Objective
To demonstrate the yield and quality response of canola to in-furrow and foliar applications of different micronutrients in multiple soil zones in Saskatchewan. To demonstrate to producers the importance of soil testing and tissue testing as tools for evaluating the potential need for micronutrient products in canola.
Project Description
A small-plot randomized trial with four replicates was conducted at five locations in SK to evaluate the response of canola to the micronutrients Copper (Cu), Boron (B), and Zinc (Zn). Micronutrients were either applied in-furrow at seeding time or foliar at bolting. The locations were Melfort (NARF), Redvers (SERF), Scott (WARC), Indian Head (IHARF), and Swift Current (WCA). Data collection consisted of environmental conditions, soil sampling, stand establishment, tissue testing, maturity, seed yield, and oil. The spring of 2025 was drier and warmer (May), while conditions cooled off in the summer (June-July), and warmed up near maturity (August). Micronutrient applications never significantly affected plant stands, maturity, yield or oil at any location. Despite some locations having low soil B, tissue tests for all treatments at all sites were sufficient. No sites demonstrated low soil Cu; however, sites with moderate Cu, still had tissue tests with Cu deficiency. Sites with soil Zn deficiencies often had low tissue test Zn, except for one location. Applying micronutrients often increased their concentration in tissue test results; however, this never translated into a yield response. Overall, canola showed very little response to B, Cu, and Zn across several locations in SK, despite low soil test results.
Grower Benefits
Overall, canola showed very little response to in-furrow and foliar applications of the micronutrients B, Cu and Zn at Melfort, Redvers, Scott, Swift Current and Indian Head, SK in 2025. Despite low soil B at three locations, tissue test results came back for all sites and treatments as sufficient. In contrast, all sites had moderate to high Cu in their soils based on spring sampling; however, sites with moderate soil Cu had multiple treatments deficient in plant tissue Cu from results of tissue testing. For Zn, Indian Head and Redvers, both had tissue tests where the majority of treatments were beneath sufficiency range, which was not surprising, as both locations had soils deficient in Zn; however, Swift Current also had Zn deficiency in their soil, but all treatments came back with sufficient Zn in their tissue samples. The overall effect of micronutrient applications was hard to evaluate on tissue sample results as statistical analysis could not be conducted as composite samples were collected. However, at every location, applications of B, Cu, or Zn did tend to increase the ppm of each respective nutrient in the tissue samples in relation to the control. Despite low tissue levels of micronutrients at some locations and micronutrient applications often increasing tissue levels of B, Cu, and Zn, there were never any significant differences for plant density, days to maturity, grain yield and oil of canola. These results suggest that regardless of low soil test and tissue test results for B, Cu, and Zn, canola is unlikely to demonstrate significant responses to in-furrow and foliar applications in SK. While it is advised for farmers and agronomists to monitor soils and crops for potential deficiencies as responses can be extremely site and year specific, preventative micronutrient applications across broad acres cannot be recommended based on the results of this demonstration.
