The area under maize is expanding rapidly and the vigorous plant needs a cover crop that can reduce the post-harvest leaching of nitrogen. The search is therefore on to find a cover crop to co-exist with maize.
The maize crop is becoming increasingly popular in Denmark. The plant is high-yielding and can be used both as biomass for biogas production and as animal fodder. Maize does give a problem with subsequent leaching of nitrogen from bare harvested fields in the autumn, therefore scientists at Aarhus University are searching for a cover crop that can work together with the maize and also capture nitrogen. This is not a simple task as maize grows fast and tall which shades out any other crop.
It might look very peaceful with a dual crop of maize and for instance ryegrass, but in reality it is a battle of life and death between them. Hopefully it will end with a peaceful co-existence, explains senior scientist at Aarhus University, Elly Møller Hansen.
In a video explaining the research, conducted on a 41 year old field experiment at Jyndevad Research Station. The experiment looked at the residual effects of various soil tillage methods, this was co-financed by EU through the European Regional Development Fund.
Among the other crops that scientists were looking include clover, grasses, fodder radish and winter rape. The purpose being quite clear: “our aim is to improve nitrogen uptake in cover crops in maize by up to 10-20kg per hectare, compared with current practise and therefore reducing nitrogen leaching by around 20kg per hectare,” says Hansen.
Further details of this experiment can be found at the Aarhus University website.