing N surplus and loss have been identified, and their impact on N surplus and production efficiency has been
estimated. N excretion per animal is an important factor for N turnover at farm level. Analysis of herd data indicates that
feeding strategy, breed and milk yield, together with energy conversion and the protein content of the diet, are important
factors explaining N excretion and N efficiency of cows. Reduction of N intake by optimal synchronisation of energy and
protein supply over time, especially in pasture-based systems, is one way of reducing N excretion from cows. Furthermore,
the ideal profile of absorbed amino acids should be identified, and models to estimate amino acid supply to the intestine
should be further improved. The effect of reducing N excretion from cows has to be evaluated at farm level as manure is
used as fertiliser for crop production. Overall, it seems possible to reduce the N surplus through better management and
feeding without reducing production efficiency.},
	keywords = {EPNB},
	author = {Borsting, C. F and Kristensen, T and Misciattelli, L and Hvelplund, T and Weisbjerg, M. R}
}
@article {Leip2008a,
	title = {{Linking an economic model for European agriculture with a mechanistic model to estimate nitrogen and carbon losses from arable soils in Europe}},
	journal = {Biogeosciences},
	volume = {5},
	number = {1},
	year = {2008},
	month = {jan},
	pages = {73{\textendash}94},
	abstract = {A comprehensive assessment of policy impact on greenhouse gas (GHG) emissions from agricultural soils re- quires careful consideration of both socio-economic aspects and the environmental heterogeneity of the landscape. We developed a modelling framework that links the large-scale economic model for agriculture CAPRI (Common Agricul- tural Policy Regional Impact assessment) with the biogeo- chemistry model DNDC (DeNitrification DeComposition) to simulate GHG fluxes, carbon stock changes and the nitrogen budget of agricultural soils in Europe. The framework allows the ex-ante simulation of agricultural or agri-environmental policy impacts on a wide range of environmental problems such as climate change (GHG emissions), air pollution and groundwater pollution. Those environmental impacts can be analyzed in the context of economic and social indicators as calculated by the economic model. The methodology con- sists of four steps: (i) definition of appropriate calculation units that can be considered as homogeneous in terms of eco- nomic behaviour and environmental response; (ii) downscal- ing of regional agricultural statistics and farm management information from a CAPRI simulation run into the spatial calculation units; (iii) designing environmental model sce- narios and model runs; and finally (iv) aggregating results for interpretation. We show the first results of the nitrogen bud- get in croplands in fourteen countries of the European Union and discuss possibilities to improve the detailed assessment of nitrogen and carbon fluxes from European arable soils.},
	isbn = {1726-4170},
	issn = {1726-4189},
	doi = {10.5194/bg-5-73-2008},
	url = {http://www.biogeosciences.net/5/73/2008/},
	author = {Leip, Adrian and Marchi, G. and Koeble, R. and Kempen, M. and Britz, Wolfgang and Li, Changsheng}
}
@inbook {Leip2011p,
	title = {{Agri-Environmental Nitrogen Indicators for EU27}},
	booktitle = {Bio-Economic Models applied to Agricultural Systems},
	year = {2011},
	pages = {109{\textendash}123},
	publisher = {Springer Netherlands},
	organization = {Springer Netherlands},
	address = {Dordrecht},
