Large Urea Granules for Broadcast Application for No-till Cropping in Alberta Spring Wheat

This summary reports the second of the planned three years of research. The growing season was more moist (234 mm compared to a long-term average of 198 mm) and slightly warmer (1,442 heat units, 30% more than average cool season crop heat units of 1,400). Unfortunately, the more moist and warm season resulted in greater than normal mineralization of N from soil organic matter and there was no yield response to added N fertilizer. Statistical analysis of the experimental factors of timing, size of urea granules, and the addition of urease and nitrification inhibitors was only significant for timing.

The fall applied treatments had an average yield of 2.7 t/ha (40 bu/A) compared to 2.4 t/ha (36 bu/A) for the spring applied treatments, with a least significant difference of 168 kg/ha (2.5 bu/A). The majority of spring wheat crops grown in this region are planted on no-till or chemical fallow. More moist and warmer weather conditions make it challenging to have a yield response to added N. It is planned next year to expand the research of this experiment to also include a winter wheat experiment that will be planted into stubble from the 2012 spring wheat crop. This will be in addition to the regular spring wheat planted into the chemical fallow. AB-29