Strategies to minimise nutrient leaching from drained agricultural land

 

Lpicturearge areas of arable land in Germany are artificially drained. This applies particularly to peatlands of the North German Plain, but also numerous waterlogged mineral soils. Because of the reduced water flow paths drained sites contribute significantly to nutrient leaching, even if all rules of good agricultural practice are respected. For Schleswig-Holstein it is estimated that between 40 and 60% of nitrogen inputs and 5 to 23% of the phosphorus inputs are emitted via drains into surface waters (UBA 2008). The development and testing of management strategies to reduce the nutrient leaching from drained, agricultural land is therefore an efficient approach to reduce environmental pollution arising from agricultural land use.

pictureAgainst this background, the Deutsche Bundesstiftung Umwelt (DBU) has funded a project that collected measures to reduce nutrient leaching from drained agricultural land together with practice players from Schleswig-Holstein. The result of the project is a regionalised measures catalog that assesses the effectiveness of measures in the main three natural areas in Schleswig-Holstein, estimates the amount of nutrient reduction and gives information about the costs. There were 26 agricultural and 10 other measures selected and published in a practical guide that can be downloaded as pdf in Annex 1 from this page. The agricultural measures may be implemented by the land owners themselves; the other measures increase nutrient retention in the adjacent water bodies outside of the agricultural land.

To depicturetermine the effectiveness of the measures initially literature has been evaluated. The results of the literature research can be found in Annex 2. For determining the amount of nutrient leaching from the drained land under different management strategies the process-based water and nutrient balance model WASMOD from the Company DigSyLand was used. The modeling results were compared with literature data. Besides the level of nutrient reduction, the costs of implementing the various measures have been identified by DUENE eV The detailed description of the procedure can be found in Annex 3.
To determine the risk of nutrient leaching from agricultural land and select appropriate measures for reduction, the practical guide contains an identification key. This key is provided in an interactive version for users on the online portal of the Agricultural Chambers (ISIP) under www.naehrstoffaustrag.isip.info. Here is the publication is also available as a pdf-file.

Zwei Studenten und eine Tasse KaffeeProject period: 1.8.2009 – 31.1.2012
Project leader: Dr. Michael Trepel
Scientific editing: Dr. Bettina Holsten
Cooperation partners: DigSyLand, DUENE e. V., ISIP
Project funding: Deutsche Bundesstiftung Umwelt




On behalf of Baltic Compass extlink the practical guide has been translated into English and adapted to the conditions in the Baltic Sea region. The pdf of the translation can be downloaded here as Annex 5 or from the pages of Baltic Compass.


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