Yield and forage quality of red clover (Trifolium pratense L.) cultivars in the lowland and the mountain regions

Six Trifolium pratense L. cultivars, five diploid and one tetraploid, were grown in the lowland region (123 m altitude) and the mountain region (650 m altitude). Dry matter (d.m.) and green mass (g.m.) yield, stem height and leaf proportion were assessed from each of the three growing seasons. Chemical composition was assessed from the average samples of all cuts in the second year of the experiment. Greater green mass (54.14 t/ha) and dry matter yield (9.86 t/ha), stem height (0.61 m), crude protein (157.6 g/kg), crude fiber (222.9 g/kg), crude ash (100.68 g/kg) and crude fat (30.09 g/kg) content were observed in the mountain region, compared to the lowland region (45.61 t/ha g.m. 8.92 t/ha d.m. 0.59 stem height, 156.38 g/kg crude protein, 216.6 g/kg crude fiber, 94.85 g/kg crude ash, 24.98 g/kg crude fat). The greater leaf proportion (47.2%) and nitrogen free extract content (420.13 g/kg) were observed in the lowland region compared to the mountain region (42.95% and 402.99 g/kg, respectively). A significant location x cultivar interaction was found for all investigated parameters except for leaf proportion.