We need to discuss land use and help farmers to improve the quality of water. In a local newspaper from the 13th of January 2023, this approach was presented by the help of the Landwirtschaftskammer of lower saxony.
The Dümmer lake is mainly filled by the upper river Hunte, which springs in the Wiehengebirge. Rainwater falls over (agricultural) used lands and fills up streams, the upper river Hunte and flows into the lake Dümmer. In the maps below the catchment area of the river and smaller streams is shown. The Wiehengebirge in the south of the Dümmer region has a higher level then the sourrounded wet lands and the lake, which means that the collected water flows into and through the lake.
Agricultural used land like fields not always have plants on it, for example in the winter time or inbetween crops. But plants are highly important, because they cover the ground and the roots stabilize it. When its raining, it can come to erosion in particular in steeper areas. In the Wiehengebirge, the hill range south of the Dümmer, steep areas are also used for agriculture.
The Landwirtschaftskammer of lower saxony, gives advises to farmers to protect water bodies. Raimund Esch works as such water advisor at the Landwirtschaftskammer in Osnabrück and also used to participate at some of the LimnoScenES workshops and working groups at the Dümmer. He also helped to write the policy brief we addressed in October 2022 to lower saxony politicians and ministers.
In the articel by the NOZ he talked about how farmers can work against erosion on fields. For example it can hep to not plow right next to a stream or creek. Another option is to grow other plants inbetween crops. He also talks about the advisory function of the Landwirtschaftskammer. Most of the agriculture measures are non-obligatory by the farmers, but they also get damage payments for such environmentally friendly measures. Also, more and more farmers tend to use agriculture measures to protect surface water.
The problem of erosion ist that not just topsoil is washed away but also biomass, fertilizers and so on, like pictured above. With washed away biomass and fertilizers the nutrient entry rises extremly. The erosion problems lead to more problems, like that the surface water bodies include so much nutrients, that for example algae or Cyanobacteria grows faster. The problem, again, leads to other problems like a high amount of dying fish and bathing ban. In the end, the agriculture in the catchment area influences the Dümmer and its business like tourism. This is why we are happy to hear, that the farmers are willing to go with new techniques to protect the environment.
You find the german articel here: NOZ Artikel