Premises
Modern agriculture is often specialized into either crop production alone or livestock farms – dairy or meat production. Mineral fertilizers and chemical crop protection products and large amounts of energy from fossil fuels are used. A problem often related to agricultural crop production is that nitrogen and phosphorus can be lost to the environment. Moreover, concentrations of cadmium in arable soils have increased during the last decade.

Research
Within FOOD 21, the turnover of beneficial and harmful elements on farms is being investigated. This applies particularly to plant nutrients and heavy metals. In which management systems do they increase in soil, and in which do they show a decreasing trend? These are important questions which need to be answered.

Nitrogen and phosphorus are two key areas
In the more environmentally sound crop production systems of the future, that include more winter-cover crops and cultivation of green manures, the amount of organic matter in the soil will most likely increase. Researchers are now investigating how the decomposition of green manures can be controlled and used immediately by the current crop as it is released, thereby preventing losses to both air and water.
Phosphorus leaching is also being investigated to improve our understanding of this process. It has been shown that large amounts of phosphorus can be transported down through vertical cracks in heavy clay soils into drainage tiles. It has also been shown that through a symbiosis with mycorrhizal fungi, phosphorus can be better utilized in soils with low phosphorus contents.

Professor Lars Bergström is in charge of research in this area.
Lars.Bergstrom@mv.slu.se

Project and contact person:
Researchers within the area of crop production


June 24, 2004. mat21@slu.se