Fertilizer Nitrogen Stabilizer Effects on Corn Grrowth and Nitrogen Use.

Urea based fertilizers are susceptible to N losses through volatilization, denitrification, and leaching.  These losses can cause reduced N use efficiency and environmental pollution. A field study was conducted during 2013 and 2014 at Mississippi State, MS to determine the effects of N fertilizer stabilizers on corn (Zea mays L.) response to urea ammonium nitrate (UAN) solution and granular urea.  Comparisons between a standard UAN split application and a single application with and without N stabilization products were assessed to determine effects on N use efficiency and grain yield. Treatments included: untreated check, UAN split (50/50), single applications of UAN untreated, UAN plus urease inhibitor (UI), UAN plus nitrification inhibitor (NI), UAN plus UI and NI, untreated urea, and urea plus UI. Stabilization products were applied at labeled recommended rates for an N rate of 179.2 kg ha^-1. Chlorophyll and ear leaf N % at tasselling, N content at black layer, and grain yield were measured. The 2 y average indicated UAN with UI and NI had the greatest chlorophyll index (55) and grain yield at 11.8 Mg ha^-1. A single UAN application resulted in leaf N of 2.9% at tasselling. Apparent N recovery was 93.4% for UAN plus UI and 80.4% for urea plus UI. Treatments containing fertilizer N stabilizers did not significantly increase chlorophyll content, leaf N concentration, or grain yield compared to a split or single UAN application. Urea plus UI significantly increased leaf N concentrations. Greater N uptake did not increase grain yield.