Project description

Nitrogen is naturally removed in the subsurface

When the farmer grows his crops, more nitrogen is applied than the plants can absorb to obtain high crop yields. The surplus of nitrogen can be leached from the root zone in the fields and can end in the aquatic environment.

However, on its way through the subsurface, part of the nitrogen is naturally removed by biogeochemical processes. Depending on the geochemical composition and the pathways of the water in the subsurface, larger or smaller parts of the nitrogen are actually removed and thus do not end up in our aquatic environment.

Development of a mapping concept

The project will develop geophysical, hydrogeological and geochemical mapping technologies and a comprehensive concept for mapping the subsurface. The concept can be used to determine the ability of the subsurface under a single field to remove nitrogen so that it does not end up in the aquatic environment .

The project will utilise promising results from the Innovation Fund project rOPEN and other relevant projects.Likewise, the project will create synergy with the Danish National Environmental Monitoring Program, as several of the agricultural monitoring areas will be investigated. We use the long time series of water quality data to validate the methods in MapField. In addition, there is synergy with a number of other projects developing mitigation measures to reduce nitrogen in the aquatic environment. Here we will demonstrate that the MapField methods can be used to select and place instruments optimally in landscape as catch crops, mini wetlands etc.

three sliced earths and a DK mapp

The figure shows: (a) The situation before MapField with uniform N regulation in each ID15 catchment. An ID15 catchment is approx. 15 km2 and is the current level of regulation, (b) Geophysical mapping of the geological structures from an ATV vehicle and drilling of wells for detailed studies of geological and geochemical characteristics, (c) MapField modelling of water and N flow taking the redox conditions. The result is the designation of fields with different needs for N regulation due to different degrees of N retention. N-retention is a measure for how much the subsurface under the individual field can reduce nitrogen and avoid pollution of the aquatic environment, and (d) DK map of the ID15 catchment areas and the study areas.

A highly interdisciplinary project

The combination of knowledge from different scientific disciplines makes the project particularly strong in the development and implementation of a comprehensive mapping concept for targeted nitrogen regulation of agriculture. The project thus combines expertise within both geophysics, hydrogeology, geochemistry, agronomy, modelling, software development, communication, economics and business development.

The project's contribution to society

The project forms the scientific basis for the introduction of the politically decided, more targeted regulation of nitrogen in agriculture. The results of the project will benefit both the farmer and the environment.

The farmer will know where the fertilizer should be used on the field to obtain optimal crop yields in a cost-efficient way. At the same time, the authorities can identify agricultural fields with high or low risk of polluting the aquatic environment thus forming the basis for targeted nitrogen regulation.

MapField can help ensure that Denmark can meet the demands of the EU directives for the aquatic environment, while at the same time creating better production conditions for agriculture.