Succession changes of temporary grass stands on set-aside land

The mixtures of Bromus marginatus Nees ex Steud. + Coronilla varia L., Festuca pratensis L. + Lotus corniculatus L., Dactylis aschersoniana Graebn. + Trifolium repens L., Arrhenatherum elatius (L.) P. Beauv. ex J.S. et K.B. Presl + Medicago lupulina L. were sown in rows of 125 mm in the year 1997 in Prague (chemozem, altitude 281 m a.s.l., average precipitation is 472 mm per year, average year temperature 9.3degreesC). The stands were one or three times per year cut with the mass removing or one or two times mulched. Botanical composition (by weight method), number of present species and agrobotanical groups (grasses, legumes, other dicotyledonous) coverage were measured during 6 years of vegetation. The species number was highest on plots cut 3 times (6-17), it increased linearly. The sown species share in the dry mass yield was 75-99% and the share of grasses decreased linearly with time. The significantly highest dry mass yield was reached when mulched two times per year Bromus marginatus Nees ex Steud. with Coronilla varia L. (till 14 t/ha The stands coverage was 43-80%.