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

Large and regular sized urea applied with and without urease and nitrification inhibitors, surface applied in fall or spring under no-till cropping.

IPNI-2009-CAN-AB27

03 Mar 2012

2011 Annual Interpretive Summary


This is the third year of an experimental study that 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, which 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, 2011. The 2011 growing season was very wet and cool during May, but warmed up for June, July and August. Moisture was adequate, but not excessive precipitation. Barley was harvested on September 8, 2011.

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, yielded similarly to the common farm practice of side-banding urea during planting. The side-banding treatment yielded an average of 73 bu/A. This site experiment had excessive spatial variability with a coefficient of variance (CV) of 20.3%. There was an overall response to added N with the control or zero-N treatment yielding only 65 bu/A, while some of the N treatments yielded up to 90 bu/A. It is planned to continue this experiment for one more growing season. AB-27