ESN as a Fall Nitrogen Source for Corn.

Anhydrous ammonia with a nitrification inhibitor is the only acceptable fall N program for corn in the Eastern Corn Belt. ESN may be an alternative program. To test this hypothesis, ESN, urea, and anhydrous ammonia plus a nitrification inhibitor were fall applied in 2005 and 2006 on a clay soil at the OARDC Northwest Research Station near Custar, OH. ESN and urea were incorporated soon after surface application. Fertilizers were applied at three N rates. Same treatments were repeated in the spring prior to planting. Experimental design was a three factor randomized block with four replications. Yields were similar between fall and spring applications for both years. In 2006, yields were similar among N sources regardless of application time. In 2007, fall applied urea yielded less than fall applied ESN or anhydrous ammonia and spring applied ESN yielded less than spring applied anhydrous ammonia or urea. Yields from fall applied ESN were similar to anhydrous ammonia plus a nitrification inhibitor for both years and may be an alternative fall program. However, ESN yields were less than anhydrous ammonia for spring applications in 2007, which may have been affected by abnormally dry conditions during the first half of the growing season.