The intensity of grassland management influences the mineral contents of the grass

The influence of different cutting frequencies and fertilization levels on mineral contents of meadow grass was investigated from 1994 to 1999. The following four variants were compared: 5 cuts and 300 kg nitrogen(N) per ha, 5 cuts and 150 kg N per ha, 3 cuts and 150 kg N per ha, 2 cuts and no fertilizer. Besides a commercial N-fertilizer slurry was also used. Half of the N amount came from the N-fertilizer and the rest from the slurry. Due to the slurry also phosphorus and potassium supply was different in the various treatments. In the 5-cut-variants the double fertilizer level resulted in lower calcium-contents and higher potassium-contents. On the other hand the fertilization intensity had no or only little effects on the phosphorus, magnesium, sodium, zinc and copper-contents. The reduction of the cutting frequency produced lower mineral contents. This is due to the change in botanical composition and to the age of the plants. The calculated correlations confirm, that with a higher proportion of grasses, a higher crude fibre content as well as with older forage (stade of development) the mineral contents decrease.