@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 {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 {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}
}
