The aim of this study was to compare to two organic manures (farmyard manure and mushroom compost) in the aspect of their effect on the changing of botanical composition as well as the yields of the meadow sward. Organic maniuring was applied once in the spring of 1999 in the quantity of 10 tons of organic mass per hectare. Every year three cuts were harvested. The results of this study showed that mushroom compost had high nutritional value but in comparison to farmyard manure this value was a little smaller. Mushroom compost influenced the botanical composition of the sward as well as on the yields.