Seeding Depth in Relation to Plant Development, Winter Survival, and Yield of No-Till Winter Wheat

Successful production of winter wheat (Triticum aestivum L.) on the Canadian prairies requires no-till seeding into standing stubble (stubbling-in) in order to trap snow and thereby prevent low temperature freezing injury of the young seedlings. In the present study, a total of 14 no-till winter wheat field trials were seeded into standing stubble on several Saskatchewan soil types (Aridic, Typic, Vertic, and Udic Haploborolls, and Udic Agriborolls) to investigate the effect of seeding depth on plant growth and development. The influence of seeding depth and date on winter wheat growth and development were also investigated in a hand-planted trial on conventional summerfallow. Increases in seeding depth as small as 17 mm resulted in significantly deeper crown placement and delayed plant emergence. Delayed seeding into cooler soils was associated with slower plant emergence and shorter sub-crown internodes than earlier seeding at warmer soil temperatures. Consequently, delayed deep seeding resulted in very slow plant emergence, a reduction in the number of tillers plant⁻¹ and fewer heads m⁻² the following year. Winter survival was significantly higher for shallow seeded treatments in four of seven trials that experienced differential winterkill. A significant yield advantage (11%) was observed with shallow seeding in four of six trials that escaped serious winter damage. In contrast, improved winter survival and/or yield advantages were never obtained with increased seeding depths. These observations demonstrate that seeding shallow (10–25 mm) at the recommended date is necessary to optimize plant establishment in the fall, minimize the risk of winter damage, and maximize yield potential of no-till winter wheat produced on the Canadian prairies. Supported in part by a grant from the New Crop Development Fund of Agriculture Canada. Contribution from the Crop Development Centre, Univ. of Saskatchewan.