	abstract = {Nitrogen is a key element to ensure modern agriculture{\textquoteright}s output, sustaining global food, feed, fibre and now bio-energy production. But it also accounts also for, or at least contributes to, key environmental problems that challenge the well functioning of today{\textquoteright}s societies (Sutton et al. 2011). One molecule of nitrogen can contribute to one or many environmental problems, including eutrophication, groundwater pollution via leaching and run-off of nitrates and organic nitrogen, climate change via N2O emissions, acidification via ammonia emissions and may affect human health via ozone formation or biodiversity via nitrogen deposition on natural areas. This multiple impact of nitrogen is often referred to as the {\textquotedblleft}nitrogen cascade{\textquotedblright} (Galloway et al. 2003). Accordingly, agri-environmental indicator frameworks typically feature several indicators related to nitrogen such as ammonia emissions, use of nitrogen fertilisers, gross N surplus, nitrates in water or GHG emissions (EEA 2005). Often, however, these indicators are calculated independently from each other based on sometimes contradicting data sources, methodologies or assumptions (see e.g. Grizzetti et al. 2007). This includes also the first overview of the {\textquotedblleft}European Nitrogen Case{\textquotedblright} that was presented by van Egmond et al. (2002) at the second International Nitrogen Conference held in Potomac (USA). Thus, a system that calculates the detailed nitrogen balance and the related indicators for agriculture in Europe on the basis of consistent data sets and advanced methodologies is highly desirable. A closed balance of nitrogen is calculated in the CAPRI (Common Agricultural Policy Regionalized Impact) model, i.e., next to monetary values and product balances, also the nutrient fluxes are in accordance with the law of mass-conservation (Britz et al., 2007). This has been exploited by Leip et al. (2011b) to develop nitrogen budgets for the system boundaries of the soil, land, and the farm. The authors provide for the first time mutually consistent calculations of farm, land and soil N-budgets for all member states of the European Union and quantify the two major indicators, namely the nitrogen use efficiency and the nitrogen surplus for each of the N-budgets. The data showed that the nitrogen surplus increases for the soil {\textless} land {\textless} farm budget, while the nitrogen use efficiency decreases analogically for soil {\textgreater} land {\textgreater} farm budgets. The farm N-budget appeared to be the most relevant one giving a picture of the overall N management of agriculture and is accordingly recommended for integrative studies assessing the {\textquotedblleft}nitrogen footprint{\textquotedblright} of society. Based on the work of Leip et al. (2011b), we propose in this chapter three additional nitrogen indicators focusing even more on the use society in European countries makes of their productive land.},
	keywords = {mypublications},
	isbn = {978-94-007-1901-9},
	doi = {10.1007/978-94-007-1902-6_6},
	url = {http://www.springerlink.com/content/pq4846/{\#}section=954524{\&}page=1{\&}locus=0},
	author = {Leip, Adrian and Weiss, Franz and Britz, Wolfgang},
	editor = {Flichman, Guillermo}
}
@article {Leip2011b,
	title = {{Farm, land, and soil nitrogen budgets for agriculture in Europe calculated with CAPRI}},
	journal = {Environmental Pollution},
	volume = {159},
	number = {11},
	year = {2011},
	pages = {3243{\textendash}3253},
	abstract = {We calculated farm, land, and soil N-budgets for countries in Europe and the EU27 as a whole using the agro-economic model CAPRI. For EU27, N-surplus is 55 kg N ha -1 yr -1 in a soil budget and 65 kg N 2O-N ha -1 yr -1 and 67 kg N ha -1 yr -1 in land and farm budgets, respectively. NUE is 31{\%} for the farm budget, 60{\%} for the land budget and 63{\%} for the soil budget. NS values are mainly related to the excretion (farm budget) and application (soil and land budget) of manure per hectare of total agricultural land. On the other hand, NUE is best explained by the specialization of the agricultural system toward animal production (farm NUE) or the share of imported feedstuff (soil NUE). Total N input, intensive farming, and the specialization to animal production are found to be the main drivers for a high NS and low NUE. {\textcopyright} 2011 Elsevier Ltd. All rights reserved.},
