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Adaptive Strategies to Reduce Nutrient Input

An important goal of the focus issue "Water Management and Agriculture” is the development of adaptive strategies for the reduction of nutrient inputs into surface waters. Due to possible climate changes in the region, trends showing an increased utilization of renewable raw materials and possible competition between food and raw material production, one can expect an intensification of agricultural production.

Through the initiation of tile drainage systems in agricultural areas in the last century (which causes a change in agricultural hydrology), the potential for the breakdown of nitrogen in the soil and in groundwater has been substantially limited. Presently, tile drainage is responsible for about 50% of the region’s nitrogen inputs into surface waters. Considering the anticipated increased precipitation in winter and decreased precipitation in summer due to climate change, the tile drainage pathway will dominate the nutrient inputs even more. Therefore it is essential to develop measures and strategies for compensation in order to avoid long-term damage to agricultural production. The recovery of lost nutrient retention potential as well as the creation of new retention potential in the country side are sensible possibilities for reducing nutrient inputs into surface waters. At the moment, the Institute of Landscape Hydrology of ZALF is running experiments to regulate tile drainage water as well as to reduce nitrogen inputs from tile drainage systems by means of retention ponds near the tile drainage outlet.

Through the implementation of another retention pond in the northern part of the German Baltic Coast catchment area, in addition to the already existing examples of successful implementation in the eastern part, RADOST clearly demonstrates the potential of these adaptive strategies for different landscapes. On the basis of the results of these sub-projects, RADOST also advises possible users (farmers, water and soil associations) with regards to selecting locations, dimensioning and the effects of this measure. In addition, other methods of nutrient reduction suitable for the region will be researched by means of an exhaustive study of the existing literature in co-operation with ZALF. The results of this study will be presented to the participating stakeholders in collective meetings in order to widen the range of possible courses of action and to discuss their on-site feasibility.

Contribution to Networking in RADOST

This sub-project contributes to the network structure of RADOST mainly through co-operation with the water and soil associations. Together with these associations, construction details and sampling methods will be discussed, also in co-operation with local farmers, and the final location of the retention ponds will be determined. Furthermore, further suitable measures for nutrient load reduction through tile drainage systems will be discussed, together with these partners, mainly in the form of workshops.

Contribution to Adaption to Climate Change and Sustainability in the Region

One important adaption to climate change is the reduction of nutrient loads into surface waters. Therefore, the dominating pathway of the tile drainages offers a particularly sensible possibility for the short and middle term reduction of nutrient loads.

The tile drainage pathway shows only short retention times of the water in comparison to the groundwater pathway. Therefore, measures for the tile drainage pathway enable a quicker reduction of nutrient loads. Furthermore, these measures are very effective for improving water quality because of high nutrient concentrations in the tile drainage water and due to the low possibility of reducing this concentration through retention until it reaches the surface water.

One possibility for adaption would be the planning and the implementation of these retention ponds in this region. The results for potential reductions from this pilot installation remain to be seen. The calculations of the influences of climate change on water quality as well as the cost-benefit analysis of measures for the nutrient load reduction contribute to the sustainability of the region. The creation of jobs for the planning, construction, frequent sampling and maintenance of the retention ponds (and potentially through other measures, which will be proposed as result of the project work) is possible.

Kontakt
Institution: 
Leibniz-Institute of Freshwater and Inland Fisheries
Straße, Nr.: 
Müggelseedamm 310
PLZ, Ort: 
12587 Berlin
Web: 
http://www.igb-berlin.de
Contact person: 
Kontakt: 
Contact person: 
Dr. Ulrike Hirt
Other staff involved: 
Judith Mahnkopf