Winter Canola Yield Response to Supplemental Sulfur - Ohio.

Historically agronomic crops do not respond on most Ohio soils to supplemental S. Winter canola is known to have a larger demand for S than other crops. Since winter canola is a relatively new crop in Ohio little is known about the affects of supplemental S. To test the hypothesis that canola yields may be increased with supplemental S, the variety ‘Wichita' was established on the OARDC Northwest Research Station near Custar in 2003, 2004, and 2006; and at the North Central Research Stations near Fremont in 2006, 2007, and 2008. Each plot received 22.4 – 33.6 kg ha^-1 of fall N prior to planting and 112 kg ha^-1 of spring N prior to bolting. Sulfur was applied the same time as spring N at two rates (22.4 and 44.8 kg ha^-1). Ammonium sulfate was applied in 2003 and 2004 with the balance of urea to achieve 112 kg N ha^-1. Sulfur was applied as pelletized gypsum in 2006 – 2008; urea provided the N. Surface applied urea was the N source for treatments receiving no S. Leaves were collected at early pod development to determine S content. Experimental design was a completely randomized block with four replications. Statistical analysis was a simple ANOVA. Even though leaf analysis showed increase S content, yields were not significantly larger for any of the site years compared to plots only receiving N. Supplemental S should not be expected to increase winter canola yields for most Ohio soils.