@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}
}
