A comparison of environmental, soil fertility, yield, and economical effects in six cropping systems based on an 8-year experiment in Norway

Abstract

Development of environmentally and economically sound agricultural production systems is an important aim in agricultural policy and has a high priority in agricultural research worldwide. The present work uses results from the first complete crop rotation period (1990–1997) of the Apelsvoll cropping system experiment in south-eastern Norway to discuss the effect of cropping systems and their management practices on environment, soil fertility, crop yields and the farm economy, and how this knowledge may be used to develop a more sustainable agriculture. The experiment includes conventional arable (CON-A), integrated arable (INT-A), ecological arable (ECO-A), conventional forage (CON-F), integrated forage (INT-F) and ecological forage (ECO-F) cropping systems which were established on model farms of 0.2 ha. On the basis of nutrient runoff, soil erosion and pesticide contamination, the following ranking from the most to the least favourable was made for environmental effects: INT-F>ECO-F>ECO-A>INT-A>CON-F>CON-A. Environmental effects such as N and P runoff losses were very much linked to the proportion of ley in the system. Thus, major improvements to reduce the effects of agriculture on nutrient runoff, cannot be achieved without changing the cropping systems in the direction of more mixed farming with reduced cropping intensity. The nutrient balance calculations showed that there were considerable deficits in the ecological systems, a fact which must be taken into consideration in the development of sustainable ecological cropping systems. The yield reduction experienced with integrated and ecological cropping, relative to conventional cropping, was smaller for forage crops and potatoes than for cereals. This suggests that it is easier to maintain the yield level by reduced cropping intensity in mixed farming systems with livestock than in arable farming systems without livestock. Because of the premium prices and government subsidies to ecological farming, the economic results were equally good in the ecological systems as in the conventional ones. Economically, integrated farming was less favourable than the other systems. It is concluded that, overall, integrated and ecological forage systems results in the least environmental harm, and based upon the present government subsidies, the forage systems also seem the most profitable, along with the ecological arable system.