Use of six annual companion crops to establish alfalfa–timothy mixtures at different seeding dates

Abstract

AbstractOat (Avena sativa L.) is the main species used as a companion crop when establishing perennial forages in eastern Canada, and, although other annual species are used, they have not been systematically evaluated. A field study was conducted across five environments to contrast the use of six annual species (berseem clover, Trifolium alexandrinum L.; forage peas, Pisum sativum L.; annual ryegrass, Lolium multiflorum Lamarck; oat; Japanese millet, Echinochloa esculenta [A. Braun] H. Scholz; sudangrass, Sorghum × drummondii [Nees ex. Steud.] Millsp. & Chase) as companion crops for the establishment of alfalfa (Medicago sativa L.)‐timothy (Phleum pratense L.) mixtures. The control treatment consisted of the perennial species seeded without companion crop. Treatments were seeded at three dates and evaluated during the seeding and post‐seeding years. The performance of the six companion crops evaluated herein varied depending on the seeding date and the environment. For a mid‐May to early June seeding total seeding year forage mass was greatest with use of oat, Japanese millet, or sudangrass as companion crops; for a mid‐June to late June seeding with Japanese millet or sudangrass; and for a late July to early August seeding with oat or Japanese millet. These species, however, reduced in some environments seeding year alfalfa or timothy mass compared to a control seeded without a companion crop. Such reduction was also observed in some environments in the first post‐seeding year. Companion crop choice to establish alfalfa–timothy mixtures needs to take into consideration seeding date and forage needs on the short term versus the long term.