Effect of ESN Coated Urea Application Timing and Rate on Bermudagrass Yield in Mississippi.

In recent years many fertilizer enhancers commonly used in the row crop industry has transitioned into forage systems with the assumption that they will have equivalent effects. One such product is Agrium’s ESN (Environmentally Smart Nitrogen), a controlled release urea fertilizer. Limited research has been accomplished in Mississippi where warm wet summers are normal climate factors. Plots were arranged in a randomized complete block and dry matter (DM) yield data collected in 2013 and 2014. At the initiation of the study plots were amended with phosphorus and potash and pH ammended according to the Mississippi State University soil lab recommendations for bermudagrass production. The treatments included an untreated check, and applications of 100 lbs ac-1 of ESN + Urea, 100 lbs ac-1 of ESN + urea ammonium sulfate (UAS), 100 lbs ac-1 of ESN, 100 lbs ac-1 of Urea and 100 lbs ac-1 of UAS before the first and after second harvest. Additional treatments included 50 lbs ac-1 of Urea and 50 lbs ac-1 of UAS applied before the first and after the second, third, and fourth harvest. A year by treatment interaction was significant so years were analyzed individually. In 2013 total forage yield was affected by treatments similarly with the exception of ESN + urea which performed better than the control but less than the other treatments. Harvest yield was not effected by treatment by the September and October harvest. In July and August greater yields were achieved when 50 lbs ac-1 of urea and UAS were applied after each harvest. In the first harvest, treatments were similar to each other with the exception of the ESN + Urea application which produced less than the other treatments but more than the control. In 2014 total yields were similar among treatment except for ESN by itself and 100 lbs ac-1 of UAS which produced more than the control but less than the other treatments. In 2013 rains were consistent and temperature fairly moderate for Mississippi, explaining the relative consistency among treatments. However 2014 was characterized by several hot periods with little rainfall leading to more variable yield results among treatments but little significant data. The data does not conclude that ESN offers any advantage to forage DM yield in Mississippi especially when research compares to split applications of urea and UAS throughout the season. More research is warranted to identify trends from year to year.