Germany: The Baltic Sea and its agricultural environmental status

Abstract

The contribution of diffuse (mainly agricultural) nutrient inputs into surface waters and then into the Northern and Baltic Seas has been estimated for nitrogen as approximately 60% and for phosphorus as approximately 47% of the total inputs for Germany (reference year 1989). The most important diffuse pathways are the input via groundwater and drainwater for nitrogen and via soil erosion for phosphorus. In both cases, about two-thirds of the total diffuse inputs are caused by these single sources. Only 8% of the total area of the former Federal Republic of Germany is within the catchment of the Baltic Sea. In using an area-proportional calculation, the absolute nutrient input into the Baltic Sea from agriculture could be estimated as 52.6 kt of nitrogen and 4 kt of phosphorus for 1989. The present situation in Germany indicates some improvements in the environmental status of agriculture as far as the potential for nutrient pollution of surface waters is concerned. The changes of the agricultural structure in the former German Democratic Republic after the reunification resulted particularly in a large scale reduction in livestock density, as well as a large amount of arable land being taken out of production. Therefore, the present situation is characterized by a significant reduction in the supply of farmyard and liquid manure, by reduced application rates of mineral fertilizers and, for land no longer in production, by a lower susceptibility for soil erosion. This reduced pollution potential should also result, with an unknown time-lag, in a lower nutrient input into the surface waters. Furthermore, the dramatic decrease of livestock density by more than 60% within the last 3 years will have a positive impact on the direct nutrient inputs by a careless or even illegal discharge of liquid manure, animal slurries and effluents from stored farmyard manure. It is an important demand that agriculture should increase their efforts to reduce the diffuse nutrient inputs into groundwater and surface water. Consequently, the activity of the official agricultural advisory service is especially focused on water-protection measures. ‘Fertilizer application prescriptions’ within the framework of the German ‘fertilizer regulation’ will limit the fertilizer application and, in particular, the application rates of animal slurry. Furthermore, the future selection of arable land for temporary or permanent removal from production will reinforce the water-protection potential of those measures.