Large Urea Granules for Broadcast Application for No-till Cropping - University of Alberta, Ellerslie, AB

This experiment with related research at other locations is being done to compare the effectiveness of broadcast urea fertilizer compared to the common standard of side-banded urea at planting. There is a trend in some areas to use broadcast N applications in no-till or direct seeded cropping as a way to save time and speed up planting. To help reduce the chance of losses a few technologies are being evaluated. These technologies include the size of the urea granules and the addition of urease and nitrification inhibitors. Half the experimental treatments use regular-sized urea while half are forestry grade size granules approximately 11 mm (1/2 in.) diameter. The fourth year of the planned five years of research on this project went ahead as planned with the study planted to barley.

Initially, moisture conditions were on the dry side, but ample rains were received by mid May and continued through June and early July. After this little rain was received and warm temperatures were experienced through the rest of the summer and into early September when the site was harvested. Yields were quite high and harvest conditions were dry and completed on schedule. Unfortunately during the summer, the research site was next to a buried oil pipeline and one-quarter of the plots were lost due to pipeline maintenance work. Statistical analysis was done using analysis of variance with allowance made for missing plots. This however did reduce the chance to discriminate between experimental treatments. The ample moisture and warm temperature allowed significant mineralization of N from soil organic matter at the site, thus not giving as great a response to added N as in the previous two years. The only fertilizer treatment that yielded significantly better than the check or zero N treatment was the large urea treated with both a urease inhibitor (Agrotain®) and a nitrification inhibitor (N-Serve®). The yields were respectively 4.19 and 5.52 t/ha (78 and 102 bu/A). All other treatments were neither significantly better than the check treatments and not significantly lower than the highest yielding. Looking at the 2012 results, there does not seem to be any advantage or disadvantage to using the large urea granules. Research at this site will continue for one more year. AB-27