	keywords = {agriculture, Europe, Nitrogen budgets, Nitrogen use efficiency, Nutrient balances},
	issn = {02697491},
	doi = {10.1016/j.envpol.2011.01.040},
	url = {http://dx.doi.org/10.1016/j.envpol.2011.01.040},
	author = {Leip, Adrian and Britz, Wolfgang and Weiss, Franz and De Vries, Wim}
}
@inbook {Leip2011d,
	title = {{Integrating nitrogen fluxes at the European scale}},
	booktitle = {European Nitrogen Assessment},
	year = {2011},
	pages = {345{\textendash}376},
	publisher = {Cambridge University Press},
	organization = {Cambridge University Press},
	chapter = {16},
	address = {Cambridge, UK},
	keywords = {mypublications},
	url = {http://www.nine-esf.org/ENA-Book},
	author = {Leip, Adrian and Achermann, Beat and Billen, Gilles and Bleeker, Albert and Bouwman, Alexander F and De Vries, Wim and Dragosits, Ulli and D{\"o}ring, Ulrike and Fernall, Dave and Geupel, Markus and Heldstab, J{\"u}rg and Johnes, Penny and Le Gall, Anne Christine and Monni, Suvi and Neve{\v c}e{\v r}al, Rostislav and Orlandini, Lorenzo and Prud{\textquoteright}homme, Michel and Reuter, Hannes I and Simpson, David and Seufert, G{\"u}nther and Spranger, Till and Sutton, Mark A. and van Aardenne, John and Vo{\ss}, Maren and Winiwarter, Wilfried},
	editor = {Sutton, Mark and Howard, Clare and Erisman, Jan Willem and Billen, Gilles and Bleeker, Albert and van Grinsven, Hans and Grennfelt, Peringe and Grizzetti, Bruna}
}
@article {Leip2014b,
	title = {{Nitrogen-neutrality: a step towards sustainability}},
	journal = {Environmental Research Letters},
	volume = {9},
	number = {11},
	year = {2014},
	month = {nov},
	pages = {115001},
	publisher = {IOP Publishing},
	keywords = {Footprint, mypublications, nitrogen},
	issn = {1748-9326},
	doi = {10.1088/1748-9326/9/11/115001},
	url = {http://stacks.iop.org/1748-9326/9/i=11/a=115001?key=crossref.e00563c757c6f69d0f81a98a7c54fa9c},
	author = {Leip, Adrian and Leach, Allison M. and Musinguzi, Patrick and Tumwesigye, Trust and Olupot, Giregon and Stephen Tenywa, John and Mudiope, Joseph and Hutton, Olivia and Cordovil, Claudia M.d.S. and Bekunda, Mateete and Galloway, James N.}
}
@article {Leip2015a,
	title = {{Impacts of European livestock production: nitrogen, sulphur, phosphorus and greenhouse gas emissions, land-use, water eutrophication and biodiversity}},
	journal = {Environmental Research Letters},
	volume = {10},
	number = {11},
	year = {2015},
	pages = {115004},
	publisher = {IOP Publishing},
	abstract = {Livestock production systems currently occupy around28{\%}of the land surface of the European Union (equivalent to65{\%}of the agricultural land). Inconjunction with otherhumanactivities, livestock production systems affect water, air and soil quality, global climate and biodiversity, altering the biogeochemical cycles of nitrogen, phosphorus and carbon. Here,we quantify the contribution of European livestock production to these major impacts. For each environmental effect, the contribution of livestock is expressed as shares of the emitted compounds and land used, as compared to the whole agricultural sector. The results show that the livestock sector contributes significantly to agricultural environmental impacts. This contribution is78{\%}for terrestrial biodiversity loss,80{\%}for soil acidification and air pollution (ammoniaand nitrogen oxides emissions),81{\%}for global warming, and73{\%}for water pollution (bothNandP). The agriculture sector itself is one of the major contributors to these environmental impacts, ranging between12{\%}for global warming and59{\%}for Nwater quality impact. Significant progress in mitigating these environmental impacts in Europe will only be possible through a combination of technological measures reducing livestock emissions, improved food choices and reduced food waste of European citizens. Introduction},
