Tillage system and seeding time effects on forage and seed yield of alfalfa and bromegrass

Perennial forages are an important component for the cropping systems of the Parkland region in the Canadian prairies, but only a few studies have reported on direct seeding of forages in northeastern Saskatchewan. The objective of this study was to compare the effects of tillage (conventional tillage, CT, and zero tillage, ZT) for seedbed preparation and different seeding times (October 1993, May 1994, and June 1994) on forage and seed yield of alfalfa (Medicago sativa Leyss) and bromegrass (Bromus inermis Lyess) on Gray Luvisol (Typic Cryoboralf) soils (sandy at Gronlid and clayey at Ridgedale) in northeastern Saskatchewan. Visual inspection of plant stands in the establishment year indicated that plant densities were generally higher under CT than ZT and with spring than autumn seeding. Forage yield in 1994 was greater under ZT than CT for alfalfa at both sites and for bromegrass at Ridgedale. In 1995 and 1996, tillage had no effect on forage yield in most cases. The 3-year forage production was greater under ZT than CT for alfalfa by 647 and 770 kg ha-1 at Gronlid and Ridgedale, respectively, and for bromegrass at Ridgedale (by 697 kg ha-1), with the opposite result at Gronlid (by 237 kg ha-1). The effect of seeding time on forage production was not consistent. The seed yield in 1995 and 1996 was somewhat greater with ZT than CT, with autumn than spring seeding, and with May than June seeding for alfalfa, whereas the opposite was true for bromegrass, except at Ridgedale when autumn seeding produced greater seed yield than spring seeding. In summary, the lower plant population under ZT than CT in the establishment year did not necessarily result in lower forage and seed yield of alfalfa and bromegrass, suggesting that ZT can replace CT for forage production, and seeding time effect was mainly observed in the first year. Copyright © Taylor & Francis Group, LLC.