A comparison of drills for direct seeding alfalfa into established grasslands.

Abstract

Information is presented on the suitability of various drills for direct seeding into permanent pastures and rangelands in Saskatchewan. Strips of sod 30 to 100-cm wide were killed during the growing season by glyphosate (N-[phosphonomethyl] glycine) in grazing lands at several sites in Saskatchewan. Six drills: 1 with a powered disk furrow opener, 2 with hoe openers, and 3 with rolling disk openers were used to seed measured amounts of alfalfa (Medicago sativa L.) seed in the killed strips in late fall of the same year or early the subsequent spring. Drill performance was assessed during the seeding operation, and emerged seedlings were counted early the following growing season. Seedling emergence ranged from near 0 to 48% of seed sown. Soil moisture conditions in early spring, which in turn were a function of winter precipitation, were a major limitation on seed germination. All of the furrow-opening mechanisms were capable of placing seed at a suitable depth for successful establishment in some situations. The best seedling emergence was obtained with drills having each opener suspended independently with sufficient weight to penetrate dead thatch and hard ground, and with mechanisms to control seeding depth and pack the soil around the seeds.