	keywords = {air quality, biodiversity loss, Climate Change, coastal eutrophication, European Union, livestock production, soil acidification},
	isbn = {1748-9318},
	issn = {1748-9326},
	doi = {10.1088/1748-9326/10/11/115004},
	url = {http://stacks.iop.org/1748-9326/10/i=11/a=115004?key=crossref.b8ce885804d5c860e008c03ed18e7ab8 https://zenodo.org/record/58514{\#}.WLQb4zsrKXr},
	author = {Leip, Adrian and Billen, Gilles and Garnier, Josette and Grizzetti, Bruna and Lassaletta, Luis and Reis, Stefan and Simpson, David and Sutton, Mark A. and De Vries, Wim and Weiss, Franz and Westhoek, Henk}
}
@article {Hutton2017,
	title = {{Toward a nitrogen footprint calculator for Tanzania}},
	journal = {Environmental Research Letters},
	volume = {12},
	number = {3},
	year = {2017},
	abstract = {{\textcopyright} 2017 IOP Publishing Ltd.We present the first nitrogen footprint model for a developing country: Tanzania. Nitrogen (N) is a crucial element for agriculture and human nutrition, but in excess it can cause serious environmental damage. The Sub-Saharan African nation of Tanzania faces a two-sided nitrogen problem: while there is not enough soil nitrogen to produce adequate food, excess nitrogen that escapes into the environment causes a cascade of ecological and human health problems. To identify, quantify, and contribute to solving these problems, this paper presents a nitrogen footprint tool for Tanzania. This nitrogen footprint tool is a concept originally designed for the United States of America (USA) and other developed countries. It uses personal resource consumption data to calculate a per-capita nitrogen footprint. The Tanzania N footprint tool is a version adapted to reflect the low-input, integrated agricultural system of Tanzania. This is reflected by calculating two sets of virtual N factors to describe N losses during food production: one for fertilized farms and one for unfertilized farms. Soil mining factors are also calculated for the first time to address the amount of N removed from the soil to produce food. The average per-capita nitrogen footprint of Tanzania is 10 kg N yr-1. 88{\%} of this footprint is due to food consumption and production, while only 12{\%} of the footprint is due to energy use. Although 91{\%} of farms in Tanzania are unfertilized, the large contribution of fertilized farms to N losses causes unfertilized farms to make up just 83{\%} of the food production N footprint. In a developing country like Tanzania, the main audiences for the N footprint tool are community leaders, planners, and developers who can impact decision-making and use the calculator to plan positive changes for nitrogen sustainability in the developing world.},
	keywords = {nitrogen, nitrogen footprint, Sub-Saharan Africa, Tanzania},
	issn = {17489326},
	doi = {10.1088/1748-9326/aa5c42},
	author = {Hutton, M.O. and Leach, Allison M. and Leip, Adrian and Galloway, James N. and Bekunda, M. and Sullivan, C. and Lesschen, J.P.}
}
@article {Vanham2019a,
	title = {{Environmental footprint family to address local to planetary sustainability and deliver on the SDGs}},
	journal = {Science of The Total Environment},
	volume = {693},
	number = {June},
	year = {2019},
	month = {jul},
	pages = {133642},
	publisher = {Elsevier B.V},
	abstract = {The number of publications on environmental footprint indicators has been growing rapidly, but with limited efforts to integrate different footprints into a coherent framework. Such integration is important for comprehensive understanding of environmental issues, policy formulation and assessment of trade-offs between different environmental concerns. Here, we systematize published footprint studies and define a family of footprints that can be used for the assessment of environmental sustainability. We identify overlaps between different footprints and analyse how they relate to the nine planetary boundaries and visualize the crucial information they provide for local and planetary sustainability. In addition, we assess how the footprint family delivers on measuring progress towards Sustainable Development Goals (SDGs), considering its ability to quantify environmental pressures along the supply chain and relating them to the water-energy-food-ecosystem (WEFE) nexus and ecosystem services. We argue that the footprint family is a flexible framework where particular members can be included or excluded according to the context or area of concern. Our paper is based upon a recent workshop bringing together global leading experts on existing environmental footprint indicators.},
