Evaluation of Three New Nitrogen Fertilizers On Yield and Nitrogen Efficiency in Winter Wheat and Corn.

As the human population grows and expands, increasing pressure is applied to cropland for food production. To meet this demand, fertilizer products are being developed and marketed with the potential to increase yields and nutrient efficiency. Three such products being marketed in the southeastern US are Nutrisphere™, ESN®, and UCAN-23™. We undertook a study to compare these new, synthetic nitrogen (N) fertilizers with aqueous urea-ammonium nitrate (UAN) [(NH₂)₂CO, NH₄NO₃] during a two-year field experiment. Maize and winter wheat were grown on soils in the three physiographic regions of North Carolina (NC). Treatments were fertilizer source and fertilizer rate. Wheat nitrogen use efficiency (NUE) only reached 50% across all treatments and rates on a fine sandy loam soil, while it ranged from 8-31% on loamy sand. Wheat yield differences were only observed at one of two sites, where the ESN fertilizer yield was statistically lower than the others across three of the four fertilizer rates. The corn trials did not show any yield differences between treatments. These results were likely influenced by the extremely droughty weather experienced in NC in 2008. An aerobic incubation experiment was also performed to evaluate the N release profiles of the fertilizers under corn growing conditions. Laboratory incubation data suggests that Nutrisphere and UCAN performed similarly to UAN, while ESN showed a slower release profile under corn growing conditions. One more year of field data is needed to reach solid conclusions on the performance of these fertilizer products.