Einfluß von Hauptbestandsbildner (Lolium multiflorum Lam., Lolium X boucheanum Kunth, Lolium perenne L. und Dactylis glomerata L.), Narbendichte, N‐Düngung und Zeit auf Ertrag, Energiedichte, P/E‐Quotient und Nitratgehalt

Abstract The influence of main species (Lolium multiflorum Lam., Lolium X boucheanum Kunth, Lolium perenne L. and Dactylis glomerata L.), sward density, nitrogen and time on yield, energy content, crudeprotein/energy ratio and nitrate content The aim of this investigation was to determine the influence of different rates of nitrogen fertilizer and of varied sward density on yield and chemical composition of some non‐perennial (Lolium multiflorum, Lolium X boucheanum) and some perennial species (Lolium perenne, Dactylis glomerata) in a field experiment. Excepted 600 kg N ha−l ‐ yr−1 the non‐perennial species produced the highest energy yields. At a fertilization level of 400 kg N ha−1 yr−1 had sward density an influence on energy yield of Lolium multiflorum. It appeared that almost the energy content of the Lolium species was higher than in Dactylis glomerata. In most cases there were little differences between the Lolium species. There was a positive correlation between the NFEcontent and the content of water soluble carbohydrates and the energy content which was depressed by applying increasing rates of fertilizer. Generally at the lowest rate of nitrogen used (200 kg N ha−1 yr−1) there were positive effects on crude protein/energy ratios. The crude protein/energy ratio was higher of Dactylis glomerata than that of the Lolium species. The nitrate content increased to critical values when applying 400 kg N ha−1 yr−1. Dactylis glomerata had the highest and Lolium perenne the lowest nitrate content. At high rate of fertilizer, plots with high sward density sometimes had higher nitrate contents than open swards. The results of the experiment indicate that there are differences in quality even between species with high performance. Regarding the quality of grass swards, future attention should be focused on the main species and on sward density.