Produkcyjność zbiorowisk trawiastych użytkowanych kośnie i pastwiskowo na trwałych i przemiennych użytkach zielonych

Abstract

The objective of the study was to determine the yields and forage value of permanent grasslands – meadow and pasture – and of grass leys– used either as hay or for grazing. Fivecomponent mixtures with meadow fescue (40%), perennial ryegrass (30%), timothy, cocksfoot, kentucky bluegrass (10% each) that differed for the purpose of their component varieties – either for hay or for grazing were sown in 1998 as ley. In their full production years (1999–2002) they were compared for yield and crop quality with permanent grasslands – a meadow and a pasture. Four harvests of the sward were made each year. The pasture mixture and the permanent pasture were grazed by dairy cattle. An area destined for grazing was 450 m2. The yield was measured based on test cuts into an area of 22.5 m2. Sward density, dry matter yield and nutritional value of the forage as well as utilization of the pasture by dairy cows were determined in the study. Weather conditions in the study period were characterized by highly variable rainfall and air temperature. Sward density was found to vary with kind of grassland, permanent pasture was characterized by higher density than the pasture ley. The yield and crop quality of the hay mixture was comparable to the output of the permanent grassland, whereas the permanent grassland gave better yields then the pasture mixture ley. Likewise, the indigestion of the forage by dairy cows from the permanent grassland was better. Permanent grasslands, especially the pasture, were assessed to be more reliable sources of forage, especially during variable weather conditions, than more vulnerable leys.