Abstract
In South Tyrol (NE Italy) only a small proportion of available agricultural area is suitable for arable farming. Silage maize is commonly grown as a monoculture, although crop rotation with highly productive grass-clover leys is recommended. In this study, we analysed the botanical composition of different seed mixtures containing red clover over three years. We assessed the effects of replacing Festuca pratensis by Festulolium (×Festulolium braunii, cv. Hostyn), the Trifolium pratense cultivar ('Semperina', 'Spurt', 'Milvus') and three locally recommended grass-clover mixtures on the dry matter (DM) yield of sown and non-sown species, and their respective DM yield proportion. The trial was conducted in Dietenheim/Bruneck (South Tyrol, NE Italy) as a randomised complete block design with three replicates. The leys were cut four times per year. The initial high proportion of T. pratense of total DM yield declined over time. Our results suggest that the main factor driving the increase of non-sown species is the advancing age of the ley. The effect of the T. pratense cultivar became apparent in the third year, highlighting the importance of the cultivar selection to minimise the deviation of the desired botanical composition over time.