Correcting sulphur deficiency on canola during the growing season
A field experiment was conducted in 1998 at two sites (Porcupine Plain - Gray soil, and Star City - Dark Gray soil) in northeastern Saskatchewan to determine the influence of rate, time and method of application of sulphate-S fertilizer in increasing yield and quality of canola, and to find if canola yields can be restored by applying S fertilizer at different growth stages during the growing season on S-deficient soils. At Porcupine Plain, there was a marked seed yield response of canola to S fertilization. Increases in canola yield from S fertilizer were generally similar for various times or methods of application. At Star City, canola yield increased moderately with application of S fertilizer, but top-dress application gave lower yield increase than foliar applied S at bolting and at flowering at the 15 kg S/ha rate. At this site, yield increase was lower when S fertilizer was applied at flowering compared to that obtained at bolting or at sowing, and top-dress application at flowering gave the lowest increase in seed yield. The preliminary assessment of results (based on only one year’s data) indicates that canola yields can be restored on S-deficient soils with application of sulphate-S fertilizer as late as flowering stage, provided there is enough rainfall after top-dress application to move the S fertilizer into the subsoil where roots can intercept it. Foliar application of S seemed a more powerful technique to restore seed yield in S-deficient canola when S fertilizer is applied late in the growing season, especially when there is inadequate rainfall.
The following license files are associated with this item: