Managing Global Resources for a Secure Future

Best management practice for granular urea placement for growing canola on the Canadian Prairies is banding to depths greater than 3”. Recently, growers are adopting shallow banding or surface placement to cover more area and at great nitrogen application rates. A three year study with two replicate plot trials in each year was conducted to examine the effect of placement (surface, and shallow 1” and deep 3” banding) and urea source (urea, Agrotain treated urea, and SuperU). Soil test recommended nitrogen additions rates for each trial varied from 80 to 129 kg N/ha. A 70% of recommended addition rate was also included to determine improvement in fertilizer use efficiency with treatments. Canola oilseed yield, growing season loses of nitrous oxide (N2O), qualitative emissions of ammonia (NH3), and extractable available nitrogen in soil were determined. Across all sites, yield was lower for surface placement than subsurface banding regardless of nitrogen source. Nitrous oxide emissions tended to be lowest for deep band placement in wet site years with SuperU having lower emissions than urea. Ammonia emissions were similar to the Control (0 N) for shallow and deep banded treatments but higher for surface placement. Ammonia loses were reduced with SuperU compared to urea when place on the soil surface.