EN
Under conditions of 4-year cut performance, Lolium perenne share in species composition of studied mixtures varied and depended on the cultivar, harvest date and performance duration with the tendency to decrease in last years of study. Among considered cultivars, only 'Maja', 'Solen' and 'Anna'. showed significantly better durability in thc cut performed sward under experimental habitat conditions. Other grass species (timothy, cocksfoot) sown in studied mixtures also oceurred in grass sward, and their share less depended on ryegrass presence or absence (control mixture). The lack of Lolium perenne in mixture composition or its gradual out of the sward was responsible for the increase of other grass species share not considered in mixtures (particularly Poa pratensis).