ARS | Publication request: Alternative Nitrogen Sources for Cotton

Submitted to: Cotton Research and Extension Report
Publication Type: Experiment Station
Publication Acceptance Date: February 15, 2009
Publication Date: March 15, 2009
Citation: Mitchell, C.C., Balkcom, K.S., Burmester, C.H. 2009. Alternative Nitrogen Sources for Cotton. 2008 Cotton Research and Extension Report. No.33. p. 34.

Technical Abstract: Several alternative nitrogen (N) sources, rates of N, and amendments were evaluated at Prattville, Alabama, on cotton in 2008. Nitrogen rates reported are for sidedress application only. Dry urea produced the highest yield, averaging 1100 pounds lint per acre. Ammonia volatilization was measured from selected topdress N materials for two weeks after they were applied on July 8, 2008. A commercially available, controlled-release N material, Nitamin Nfusion®, was included in the study. This material is recommended to be applied with liquid N or some other readily available N source, but we used it as a topdress N application. All plots except the no-N plots received 40 pounds N at planting. Loss of urea from volatilization was also very low for dry urea, less than 5 pounds N per acre out of 80 pounds applied over a two-week period. Ammonia loss from liquid UAN solutions was the highest (20 pounds N per acre out of 80 applied). Dry urea likely dropped below the rolled rye cover crop residue whereas broadcast UAN solution was sprayed on top of the rye residue. Agrotain® (AG) appeared to reduce volatilization losses from urea but not from the UAN solution, but the results were erratic.