Enhanced Efficiency N Products On Corn Production Systems in the the Lower Mid-South.

Nitrogen is the most yield limiting agricultural input in irrigated, non-leguminous production systems.  This is especially true in Mid-South corn systems due to the high N demand as well as the high N loss potential.  As a result of the high corn N demand and the increased loss potential, proper N management should focus on not only optimum production but also increased N use efficiency (NUE).  The use of enhanced efficiency N fertilizers (EENF) can potentially achieve both of these tasks by decreasing loss mechanisms and therefore potentially enhancing uptake efficiency.  While these products have been available for decades, limited research has directly compared the active chemicals of these EENF in corn production in the Mid-South, especially over N rates.  Therefore, a study was initiated in 2013 at three locations in the Mid South, two sites in Louisiana and the other in Mississippi.  Due to environmental conditions, the Mississippi location was terminated for the 2013 season.  The study was laid out in a randomized complete block design with six replications.  Factors included six different EENF and three different N rates.  Yield was significantly influenced by both N rate and EENF source.  However, there was no significant interaction between product and N rate for either location.  This indicated that the application of EENF did not influence optimum N rate.  However, the application of products that inhibited the major loss mechanism for each location (volatilization for the upland and nitrate losses for the alluvial) significantly improved corn grain yield.