Evaluation of Enhanced Efficiency Nitrogen Fertilizers for Cotton and Corn Production

Improving N use efficiency will increase profit margins and reduce potential negative impacts of transport of excessive N into surface and ground water. In response to these goals, several manufacturers have introduced enhanced efficiency N fertilizers where the N chemistry has been modified to prevent or reduce N loss from the crop rooting zone. Very little information is available on cotton response to enhanced efficiency N fertilizers in Arkansas. A replicated field experiment was conducted to evaluate cotton response to urea and an enhanced efficiency N fertilizer (marketed under the trade name of ESN) on a representative cotton producing soil of Arkansas. The study was arranged as a randomized complete block design with a factorial arrangement of urea and ESN where each source was preplant incorporated at five rates corresponding to 30, 60, 90, 120, and 150 lb N/acre. Additional treatments consisting of a check (0 N) and 60 lb N/acre from SuperU (incorporated pre plant or surface applied after planting) were also included. Effect of treatments on N concentration in the leaf blade at peak bloom and cotton yield were measured. Effect of selected treatments on cotton dry biomass production and N uptake were measured and cotton development was monitored using the COTMAN software program. The data will be analyzed to perform a preliminary assessment of enhanced efficiency N fertilizers for cotton production under soil and cropping conditions of Arkansas.