	keywords = {Environmental footprint, Environmental footprint assessment, Family, Footprint, Footprint family, Planetary boundaries},
	issn = {00489697},
	doi = {10.1016/j.scitotenv.2019.133642},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0048969719335673 https://doi.org/10.1016/j.scitotenv.2019.133642},
	author = {Vanham, Davy and Leip, Adrian and Galli, Alessandro and Kastner, Thomas and Bruckner, Martin and Uwizeye, Aimable and van Dijk, Kimo and Ercin, Ertug and Dalin, Carole and Brand{\~a}o, Miguel and Bastianoni, Simone and Fang, Kai and Leach, Allison M. and Chapagain, Ashok and Van der Velde, Marijn and Sala, Serenella and Pant, Rana and Mancini, Lucia and Monforti-Ferrario, Fabio and Carmona-Garcia, Gema and Marques, Alexandra and Weiss, Franz and Hoekstra, Arjen Y.}
}
@article {AdrianLeip,
	title = {{The value of manure - manure as co-product in life cycle assessment}},
	journal = {Journal of Environmental Management},
	volume = {241},
	number = {March},
	year = {2019},
	month = {jul},
	pages = {293{\textendash}304},
	publisher = {Elsevier},
	keywords = {Allocation, Fertilizer, Life cycle assessment, Livestock supply chains, Manure, Nutrients},
	issn = {03014797},
	doi = {10.1016/j.jenvman.2019.03.059},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0301479719303627},
	author = {Leip, Adrian and Ledgart, Stewart and Uwizeye, Aimable and Palhares, Julio C.P. and Aller, Fernanda and Amon, Barbara and Binder, Michael and Cordovil, Claudia M.d.S. and Dong, Hongming and Fusi, Alessandra and Helin, Janne and H{\"o}rtenhuber, Stefan and Hristov, Alexander N. and Koelsch, Richard and Liu, Chunjiang and Masso, Cargele and Nkongolo, Nsalambi V. and Patra, Amlan K. and Redding, Matthew R. and Rufino, Mariana C. and Sakrabani, Ruben and Thoma, Greg and Vert{\`e}s, Fran{\c c}oise and Wang, Ying and Ledgard, Stewart and Uwizeye, Aimable and Palhares, Julio C.P. and Aller, M. Fernanda and Amon, Barbara and Binder, Michael and Cordovil, Claudia M.d.S. and De Camillis, Camillo and Dong, Hongming and Fusi, Alessandra and Helin, Janne and H{\"o}rtenhuber, Stefan and Hristov, Alexander N. and Koelsch, Richard and Liu, Chunjiang and Masso, Cargele and Nkongolo, Nsalambi V. and Patra, Amlan K. and Redding, Matthew R. and Rufino, Mariana C. and Sakrabani, Ruben and Thoma, Greg and Vert{\`e}s, Fran{\c c}oise and Wang, Ying}
}
@article {Kanter2020,
	title = {{A framework for nitrogen futures in the shared socioeconomic pathways}},
	journal = {Global Environmental Change},
	year = {2020},
	keywords = {corresponding author, s},
	author = {Kanter, David R and Winiwarter, Wilfried and Bodirsky, Benjamin and Bouwman, Lex and Boyer, Elizabeth and Buckle, Simon and Compton, Jana and Dalgaard, Tommy and wim de Vries and Lecl{\`e}re, David and Leip, Adrian and Muller, Christoph and Popp, Alexander and Raghuram, Nandula and Rao, Shilpa and Sutton, Mark A. and Tian, Hanqin and Westhoek, Henk and Zhang, Xin and Zurek, Monika}
}
@article {Kanter2019,
	title = {{Nitrogen pollution policy beyond the farm}},
	journal = {Nature Food},
	volume = {1},
	number = {1},
	year = {2020},
	month = {jan},
	pages = {27{\textendash}32},
