Farm nitrogen balances in six European agricultural landscapes: a method for farming system assessment, emission hotspot identification, and mitigation measure evaluation
Dalgaard, T.; Bienkowski, J.F.; Bleeker, A.; Drouet, J.L.; Durand, P.; Dragosits, U.; Frumau , A.; Hutchings, N.J.; Kedziora, A.; Magliulo, V.; Olesen, J.E.; Theobald, M.R.; Maury, O.; Akkal, N.; Cellier, P.. 2012 Farm nitrogen balances in six European agricultural landscapes: a method for farming system assessment, emission hotspot identification, and mitigation measure evaluation. Biogeosciences Discussions, 9 (7). 8859-8904. 10.5194/bgd-9-8859-2012Full text not available from this repository.
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 nitrogen (N) balances and N surplus from the in total 222 farms and 11 440 ha of farmland. 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−1yr−1, respectively. However, all landscapes showed hotspots, especially from livestock farms, including a special UK case with landless large-scale poultry farming. So, whereas the average N surplus from the land-based UK farms dominated by extensive sheep grazing was only 31 ± 10 kg N ha−1yr−1, the landscape average was similar to those of PL and DK (122 ± 20 and 146 ± 55 kg N ha−1yr−1, respectively) when landless poultry were included. However, the challenge remains how to account for indirect N surpluses and emissions from such farms with a large export of manure out of the landscape. We conclude that farm N balances are 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 levels in soils and groundwater, measured during the landscape data collection campaign 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. However, no significant correlation was found to N measured in surface waters, probably because of the short time horizon of the study. A case study of the development in N surplus from the landscape in DK from 1998–2008 showed a 22 % reduction, related to statistically significant effects (p < 0.01) of measures targeted at reducing N emissions from livestock farms. Based on the large differences between the average and the most modern and N-efficient farms, it was concluded that 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 at comparing and synthesizing results on farm N emissions and the potentials of mitigation options, and is recommended for use in combination with other methods for the assessment of landscape N emissions and farm N efficiency, including more detailed N sink and N source hotspot mapping, measurements and modelling.
|Item Type:||Publication - Article|
|Digital Object Identifier (DOI):||10.5194/bgd-9-8859-2012|
|Programmes:||CEH Topics & Objectives 2009 onwards > Biogeochemistry|
|Additional Information. Not used in RCUK Gateway to Research.:||Open Access paper - click on Official URL link for full text|
|NORA Subject Terms:||Ecology and Environment
Agriculture and Soil Science
|Date made live:||22 Oct 2012 10:42|
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