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

This experimental study was initiated to evaluate the potential use of two technologies for broadcast urea granules prior to no-till planting of small grain cereals in the Northern Great Plains region of North America. This is seen as a possibility to allow N application with less energy required during planting compared to banding N at planting. The two technologies being evaluated are: 1) the size of the urea granules, comparing regular size granules (approximately 3 mm, or 1/8 in.) to large forestry grade granules (approximately 10 mm or 1/2 in.); and 2) adding urease inhibitor, and or a urease plus nitrification inhibitor to the granules. One additional experimental factor is the timing of application, that being in the mid-fall, compared to early spring, and at planting. There are two control treatments included in the study. One is a zero N treatment in order to determine the N response at the site, and the other is a common farmer practice of side-banding N fertilizer during the planting operation, or so-called “double-shoot planting”. All rates of N were 62 lb N/A, which is sub-optimal, but chosen to hopefully show potential differences between experimental factors. The research experiment was conducted at the University of Alberta (AB) Research Farm at Ellerslie, AB. Spring barley was no-till planted on April, 27. The growing season was favorable to growth with adequate, but not excessive precipitation. Barley was harvested on August 30, 2010.

The three hypotheses of the study were: 1) that spring applications would out-yield fall applications; 2) that the large granules would out-yield the regular size granules; and 3) that the addition of urease, or urease plus nitrification inhibitors would out-yield regular untreated urea. However, results show little differences between experimental factors. All the broadcast urea treatments with large or regular sized granules; and with or without addition of an urease inhibitor; or an urease inhibitor plus a nitrification inhibitor, out-yielded the common farm practice of side-banding urea during planting. The side-banding treatment yielded an average of 88 bu/A. Additionally there was an excellent response to added N with the control or zero-N treatment yielding only 58 bu/A, while all broadcast N treatments averaged between 95 and 108 bu/A. It is planned to continue this experiment for two more growing seasons. AB-27