Etablering av frøeng av bladfaks (Bromus inermis) i renbestand og med bygg som dekkvekst: Virkning av såmengder av bygg og bladfaks

摘要

Four seeding rates (5, 15, 25 and 35 kg per hectare) of smooth bromegrass (Bromus inermis Leyss.) cv. Lofar were combined with three seeding rates (0, 120 and 200 kg per hectare) of a spring barley (cv. Pernilla) cover crop in seed production trials established in 1984, 1985, 1986 and 1987 at Apelsvoll Research Centre, division Landvik, in SE Norway (58°N). While all trials were harvested in the seeding year and the first year of ley, three trials were harvested in the second and only two trials and third year of ley. . Cover crop seeding rate had no significant influence on barley yield, which averaged 4440 and 4610 for seeding rates of 120 and 200 kg per hectare, respectively. The use of cover crop strongly reduced seed yield in the first year of ley; from an average of 320 kg per heactare when sown in pure stand to 120 and 80 kg per hectare when undersown in barley at rates of 120 and 200 kg per heactare, respectively. Panicle number in the the first year of ley dropped similarly. While the main effect of smooth bromegrass seeding rate on seed yield was not significant, a significant interaction indicated that the yield reducing effect of a barley cover crop in the first year of ley was more pronounced when smooth bromegrass had been sown at low than at high seeding rate. None of the treatments had any effect neither on seed yield in the second or third year of ley, nor on thousand seed weight or germination in any year.