THE PERFORMANCE OF ECOLOGICAL, INTEGRATED AND CONVENTIONAL NUTRIENT MANAGEMENT-SYSTEMS IN CEREAL CROPPING IN FINLAND

A field trial was conducted during 1989-1992 in order to study the per formance of cereal crops under three different nutrient management sys tems. The systems were divided into conventional, integrated, and ecol ogical groups according to the fertilizer/organic organic manure appli cation ratio and crop rotation. Each group was further divided into th e crop-production- and animal-production-oriented rotations, the latte r including also leys. Average cereal grain yield of the crop-producti on-oriented rotation was 5% higher than that in the animal-production- oriented one. However, this difference was not significant. Convention al nutrient management systems produced 6% and 32% more cereal grain t han the integrated and ecological nutrient management systems, respect ively. Difference to the ecological nutrient management system was sig nificant. The 2-year leys in the integrated nutrient management system produced 8% more dry matter than both the conventionally and the ecol ogically managed leys. This difference was not significant. Nitrogen y ield of the integrated leys exceeded that of the conventional leys by 30% and the ecological leys by 10%. The economic result of the systems indicated greater annual variation in the ecologically managed system s. However, by taking into account 30% surcharge on the ecologically p roduced products, the greatest gross margin/crop was achieved under ec ological nutrient management. Gross margin/crop in the conventional an d the integrated nutrient management systems did not differ significan tly. A significant part of the mineral fertilizers can be replaced wit h animal manures, legume undercropping or green fallowing. Grass-legum e leys also enabled successful reduction in mineral fertilization.