Longevities of Single Application of Urea Types of Fertilizers On Bermudagrass Fairway Turf.

Nitrogen is the mineral nutrient that plants require the most.  Comprising 3-6% of the dry weight of turfgrass, nitrogen is a vital component of chlorophyll, amino acids, proteins, nucleic acids and secondary metabolites.  Due to this fact, nitrogen is often applied in the greatest amounts in turfgrass management programs among all the nutrients applied.   However, over fertilization and inefficient delivery of nitrogen are problems that can lead to negative environmental impacts.  This study examined several coated urea fertilizers to determine their longevity throughout the growing season.  The treatments include: Control (0 kg N ha^-1yr^-1), Urea, Urea+Nutrisphere, Sulfur Coated Urea, and Polyon at 49, 98, and 196 kg N ha^-1 only applied once on the same day of April 15 in 2009 and 2010 at two different study sites of Tifway bermudagrass (Cynodon dactylon (L.) Pers. X C. transvaalensis Burtt-Davy) fairway conditions in Clemson, SC.  After application, a light irrigation was applied to minimize potential losses due to volatilization.  The experimental design was randomized complete block design with four replications with plots mowed at 13 mm maintained as a fairway turf.  Parameters were measured throughout the growing season and included: weekly turf quality, monthly clipping yield and monthly clipping nutrient analyses.  The results show significant differences in turf quality in April and May and clipping nitrogen concentrations were kept high till July in 2009 and 2010.  All controlled release nitrogen sources demonstrated longer effects than urea.  However, the nitrogen fate and volatilization rates were not measured and these are needed for the future studies.