Row Spacing and Seeding Rate Studies in No-Till Winter Wheat for the Northern Great Plains

Abstract

The risks of winter kill in winter wheat (Triticum aestivum L.) for the Northern Great Plains of the Canadian prairies can be virtually eliminated when using a no-till production system. Because of the needs for no-till, a re-examination of the effects of row spacing should be conducted. Narrow row spacings can cause equipment design and trash clearance problems under heavy residue. The objectives of this study were to determine whether the grain yield of winter wheat could be maintained at wider row spacings by varying seeding rates and P fertilizer and using a fungicide seed treatment. The study consisted of three separate trials that were all conducted at the Indian Head Research Farm in Saskatchewan on an Indian Head heavy clay soil (rego black chernozem Udic Haploboroll). The first trial examined eight seeding rates and the effect of the seed treatment Vitavax Dual Powder. The second trial examined three row spacings and six seeding rates for three growing seasons. The third trial involved three row spacings, three seeding rates, and three rates of seed-placed P over 2 yr. Use of the seed treatment increased grain yield by 4 to 6% in 2 of 3 yr. Optimum seeding rate was about 90 to 120 lb/acre, at which the maximum grain yield was achieved in 6 out of 8 yr. On average, the 8 and 12 in, row spacing resulted in an equivalent or higher (8%) grain yield than the 4 in, row spacing. The effect of row spacings was consistent at various seeding rates, with no row spacing × seeding rate interactions. Seed-placed P increased grain yield by 21 to 30%. In the more humid regions of the Northern Great Plains where heavy crop residue may disrupt the seeding operation, wide row spacing coupled with proper seeding rates, P fertilizer, and a seed treatment, would ensure successful winter wheat production.