Globally, losses of excess nitrogen (N) from agriculture are affecting our air and water quality. This is a well-known environmental threat and is caused by food production for an ever-growing population. Since the 1980s, many European countries, such as Denmark, have successfully combatted N pollution in the aquatic environment by regulating and introducing national agricultural one-size-fits-all mitigation measures. However, further reduction of the N load is still required to meet the demands of, e.g., the EU water directives. Scientifically and politically, implementing additional targeted N regulation of agriculture is a way forward. A comprehensive Danish groundwater and modelling concept has been developed to produce high-resolution groundwater N retention maps showing the potential for natural denitrification in the subsurface. The concept’s implementation aims to make future targeted N regulation successful environmentally and economically. Quaternary deposits, formed by a wide range of glacial processes and abundant in many parts of the world, often have a very complex geological and geochemical architecture. The results show that the subsurface complexity of these geological settings in selected Danish catchments results in large local differences in groundwater N retention. This indicates a high potential for targeted N regulation at the field scale. A prioritization tool is presented that has been developed for cost-efficient implementation at a national level to select promising areas for targeted N regulation.
Presenter Name
Birgitte
Presenter Surname
Hansen
Area
Denmark
Conference year
2023