Grant: Collaborative Research and Development Grants

The overall objective of this study is to reduce ammonia volatilization losses from urea-based nitrogen (N) fertilizers and bridge the efficiency gap between fall and spring applied N fertilizer. Active AgriProducts (AAP) is in the process of developing a novel urease inhibitor (ARM-U) that takes into consideration some of the weaknesses of existing products. The company has evaluated the efficacy of ARM-U in the greenhouse and in the field. The results from the field and the greenhouse showed that ARM-U was as effective as commercial urease inhibitor in reducing ammonia volatilization from urea-based fertilizers. This study will further evaluate some of the unique characteristics of ARM-U, especially its low temperature fluidity and superior particle coverage by examining the potential of ARM-U and other existing commercial urease inhibitors to bridge the efficiency gap between fall and spring applied N fertilizer. Previous studies have shown that N fertilizer applied in the fall is only 80% as efficient as that applied in the spring. Nevertheless, farmers prefer to apply fertilizers in the fall because fertilizers are cheaper and fall application makes for better time management in the spring. Since we have shown that urease inhibitors in general, and ARM-U in particular, were effective in reducing ammonia volatilization in the greenhouse and in the field, these inhibitors may also be an effective technology for reducing the efficiency gap between fall and spring applied N fertilizers. The study will be carried out by a graduate student with help from a technician and a summer student in the field and in the laboratory as part of a doctoral thesis research. The study will confirm if low temperature fluidity and increased particle coverage improves the efficacy of fall applied urease inhibitors. It will also determine yield and N uptake responses of wheat and canola to urease inhibitors applied in the fall and spring. Our ability to provide information on the effect of low fall temperature on the efficacy of urease inhibitors and their ability to bridge the efficiency gap will be a win-win situation for farmers who can apply their fertilizers in the fall, without suffering any yield penalty. This will provide both economic and environmental benefits to Canadian farmers.*