Effects of enhanced efficiency fertilizers on cotton growth characteristics

Authors: Runion, George; Watts, Dexter

Submitted to: Crop Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/3/2014
Publication Date: 7/2/2014
Citation: Runion, G.B., Watts, D.B. 2014. Effects of enhanced efficiency fertilizers on cotton growth characteristics. Crop Management. 13(1):1-11. https://doi.org/10.2134/cm-2013-0050-RS.
DOI: https://doi.org/10.2134/cm-2013-0050-RS

Interpretive Summary: Enhanced efficiency N fertilizers (EENFs) are controlled and slow release N fertilizers whose use has generally been restricted to horticultural applications. These fertilizers are believed to increase N uptake in plants by synchronizing N release with plant growth and to reduce N losses to the environment. Recently, interest in their use in row crop agriculture has increased. Therefore, a three-year study was conducted to compare EENFs with traditional fertilizers in cotton. Nitrogen sources evaluated included urea, ammonium sulfate, urea-ammonium sulfate, a controlled release polymer coated urea (Environmentally Smart Nitrogen; ESN), stabilized urea containing a urease and a nitrification inhibitor (Super U), poultry litter, poultry litter + a urease and a nitrification inhibitor (AgrotainPlus), and an unfertilized control. Generally, traditional fertilizers resulted in the largest number of bolls and the highest boll dry weight. ESN tended to perform as well as the standards. Both poultry litter treatments performed poorly during the first year; however, poultry litter + AgrotainPlus was similar to the standard fertilizers by the third year. The more expensive EENFs were similar to standard fertilizers, suggesting they may be economically impractical at present. However, if EENFs reduce N loss from agricultural fields via leaching, runoff, and nitrous oxide flux, they could become viable alternative fertilizers.

Technical Abstract: The use of enhanced-efficiency N fertilizers (EENFs) in row crop agriculture has not been well studied despite increasing interest in these N sources to increase crop yield while also decreasing N loss. Therefore, a field study was conducted in Central Alabama from 2009 to 2011 to compare EENFs to standard N sources in a high-residue conservation cotton production system. Nitrogen fertilizer sources evaluated were: urea; ammonium sulfate; urea-ammonium sulfate; controlled-release, polymer-coated urea (ESN); stabilized urea (SuperU); poultry litter; poultry litter + AgrotainPlus; and an unfertilized control. Detailed plant growth characteristics were determined prior to defoliation. Generally, standard fertilizers resulted in the largest number of bolls and the highest boll dry weight. ESN tended to perform as well as the standards. Both poultry litter treatments performed poorly during the first year; however, poultry litter + AgrotainPlus was similar to the standards by the third year of study. In this study, the more expensive EENFs produced yields similar to standard fertilizers, suggesting they may be economically impractical at present. However, EENFs could become viable alternative fertilizer sources given their ability to reduce N loss from agricultural fields via leaching, runoff, and nitrous oxide flux. Additional research is needed on the benefits of EENFs in row crop production systems.