Norwegian Journal of Agricultural Sciences : the Apelsvoll cropping system experiment

A cropping system experiment aimed at developing cropping systems which minimize nutrient leaching and maximize food quality and economy was started at Apelsvoll Research Centre in southeast Norway in 1990. The experiment includes arable and forage crop systems with conventional, integrated and ecological cropping. The systems differ in crop rotation, fertilization, soil tillage and plant protection, and are established on «model farms» which are equipped with field lysimeters for measuring drainage and surface runoff. Nitrogen runoff results for the first four-year experimental period revealed that on average for all cropping systems, the annual losses of total-N varied from 12 to 36 kg ha'. There were cropping system differences in nitrogen losses, and the losses were higher in the conventional and integrated arable system and in the conventional forage system than in the ecological arable system and the integrated and ecological forage system. It appears that crop rotation and management factors such as use of farmyard manure, fertilizer level and tillage system are the determinants in the risk of leaching. Weather factors, such as precipitation, had an even greater effect on nitrogen losses than the management factors, which differed between the cropping systems.