Produktie en voederwaarde van gras bij gebruiks- en bemestingsbeperkingen voor natuurbeheer

The effects of restrictions in grassland management on behalf of nature conservation were studied. In this thesis it was investigated to which extent soil fertility, botanical composition, growth curves, dry matter production, chemical composition, digestibility and nutritive value were affected by a delay of first cutting date and restricted amounts of N-, P- and K-fertilizers. The average number for growing days to reach certain amounts of dry matter during growing season and the consequences for chemical composition and nutritive values are presented

On the studied humous soils with a sufficient phosphate (P) and potassium (K) fertilization but without nitrogen (N) application the dry matter production was c. 8 ton.ha ^-1.year ^-1. Without P- and K-fertilization the production decreased sharply within 2 to 4 years. The digestibility of the grass was strongly affected by growing stage as well as by botanical composition of the sward. The differences in digestibility between (indigenous) grass species were considerable. At any time Lolium perenne had the highest digestibility at a certain crude fibre content.