Feasibility of a wider row spacing and recommended nitrogen in no-till wheat

Abstract

The optimal row spacing aims to maximize profitability by balancing the reduction in production costs from a wider row spacing against a potential decline in yield and increased weed pressure. A wider row spacing should increase area seeded per day, improve residue flow around seeder openers and the success of seeding between stubble rows. This study investigated the feasibility of a wider row spacing by studying the effects of row spacing (25, 30, 35, 40 cm) and N fertilizer rates (20, 40, 80, 120, 160 kg N ha−1) on development, yield, and quality of spring wheat (Triticum aestivum L.). The study was a two factorial in randomized complete block design. The experiment was conducted at Indian Head, SK, from 2013 to 2016. Row spacing affected plant, head, and seed density; however, the effects were generally inconsistent. One exception was biomass, which decreased as the row spacing increased in 3 of the 4 yr. Grain yield declined in 1 of the 4 yr, with the largest portion of the decrease occurring as the row spacing increased from 30 to 40 cm. As expected, increasing N rates produced greater grain yield, biomass, and grain protein. In conclusion, this study found that in most years the row spacing can be widened past 30 cm without a negative impact on grain yield in a no-till cropping system. However, to determine the probability of a grain yield decrease as row spacing is increased, a larger study over a wider geographic region is needed.