Tillage, Irrigation Scheduling and Nitrogen Effects On Corn Yield.

A field study was conducted in 2010 and 2011 near Imperial, NE to examine the effects of tillage, irrigation scheduling and nitrogen rate on corn yield.  The study was arranged in a  factorial design with four replications in 2010 and six replications in 2011.  A split-block, split-plot design was utilized with blocks split on tillage treatment and plots split on irrigation treatment.  Irrigation treatments consisted of deficit irrigation, low capacity irrigation, Watermiser and fully irrigated (100% ET replacement).  Irrigation treatments were controlled by a variable rate irrigation system (FarmScan).  Nitrogen rates of 150, 200 and 250 lb N/acre, were applied using urea (46-0-0).  Nitrogen treatments were nested within each irrigation plot.  Tillage treatments consisted of no-till and conventional-till (disked twice).  Yields were greater in the conventional-till treatments than in the no-till treatments.  Yield was greatest in the low capacity treatment, but was not different from the fully irrigated treatment.  There were no differences in yield in response to nitrogen treatment.