Effect of fertilization on the quality of hay dry matter tn the association Lolio-Cynosuretum typicum

In the period from 1992 to 1995, primary and secondary metabolic contents o f anthropogenically influenced semi-natural grasslad (association Lolia-Cyn osuretum typicum) of the Strazovske vrchy locality were observed. Non-ferti lized control and variant fertilized with 90 kg N.ha(-1) + 30 kg P.ha(-1) w ere compared in our experiment. The plants were used three times during the ir vegetation period: first mowing - in the growing phase of the beginning of tasseling of the prevailing grass types; second mowing - four or five we eks later; third mowing - six or eight weeks after the second mowing. Chemi cal analyses carried out by the laboratories of the Research Institute of A griculture in Nyone and Department of Fodder Growing, Slovak University of Agriculture in Nitra showed that dry non-fertilized semi-natural grasslands contained on average 14.25 to 16.45% crude protein, 8.88 to 10.12% PDI, 5. 49 to 5.90 MJ.kg(-1) dry matter NEL, 20.03 to 21.03% fibre, 5.50 to 6.08% l ignin and that dry matter contained 70.27 to 72.58% of digestable organic m atter. The fertilized variant produces the average value of dry matter of h ay with equivalent crude protein content and PDI compared with non-fertiliz ed control with a significant low value of NEL and higher value of lignin c ontent, which is also reflected in its lower digestable organic matter. A r elatively high portion of dicotyledon types (40 to 50%) in decayed state wa s shown by high value of IANP with a maximum of 165.05 in the second mowing in the non-fertilized variant and 175.15 in the third mowing in the varian t fertilized with nitrogen and phosphorus. Fertilized plants contain on ave rage 15.12 to 16.85% crude protein, 9.51 to 10.07% PDI, 5.42 to 5,69 MJ.kg( -1) dry matter NEL, 20.28 to 21.79% fibre and 5.77 to 6.20% lignin in dry m atter. Digestion of organic matter is rated as good (69.49% in the third mo wing and 71.39% in the first mowing).