Blending ESN with Urea to Improve Nitrogen Efficiency in Soft Red Winter Wheat.

Under certain conditions, it has been reported that winter wheat has yielded less than other N sources from a single broadcast spring application. It has been hypothesized that ESN would be more effective blended with urea, particularly during abnormally colder conditions. The objective of this study was to evaluate blends of ESN and urea as a nitrogen source for wheat production in Ohio. In Fall 2008 and 2009, medium-maturity variety ‘Hopewell’ was established into soybean stubble on the OARDC North Central, Northwest, and Western Research Stations. Treatments included Urea, ESN, 75:25 urea:ESN blend, 50:50 urea:ESN blend, and a 25:75 urea:ESN blend. A nitrogen rate of 80 pounds per acre was applied at Feekes GS 3 and 6 for each treatment. Experimental design was a completely randomized block replicated four times. Analysis was a two factored ANOVA. Grain yield, test weight, spike number, and N uptake were measured for each treatment. Significant differences were observed among treatments for yield. ESN yields were significantly less than urea and the 75:25 and 50:50 urea:ESN blends. At Feekes GS 3, yields were similar among 75:25 urea:ESN, 50:50 urea:ESN blends and urea and  were similar between the 25:75 urea:ESN blend and ESN. Results were the same for the Feekes GS  6 application except the 50:50 urea:ESN blend was similar to ESN for yield.  ESN efficiency may be improved in soft red winter wheat by using urea as a blend for 25 to 50 % of the total N rate for early spring applications and 75% of the total N rate for Feekes GS 6 applications.