	abstract = {Nitrogen is a crucial input to food production and yet its oversupply in many parts of the world contributes to a number of environmental problems. Most policies dedicated to reducing agricultural nitrogen pollution focus on changing farmer behaviour. However, farm-level policies are challenging to implement and farmers are just one of several actors in the agri-food chain. The activities of other actors {\textemdash} from fertilizer manufacturers to wastewater treatment companies {\textemdash} can also impact nitrogen losses at the farm level and beyond. Consequently, policymakers have a broader range of policy options than traditionally thought to address nitrogen pollution from field to fork. Inspired by the concept of full-chain nitrogen use efficiency, this Perspective introduces the major actors common in agri-food chains from a nitrogen standpoint, identifies nitrogen policies that could be targeted towards them and proposes several new criteria to guide ex-ante analysis of the feasibility and design of different policy interventions. Sustainably feeding ten billion people by 2050 will require fundamental changes in the global food system {\textemdash} a broad portfolio of policy options and a framework for how to select them is essential.},
	issn = {2662-1355},
	doi = {10.1038/s43016-019-0001-5},
	url = {https://doi.org/10.1038/s43016-019-0001-5 http://www.nature.com/articles/s43016-019-0001-5},
	author = {Kanter, David R and Bartolini, Fabio and Kugelberg, Susanna and Leip, Adrian and Oenema, Oene and Uwizeye, Aimable}
}
@article {Sanz-cobena,
	title = {{Research meetings must be more sustainable}},
	journal = {Nature Food},
	volume = {1},
	number = {4},
	year = {2020},
	month = {apr},
	pages = {187{\textendash}189},
	issn = {2662-1355},
	doi = {10.1038/s43016-020-0065-2},
	url = {http://www.nature.com/articles/s43016-020-0065-2},
	author = {Sanz-Cobena, Alberto and Alessandrini, Roberta and Bodirsky, Benjamin Leon and Springmann, Marco and Aguilera, Eduardo and Amon, Barbara and Bartolini, Fabio and Geupel, Markus and Grizzetti, Bruna and Kugelberg, Susanna and Latka, Catharina and Liang, Xia and Milford, Anna Birgitte and Musinguzi, Patrick and Ng, Ee Ling and Suter, Helen and Leip, Adrian}
}
@article {Carlo,
	title = {{Sustainable food protein supply reconciling human and ecosystem health: A Leibniz Position}},
	journal = {Global Food Security},
	volume = {25},
	year = {2020},
	month = {jun},
	pages = {100367},
	keywords = {corresponding author, s},
	issn = {22119124},
	doi = {10.1016/j.gfs.2020.100367},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S2211912420300201},
	author = {Weindl, Isabelle and Ost, Mario and Wiedmer, Petra and Schreiner, Monika and Neugart, Susanne and Klopsch, Rebecca and K{\"u}hnhold, Holger and Kloas, Werner and Henkel, Ina M. and Schl{\"u}ter, Oliver and Bu{\ss}ler, Sara and Bellingrath-Kimura, Sonoko D. and Ma, Hua and Grune, Tilman and Rolinski, Susanne and Klaus, Susanne}
}
@article {geupel_national_2021,
	title = {A {National} {Nitrogen} {Target} for {Germany}},
	journal = {Sustainability},
	volume = {13},
	number = {3},
	year = {2021},
	pages = {1121},
	abstract = {The anthropogenic nitrogen cycle is characterized by a high complexity. Different reactive nitrogen species (NH3, NH4+, NO, NO2, NO3-, and N2O) are set free by a large variety of anthropogenic activities and cause numerous negative impacts on the environment. The complex nature of the nitrogen cycle hampers public awareness of the nitrogen problem. To overcome this issue and to enhance the sensitivity for policy action, we developed a new, impact-based integrated national target for nitrogen (INTN) for Germany. It is based on six impact indicators, for which we derived the maximum amount of nitrogen losses allowed in each environmental sector to reach related state indicators on a spatial average for Germany. The resulting target sets a limit of nitrogen emissions in Germany of 1053 Gg N yr-1. It could serve as a similar means on the national level as the planetary boundary for reactive nitrogen or the 1.5 {\textopenbullet}C target of the climate community on the global level. Taking related uncertainties into account, the resulting integrated nitrogen target of 1053 Gg N yr-1 suggests a comprehensible INTN of 1000 Gg N yr-1 for Germany. Compared to the current situation, the overall annual loss of reactive nitrogen in Germany would have to be reduced by approximately one-third.},
