The study was conducted in the years 2005-2008 in the fields of the Experimental Station Swadzim (52^o26’ N; 16^o45’ E) belonging to ZDD Gorzyń, property of the Poznań University of Life Sciences. Two experiments with PR 39G12 maize cultivar were conducted in fields, where previously maize was sown in a six-years monoculture. The aim of the study was to evaluate the effects of natural fertilizers, straw or intercrop applied together with mineral fertilizers. We investigated whether this approach can reduce the negative effects of maize cultivation in monoculture system and at the same time help to increase the silage yield. The assessment of plant response was made on two soil classes. It has been shown that the use of natural fertilizers, straw or an intercrop (rye with vetch), reduced the negative effects of maize growing in monoculture and led to a significant increase in the dry mass yield of whole plants on IIIa soil class.

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