Field Evaluation of Urea Compared to Enhanced Urea Products

The experiment was conducted in the 2009 field season at a field site in West Central Saskatchewan in the Dark Brown soil zone near Kindersley, SK. The trial evaluated the yield response of canola (food quality oil rapeseed) to regular urea and polymer coated urea that were both side banded at planting, at rate of 40 lb N / acre (typical N rate for stubble seeded canola in the region).


15 Feb 2010

2009 Annual Interpretive Summary

Field Evaluation of Urea Compared to Enhanced Urea Products, 2009

A field experiment was conducted with canola near Kindersley, Saskatchewan, as part of an undergraduate research project of the University of Saskatchewan. Three different N fertilizer forms were evaluated, including Super Urea (including both urease and nitrification inhibitors), urea treated with Nutrisphere-N® (a polymer coating), and Environmentally Smart Nitrogen or ESN® (designed as a semi-permeable, polymer-coated urea source). The sources were compared to conventional urea applied at 44 kg N/ha, along with a zero-N control. All fertilizers were side-banded at the time of seeding. Canola was seeded in May, but due to drought conditions germination was delayed until rains arrived in mid-June. Mid-season plant samples were collected at the end of July, and canola reached maturity and was harvested at the end of September. Plant materials were analyzed for N and P content and soil samples 0 to 30 cm and 30 to 60 cm were removed from the plots in October after harvest.

Both the conventional urea and coated forms (Nutrisphere-N® and ESN®) resulted in about 400 kg/ha more yield compared to the control. Nitrogen uptake was slightly higher in the ESN® and Nutrisphere-N® treatments compared to conventional urea, suggesting that they had slightly enhanced N recovery. However, the highest yield and N uptake was obtained with Super Urea. This may be attributed to the presence of the urease and nitrification inhibitors. Under the conditions of the experiment, the urease inhibitor could have helped reduce ammonia (NH3) volatilization in the dry spring period and the nitrification inhibitor may have reduced potential denitrification losses after heavy rains were received in mid-June. A final undergraduate thesis report will be available in the spring of 2010. SK-41