The study was set up as a split-plot with irrigation environment as the whole plot and nitrogen management as the sub plot with three replications.
A 111 RM Brand Blend Corn product was planted.
Four different irrigation environments, via a sub-surface drip irrigation system, were used:
—Dryland – no supplemental irrigation
— 100% Full Irrigation (FI) – irrigated to meet the evapotranspiration needs of the crop (3 inches)
—50% FI – half the amount of irrigation applied over the growing season (1.5 inches)
— V14 to R2 (corn growth stage) – 100% FI applied between the V14 to R2 growth stages with no irrigation for the remainder of the growing season (1 inch)
— Zero N – no additional N applied
— Low N – 30 lb/acre of N applied preseason and 30 lb/acre applied at V9 (6/22/18)
— Medium N – 60 lb/acre of N applied preseason and 60 lb/acre applied at V9
— Medium Upfront – 120 lb/acre of N applied preseason
— Moderate N - 120 lb/acre of N applied preseason and 60 lb/acre applied at V8
— High N - 120 lb/acre of N applied preseason and 120 lb/acre applied at V8
There was no significant interaction of the irrigation environment with the nitrogen management strategy on yield but there was an interaction for test weight as recorded in Table 1.
For a majority of the nitrogen management treatments, higher test weights were observed when the crop was only irrigated from V14 to R2, with the exception of the Medium N treatment where test weight was higher for the 50% FI environment (Table 1).
The 100% FI treatment had the highest yield with next highest yield recorded with the targeted FI during the V14 to R2 growth stage (Figure 1).
The irrigation environment did not impact how nitrogen was used by the corn crop.
Producers should choose the nitrogen management system that works best for their operation.