Maize cultivation with reduced environmental impact

A better utilisation of slurry can contribute to a sustainable maize production that uses less mineral fertiliser without negative effects on yield.

2018.10.30 | Janne Hansen

Maize needs to have access to nutrients right from the beginning to give it a good start in life. Photo: Janne Hansen

In order to give maize a good start in life, it is necessary to provide it with sufficient nutrients right from the beginning. This is the reason many farmers apply mineral fertiliser in the spring. However, using starter fertiliser can pose challenges and risk impacts on the environment and climate. 

A new project, which includes researchers from Aarhus University, is working on solving this problem by developing methods for better utilisation of slurry as the primary source of nutrients.   The aim of the project, which is led by Seges, is to reduce the impact on the climate and environment by ensuring that future maize cultivation is carried with a reduced input of phosphorous and nitrogen fertilisation. 

One of the challenges facing farmers is that there is a ceiling on how much phosphorous that may be applied per hectare. The ceiling protects the environment from phosphorous leaching but limits the possibilities of applying starter fertiliser to the maize without forcing livestock farmers to export some of the manure from the farm. Such export of manure can be costly as more transport is needed, and the farmer would then have to buy extra N mineral fertiliser to replace the exported manure.  

Another challenge is that surplus nitrogen can either be leached to the aquatic environment or transformed to the greenhouse gas nitrous oxide and emitted to the atmosphere. 

Slurry is suitable

Slurry is a suitable alternative to mineral fertiliser as a good nutrient source, but must be handled so that the plants can utilise the nutrients in the slurry as well as possible. The aim of the project is to develop a slurry injection system that ensures precise placement of the slurry prior to sowing so that the maize plants have faster and better access to the nutrients in the slurry. 

Previous field trials carried out with specialised test equipment at Aarhus University have shown that slurry works at least as well as mineral starter fertiliser, but there is no suitable application equipment on the market that farmers and contractors can use. There is a great need for development and documentation of injection equipment that works in practice. 

Precise placement of the slurry is crucial to subsequent correct placement of the maize seeds in relation to their distance to the slurry. The seeds will die if they are sown directly in the slurry. If they lie too far away from the slurry line, they will not be able to utilise the nutrients in the slurry sufficiently in the beginning of their growth period. 

In collaboration with the company Samson Agro, the Department of Engineering at Aarhus University will develop the injection technology that is required for correct placement and distribution of the slurry. 

Researchers from the Department of Agroecology will investigate the effects of the new injection technology on maize production, nutrient uptake, and development of greenhouse gases.   


Facts about the project

Name: Gyllemajs (Udvikling af husdyrgødningsteknologier til bæredygtig dyrkning af majs) In English: SlurryMaize (Development of animal manure technologies for sustainable production of maize)

Funding: 8.5 m DKK from the Green Development and Demonstration Fund (GUDP)

Partners: Seges (project leader) Aarhus University, Samson Agro, Danish Contractors and Entrepreneurs, Varde Maskinstation (contractor)

Duration: 3.5 years (1 July 2018-31 December 2021)


For more information please contact

Senior Researcher Peter Sørensen, Department of Agroecology, email: ps@agro.au.dk, telephone: +45 8715 7738

Senior Researcher Søren O. Petersen, Department of Agroecology, email: sop@agro.au.dk, telephone: +45 8715 7756, mobile: +45 2812 4304

Senior Adviser Tavs Nyord, Department of Engineering, email: tavs.nyord@eng.au.dk, telephone: +45 2060 5533

Agro, Crops, Technology, DCA