Evaluation of Phosphate and Nitrogen Fertilizers Treated with Polymer Additives to Increase Fertilizer Efficiency

This project consisted of two experiments (each at Ellerslie and Breton, Alberta) evaluating the effect of adding the Avail^® polymer to P fertilizers as well as a single experiment at Ellerslie which evaluated the effect of adding the Nutrisphere^® polymer to granular urea fertilizer. This study was initiated in April 2008 and it is planned to be repeated again in 2009.

In the P experiments, eight treatments compared two P fertilizer products [granular monoammonium phosphate (11-52-0) and liquid polyphosphate (10-34-0)], two P rates (15 and 30 kg P₂O₅/ha), and P fertilizer product with and without the Avail^® fertilizer additive. A check treatment (no P fertilizer) was included to determine the overall response to the addition of P. A modest response to P was observed at both sites. At Ellerslie there was a significant difference between the 30 and 15 kg P₂O₅/ha rates, yielding 94.6 and 85.6 bu/A, respectively. There was no observable difference between the two P fertilizer products, or whether Avail^® was added or not. At Breton, there was a significant difference between form of P with 10-34-0 averaging 26.6 bu/A compared to 11-52-0 averaging only 16.6 bu/A. There was no difference between rate of P, or whether or not Avail^® was added.

In the N experiment, a similar experimental design was used to compare four forms of N (urea, ESN^® or controlled release urea, Nutrisphere^®-treated urea, and Super Urea), two rates of N (60 or 120 kg N/ha), and two N placements including side-banded N placed 2 in. to the side of the seed row, and surface broadcast just prior to no-till seeding. A no-N check was included to determine if there was a response to N. Significant responses were found for N rate (46 and 41 bu/A respectively for 120 and 60 kg N/ha), and N placement (45.5 and 41.5 bu/A, respectively, for broadcast and banded N). No difference was noted between the forms of N fertilizer. AB-26F