EN
The objective of this research project was to determine changes in quantitative occurrence of organic and mineral components affecting, directly and indirectly, fodder value following nitrogen fertilisation. Investigations were carried out in years 1997-2000 on two experimental plots. Analytical material was derived from two experiments. Experiment I was established on the collection of Holcus lanatus. Experiment II was of production nature and was established on a permanent meadow. Identical fertilisation with phosphorus (70 kg ha⁻¹) and potassium (60 kg ha⁻¹) were applied on both objects. In the case of nitrogen, two levels of fertilisation i.e. 50 and 100 kg ha⁻¹ per regrowth were applied. The applied nitrogen fertilisation levels reflected current opinions associated with meadow fertilisation containing Holcus lanatus. The assessment criteria of Holcus lanatus response to nitrogen fertilisation included: protein, sugars, cellulose, hemicelluloses, lignins, phosphorus, calcium, magnesium, potassium. The obtained results enlarge our knowledge about fodder value of Holcus lanatus. It turned out that the examined grass responded with positive changes of its chemical composition to nitrogen fertilisation. It can be assumed that fertilisation allows obtaining velvet grass, which is more friendly for animals. One application of 50 kg ha⁻¹ N dose can be recommended as a more rational amount to be used on meadows containing Holcus lanatus in their composition. The use of higher nitrogen doses failed to yield significant qualitative results. Holcus lanatus can accumulate nitrate nitrogen in amounts, which can be dangerous for animal health and productivity. That is why periodical control of its content is justified.