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Nitrogen application in grass-clover and grass seed needs the right balance

New technology will help farmers maintain the balance between too much and too little nitrogen in grass-clover and grass seed fields to the benefit of the crops and the environment.

[Translate to English:] Den rigtige mængde kvælstof er med til at sikre den optimale græsmark. Foto: Colourbox

Within the framework of a new project coordinated by Aarhus University, scientists aim to develop methods to ensure that the exact amount of nitrogen is applied to fields of grass-clover and grass seed to the benefit of crops and the environment as well as the farmer’s bottom line. 

Nitrate leaching from arable fields contributes to the pollution of the aquatic environment. No one wants this to happen. 

- Nitrate leaching from fields is one of the main culprits in terms of groundwater and sea pollution. The pollution arises when fertilisers are not fully utilised by the crops and therefore end up in the aquatic environment instead, says Professor Jørgen Eriksen, Department of Agroecology at Aarhus University, who is in charge of the new project. 

Various players are therefore making great efforts to minimise leaching. One of the measures is a more targeted and accurate application of nitrogen. 

Accurate nitrogen fertilisation of grass seed fields optimises seed production, while precise nitrogen dosage to grass-clover fields can ensure an optimum combination of clover and grass, which will improve the nutrient value of the mix for animal feed and reduce the risk of nitrogen leaching to the environment. 

Technology to evaluate fertiliser need

With a grant of 15 million DKK from Innovation Fund Denmark, the new four-year project will implement advanced technology. The project will develop camera technology in order to determine the clover/grass ratio in fields as well as map yield potential and nitrogen status in grass seed with the purpose of improving knowledge on the exact fertilising requirements. This knowledge will be translated into fertiliser allocation maps. 

- The results will lead to improved understanding of how nitrogen allocation can optimise yield in grass seed and grass-clover production as well as reduce the environmental impact, says Jørgen Eriksen. 

The project results will be put to practice. The project partners will develop a fertiliser spreader that can apply the exact amount of nitrogen fertiliser. They will also lay the groundwork for a grass-clover module for use in the decision support system MarkOnline, which helps the farmers plan how and when to fertilise their fields with commercial fertiliser and manure. 

Furthermore, the results will be used to document the effect of the applied fertiliser strategies in grass-clover on nitrate leaching with a view to ensuring that grass fields can be used as a measure for targeted regulation of nutrient application. 

Facts on the SmartGrass project 

  • The project name is SmartGrass – Targeted fertilisation of grass-clover and grass seed production through implementation of new sensor technology
  • The four-year project will begin in 2017.
  • Innovation Fund Denmark has granted the project 15 million DKK.
  • The total project budget is 27 million DKK.
  • The Department of Agroecology, Aarhus University, is in charge of the project.
  • Other project partners include AgroIntelli, Seges, DLF, DSV Seed Denmark and I-GIS   

Did you know that ...? 

  • Grassland constitutes 20 percent of Denmark’s agricultural area.
  • Grass-clover is an important feed crop.
  • Denmark is the world’s major grass seed exporter.
  • Nitrate is an important nutrient for crops, but also for aquatic plants. Too much plant growth in the aquatic environment can result in eutrophication and animal death in streams and lakes.

Read also: Nitrogen, clover, camera and image analysis all come together

For more information please contact:

Professor Jørgen Eriksen Department of Agroecology, e-mail: jorgen.eriksen@agro.au.dk, tel.: +45 8715 7672, mobile: +45 5168 0554