Nitrogen enrichment of European inland and marine waters with special attention to Danish policy measures

High concentrations of nitrate in groundwater and surface water make it unsuitable as drinking water. Furthermore, high nitrogen emissions to the marine environment cause eutrophication with increased algal growth, changes in the biological communities and deoxygenation. Both groundwater protection and eutrophication are significant environmental issues on the European agenda. The main source of nitrogen in Europe is agricultural leaching from fields caused by excess inputs of fertilisers and manure compared to harvested output. This is especially evident in North-western Europe. It is reflected in river concentrations of nitrate, which are significantly highest in Western Europe. Since the late 1970s, nitrate concentrations have increased all over Europe reflecting intensification of agriculture. High concentrations occur in groundwater in most parts of Europe and most coastal areas of Europe show signs of eutrophication. In Denmark the Parliament in 1987 decided on the Action Plan on the Aquatic Environment (I), which included measures in several sectors. For agriculture the target was a 49% reduction of nitrogen emissions in order to improve groundwater quality and reduce marine loading. In the early 1990s monitoring results and modelling documented that the measures taken in 1987 as well as additional measures taken were insufficient to reach the target. In late 1997 Action Plan on the Environment (II) was agreed maintaining the target, which shall be reached by a range of measures including restoration of wetlands, afforestation, groundwater protection areas, improved animal fodder utilisation, more stringent requirements on livestock density (harmony criteria), more stringent nitrogen utilisation requirements for animal manure, and reduced nitrogen standards for crops. At the European level, the Nitrates Directive has as objective to reduce nitrate emissions to groundwater and surface water. The fact that no country yet has implemented the Directive, clearly documents the difficulties in taking efficient environmental measures in agriculture. The recent Danish policy measures show that there is no easy and cheap solution, which is also politically acceptable. Therefore a wide range of measures are needed to reduce a significant European environmental problem.