Effect of Urease – Nitrification Inhibitors on Cotton Yield, Fiber Quality and Growth

Ongoing volatility in the fertilizer market place accentuates the need for careful management of nitrogen (N) fertility for cotton production.  Increasing concerns regarding nutrient contamination of surface and groundwater resources have refocused attention on N management in cotton and other crops.  Properly managed, slow-release N fertilizers have the potential to improve N use efficiency in cotton and thus reduce N losses to water resources.  A field study was initiated in a river bottom soil with a moderate residual N level as determined by soil sampling to 12 inches.  Fertility treatments included a control or 0 N added and 60 or 80 pounds of N per acre added using liquid urea ammonium nitrate (UAN) alone or in combination with two urease, nitrification inhibitor products subsurface-band applied at the second true leaf stage.  An additional treatment included the application of 30 pounds N per acre subsurface-band applied at second true leaf then 50 pounds of N per acre applied at pinhead square.  Experimental units were arranged in a randomized complete block design and replicated five times.  Notes on maturity and growth were collected during the season.  Lint yield and fiber quality were collected at harvest.