Balticsea 2020

Integrated bufferzones

Despite great efforts in the form of advisory services and improved agricultural practices, nutrient runoff from farmland is still the greatest reason for poor environmental health in the Baltic Sea. Another unsolved problem is the hundreds of thousands of drainage pipes in fields around the Baltic Sea, which lead nutrient-rich water straight out into waterways. The “Integrated bufferzones” project is run by the Rural Economy and Agricultural Society of Halland in partnership with Halmstad University in Sweden, as well as the Knowledge Centre for Agriculture and the Institute of Food and Resource Economics in Denmark, and aims to reduce nutrient runoff from fields into the Baltic Sea.

Background
The problem of eutrophication in the Baltic Sea has generated many proposals for solutions, such as changing agricultural practices and the creation of wetlands, but so far there is no way of reducing subterranean nutrient runoff via drainage pipes. Along long stretches of the Baltic coastline there are large numbers of drainage pipes that lead nutrient-rich water from fields into waterways.

Purpose and aim
The purpose of this project is to clean the nutrient-rich water from the fields using “integrated bufferzones”. In principle, these provide comprehensive filtration of both surface water and drainage water, resulting in excellent protection from nutrient runoff from agricultural land into waterways and the sea. The project will perform a scientific evaluation of how much nitrogen and phosphorus can be removed by using the protection zones. The aim is then to spread this innovative technique to more countries around the Baltic Sea.

The project is run by the Rural Economy and Agricultural Society of Halland in partnership with Halmstad University in Sweden and the Knowledge Centre for Agriculture and the Institute of Food and Resource Economics in Denmark, with funding from the BalticSea2020 foundation. The foundation has a history of supporting innovative measures that are assessed as having significant potential to improve the environment of the Baltic Sea, and this project is seen as another opportunity for reducing nutrient runoff from land to our waters.

Issues such as cost-effectiveness, site-specific dimensions and the removal efficiency of nitrogen and phosphorus will be evaluated over a three-year period.

Illustration, integrated bufferzone

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The nutrient-rich water is cleaned using a channel and filtration bank built between the field and the ditch. For the filtration to work optimally, trees are planted on the filtration bank to absorb nutrients from the water. This means that no water moves from the field to the waterway without first having been cleaned from phosphorus and nitrogen, thus reducing eutrophication in nearby waterways.