Longevity of Turf Response to Urea, Coated Urea, and Blends – 2012 trial

The objective of this research project was to quantify turf response to a one-time application of urea-based fertilizers on Kentucky bluegrass turf on a soil rootzone. The longevity of turf when treated with urea, coated urea, and various blends was analyzed. Turf performance was assessed through visual ratings for colour, quality, density, and uniformity as well as through the use of a normalized-difference vegetation index (NDVI). Growth of shoots was measured through dry weights of clipping collections taken periodically throughout the experiment.All treatments gave a significant improvement in colour and growth compared to the untreated control. The fertilizer effects were observable within a week after treatment by the canopy reflectance data, and persisted in significant amounts until more than 10 weeks after treatment. The average gain of fertilized treatments over control was at least 2 ranks on the visual colour rating scale (6 to 8), or about 0.07 units on the NDVI. There were significant treatments differences in both strength of response and days to maximum release. The release across all treatments was stronger and slower in 2012 than in 2011. The pattern observed in 2012 was very different than the pattern observed in 2011. Agrium Advanced Technologies