	issn = {2071-1050},
	doi = {10.3390/su13031121},
	url = {https://www.mdpi.com/2071-1050/13/3/1121},
	author = {Geupel, Markus and Heldstab, J{\"u}rg and Sch{\"a}ppi, Bettina and Reutimann, Judith and Bach, Martin and H{\"a}u{\ss}ermann, Uwe and Knoll, Lukas and Klement, Laura and Breuer, Lutz}
}
@article {236,
	title = {Nitrogen Opportunities for Agriculture, Food \& Environment: UNECE Guidance Document on Integrated Sustainable Nitrogen Management},
	year = {2022},
	type = {Natalie},
	isbn = {978-1-906698-78-2},
	author = {Mark Sutton and Clare M. Howard and Kate E. Mason and Will Brownlie and Claudia Cordovil}
}
@article {bach_reactive_nodate,
	title = {Reactive nitrogen flows in {Germany} 2010 - 2014 ({DESTINO} {Report} 2)},
	year = {Submitted},
	pages = {152},
	abstract = {Emissions of reactive nitrogen give rise to a wide range of environmental problems. In order to develop reduction measures it is necessary to quantify sources, sinks and flows of Nr, and as part of the Convention on Long-Range Transboundary Air Pollution (CLTRAP) it was agreed in the Gothenburg Protocol to construct national nitrogen budgets. The {\textquotedblleft}Guidance document on national nitrogen budgets{\textquotedblright} of the Economic Commission for Europe forms the starting point for this task. The Nr flows are determined for the following pools: {\textquotedblleft}Atmosphere{\textquotedblright}, {\textquotedblleft}Energy and Fuels{\textquotedblright}, {\textquotedblleft}Material and products in industry{\textquotedblright}, {\textquotedblleft}Humans and settlements{\textquotedblright}, {\textquotedblleft}Agriculture{\textquotedblright}, {\textquotedblleft}Forest and semi-natural vegetation{\textquotedblright}, {\textquotedblleft}Waste{\textquotedblright}, and {\textquotedblleft}Hydrosphere{\textquotedblright}, as well as for the {\textquotedblleft}Trans-boundary N-flows{\textquotedblright} (imports and exports). The N-flows are taken directly from statistical reports, publications, etc., or are calculated as the product of the quantity of transported or converted substance and the mean nitrogen contents. Some 150 N-flows are described, and the uncertainty of the results is graded in four levels from {\textquotedblleft}very low{\textquotedblright} to {\textquotedblleft}high{\textquotedblright}. In Germany, approximately 6275 kt Nr is introduced into the nitrogen cycle every year (mean value from 2010 to 2014), of 43 \% is by ammonia synthesis. Domestic extraction of nitrogenous fossil fuels (lignite, coal, crude oil) and imports contribute 2335 kt N a-1. Natural nitrogen fixation converts 308 kt N a-1 into organically bound nitrogen. Conversely, processes involving the combustion of fossil fuels and regenerative fuels and the refining of crude oil to mineral oil products result in 2711 kt N a-1 being transformed to N2. In waters, soils, and wastewater treatment plants, denitrification leads to the release of 1107 kt N a-1 as molecular nitrogen. Via the atmosphere and hydrosphere, Germany exports 745 kt N a-1 to neighbouring countries and the coastal waters. The changes in N-stock in soils have to date only been determined for forest soils, where they are 293 kt N a-1. On balance, reactive nitrogen totalling 1627 kt N is released in Germany every year, with negative impacts on the ecosystems and their functions. The national nitrogen budget involves considerable uncertainties, and this should be taken into consideration when interpreting the results.},
	author = {Bach, Martin and H{\"a}u{\ss}ermann, Uwe and Klement, Laura and Knoll, Lukas and Breuer, Lutz and Weber, Tatyana and Fuchs, Stefan and Heldstab, J{\"u}rg and Reutimann, Judith}
}
