Impact of Traditional and Enhanced Efficiency Phosphorus Fertilizers on Canola Emergence, Yield, Maturity, and Quality in Manitoba

Impact of Traditional and Enhanced Efficiency Phosphorus Fertilizers on Canola Emergence, Yield, Maturity, and Quality in Manitoba

Project Leader: Dr. Cynthia Grant, Agriculture & Agri-Food Canada, AAFC Brandon Research Centre, PO Box 1000A,
Brandon, MB R7A 5Y3 Canada. E-mail: cgrant@agr.gc.ca
Project Cooperators: Gerhard Rakow and Jo-Anne Relf-Eckstein

The objectives of this research are to: (1) determine the relative effects of traditional and enhanced efficiency fertilizers in terms of safe rates for seed-row placement, and effects on crop yield, crop maturity, and seed quality and (2) determine if canola cultivars differ in response to seed-placed P fertilizer.

In the first study, a no P control was compared to standard monoammonium phosphate (MAP), a polymer-coated controlled-release product (CRP) MAP product formulated for broadacre agriculture, Avail®-treated MAP designed to sequester antagonistic ions and reduce soil P reactions, liquid ammonium polyphosphate, Avail® liquid P, and Polyon®-coated MAP formulated for horticulture. Each of the P sources was applied at 10, 20, 40, and 80 kg P_sO₅/ha. A single 0 kg P_sO₅/ha treatment was included for a total of 25 treatments per site. Seedling damage occurred with high rates of uncoated P fertilizer, with the damage mainly occurring on a fine sandy loam (FSL) textured soil, but not on the clay loam textured soil. Both the CRP and Polyon®-coated product prevented seedling damage. Seed yield on the FSL soil increased with low rates of liquid P then decreased when rates were increased to 40 kg P_sO₅/ha or higher. Seed yields on the FSL tended to be higher with high rates of Avail® MAP than with the high rates of CRP or uncoated MAP.

In the second study, yellow- and black-seeded canola cultivars were seeded following the methodology described for the previous study. Yellow-seeded canola was slightly more prone to reduced emergence with seed-placed MAP than was the black-seeded cultivar. There appears to be a number of differences in the sensitivity and responsiveness of the black- and yellow-seeded canola cultivars to seed-placed P. Samples have been submitted for quality analysis. MB-22