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

This project consisted of two experiments, one at Willingdon, Alberta comparing P fertilizer sources; and another at Dapp, Alberta comparing N fertilizer sources. This study was initiated in April 2008 making this the fourth year of experiments conducted by the University of Alberta.

In the P experiments, 13 treatments compared two P fertilizer products [granular monoammonium phosphate (11-52-0) and liquid polyphosphate (10-34-0)], three P rates (9, 18 and 27 lb P₂O₅/A), 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. Unfortunately, there appeared to be no response to P at the site, and because of adverse cool and excessive moisture conditions affecting germination and seedling establishment. There was no observable difference between the two P fertilizer products, rate of P, and whether Avail^® was added or not.

In the N experiment, an experimental design was used to compare three forms of N (urea, ESN^® urea, and Nutrisphere^®-treated urea), and four rates of N (22, 44, 88 and 132 lb N/A). All N fertilizer was side-banded at planting. A check or zero N treatment was included in each replicate to assess N response. The coefficient of variation (CV) was high for the site, i.e. 24.5%, due to uneven flooding adversely affecting plant stands over the plot area. There was a moderate response to N observed with the 88 and 132 lb N/a rates significantly out yielding the zero N treatment average. There was no difference between the 88 and 132 lb N/A rates due to lodging in the plots of the 132 lb N/A rate. There was no observable difference between N forms except at the 88 lb N/A rate where ESN and Nutrisphere N resulted in higher yields compared to regular urea. AB-26F