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| Titel |
Farm nitrogen balances in six European landscapes as an indicator for nitrogen losses and basis for improved management |
| VerfasserIn |
T. Dalgaard, J. F. Bienkowski, A. Bleeker, U. Dragosits, J. L. Drouet, P. Durand, A. Frumau, N. J. Hutchings, A. Kędziora, V. Magliulo, J. E. Olesen, M. R. Theobald, O. Maury, N. Akkal, P. Cellier |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 9, no. 12 ; Nr. 9, no. 12 (2012-12-20), S.5303-5321 |
| Datensatznummer |
250007472
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| Publikation (Nr.) |
 copernicus.org/bg-9-5303-2012.pdf |
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| Zusammenfassung |
Improved management of nitrogen (N) in agriculture is necessary to achieve a
sustainable balance between the production of food and other biomass, and
the unwanted effects of N on water pollution, greenhouse gas emissions,
biodiversity deterioration and human health. To analyse farm N-losses and
the complex interactions within farming systems, efficient methods for
identifying emissions hotspots and evaluating mitigation measures are
therefore needed. The present paper aims to fill this gap at the farm and
landscape scales. Six agricultural landscapes in Poland (PL), the
Netherlands (NL), France (FR), Italy (IT), Scotland (UK) and Denmark (DK)
were studied, and a common method was developed for undertaking farm
inventories and the derivation of farm N balances, N surpluses and for
evaluating uncertainty for the 222 farms and 11 440 ha of farmland included
in the study.
In all landscapes, a large variation in the farm N surplus was found, and
thereby a large potential for reductions. The highest average N surpluses
were found in the most livestock-intensive landscapes of IT, FR, and NL; on
average 202 ± 28, 179 ± 63 and 178 ± 20 kg N ha−1 yr−1,
respectively. All landscapes showed hotspots, especially from livestock
farms, including a special UK case with large-scale landless poultry
farming. Overall, the average N surplus from the land-based UK farms
dominated by extensive sheep and cattle grazing was only 31 ± 10 kg N
ha−1 yr−1, but was similar to the N surplus of PL and DK (122 ± 20
and 146 ± 55 kg N ha−1 yr−1, respectively) when landless
poultry farming was included.
We found farm N balances to be a useful indicator for N losses and the
potential for improving N management. Significant correlations to N surplus
were found, both with ammonia air concentrations and nitrate concentrations
in soils and groundwater, measured during the period of N management data
collection in the landscapes from 2007–2009. This indicates that farm N
surpluses may be used as an independent dataset for validation of measured
and modelled N emissions in agricultural landscapes. No significant
correlation was found with N measured in surface waters, probably because of
spatial and temporal variations in groundwater buffering and biogeochemical
reactions affecting N flows from farm to surface waters.
A case study of the development in N surplus from the landscape in DK from
1998–2008 showed a 22% reduction related to measures targeted at N
emissions from livestock farms. Based on the large differences in N surplus between
average N management farms and the most modern and N-efficient farms, it was
concluded that additional N-surplus reductions of 25–50%, as compared to
the present level, were realistic in all landscapes. The implemented
N-surplus method was thus effective for comparing and synthesizing results
on farm N emissions and the potentials of mitigation options. It is
recommended for use in combination with other methods for the assessment of
landscape N emissions and farm N efficiency, including more detailed N
source and N sink hotspot mapping, measurements and modelling. |
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