The Role of Enhanced Efficiency Fertilizers in Fall and Spring Nitrogen Placement.

There are three major losses of nitrogen (N) from the soil-plant system, namely, volatilization, denitrification and leaching. There have been a number of practices recommended to reducing volatilization of urea-based fertilizers, e.g., use of urease inhibitors, slow-release forms, and, irrigation shortly after application. However, the most common practice in western Canada has been incorporation of the fertilizer into the soil, especially in bands. This practice now is under scrutiny, as shallow banding of urea-based fertilizers is proving to be less efficient in affording protection compared to deep banding. This study summarizes the data from a three-year research conducted in the three prairie provinces that included deep-, shallow-banded and broadcast urea with or without the addition of stabilizers. Agrotain^® stabilized urea (NBPT) and SuperU^® (NBPT and DCD) fertilizer were used (NBPT is a urease and DCD a nitrification inhibitor). Overall, there were no differences in yield when fertilizers were deep banded (6-8 cm); however, broadcasting or shallow banding (1-4 cm) non-stabilized urea resulted in significant yield reductions.