Evaluation of four zero-tillage drills equipped with different row openers for seeding winter wheat in the semi-arid prairies

Abstract

On the Canadian prairies, in the warm, southern province of Alberta, winter wheat ( Triticum aestivum L.) has traditionally been grown on conventionally tilled fallow. Recent research into the adaptation of this crop to the colder regions of Saskatchewan has led to recommendations for direct seeding into stubble, or into chemically prepared fallow where vegetation is controlled with herbicides. A factorial combination of four zero-till drills differing in seed row openers, and three seeding rates was used to study plant establishment, grain yield and grain quality of winter wheat in the semiarid Brown soil zone of Saskatchewan. Three years of experiments for stubble-seeded winter wheat were carried out on: (a) a medium-textured soil (Aridic Haploboroll) at Swift Current; (b) a coarse-textured soil (Typic Haploboroll) at Cantuar; (c) a fine-textured soil (Vertic Haploboroll) at Stewart Valley. On all soils, wheat was direct-seeded into stubble. On the medium-textured soil, the experiments were also seeded into chemical fallow. All seed drills left sufficient stubble standing to aid snow trapping, thereby aiding winter survival and adequate plant stands. Greater numbers of plants were established on the chemical fallow plots because of greater soil water availability. Generally, the highest plant densities were obtained with the Versatile Noble 2000 hoe drill equipped with zero-till points; however, grain yields for this treatment were the lowest. We speculated that this was due to greater soil disturbance resulting in a greater rate of soil moisture loss by evaporation. The highest grain yields were obtained with the Swift Current zero-till offset disc drill followed by the Swift Current zero-till hoe (Thompson slim line knife), air seeder (Dutch banding knife), and Versatile Noble 2000 hoe drill (zero-till points). Plant density increased linearly with seeding rate from 40 to 80 kg ha −1. The highest yields of stubble-seeded wheat were obtained at the highest seeding rate in a wet year, but in a hot dry year the converse was true. On chemical fallow neither drill nor seed rates significantly influenced grain yields. Low seeding rates or low numbers of plants established led to delayed maturity, lower kernel test weight, and lower grain protein concentration at the silt loam site but not at the fine sandy loam site. Protein was not affected by type of drill. We concluded that all of the drills tested were suitable for seeding winter wheat on chemical fallow land. However, when seeding on stubble, seeding rate should be adjusted upward if using the air seeder. The Versatile Noble 2000 hoe drill with zero-till points caused too much soil disturbance when seeding stubble and was considered less suitable for seeding winter wheat in the Brown soil zone.