TRIAL OBJECTIVE
Nitrogen fertilization plays an important role in maximizing the yield potential of corn products.
Nitrogen is responsible for many soil fertility and crop nutrition studies with emphasis on finding the right rate, timing, source, and placement.
The objective of this study was to characterize the harvest intactness and yield potential of sixteen Kruger Seeds™ brand corn products to nitrogen fertilization. Nitrogen rates were selected to induce both nitrogen stress and excess nitrogen.
Such information can assist growers in making management decisions to help maximize profitability.
RESEARCH SITE DETAILS

- The nitrogen rate treatments tested in this trial included:
- Low: 30 lbs/acre for corn-soybean rotation or 50 lbs/acre for corn-corn rotation.
- Medium: 200 lbs/acre for corn-corn rotation (Huxley only).
- High: 230 lbs/acre for corn-soybean rotation or 240 lbs/acre for corn-corn rotation.
All nitrogen applications were made before planting.
Sixteen Kruger Seeds™ Brand Blend corn products were tested in this trial. Products were broken into an early maturity set (North set planted at Storm Lake and Huxley, Iowa) and a late maturity set (South set planted at Huxley and Atlantic, Iowa).
The North Set consisted of Kruger Seeds™ K9701SS Brand Blend, K9915DP Brand Blend, K0358SS Brand Blend, K0518DD Brand Blend, K0626DP Brand Blend, K0655SS Brand Blend, K4R-9706 Brand Blend, and K0708DT Brand Blend.
The South Set consisted of K0915DD Brand Blend, K0917SS Brand Blend, K1005DP Brand Blend, K1114SS Brand Blend, K1204SS Brand Blend, K1237DT Brand Blend, K1501DP Brand Blend, and K1541SS Brand Blend.
The trial was planted using 30-inch row spacing, with four rows per treatment, and 45-foot long plots with two replications.
The Huxley, Iowa site was in the path of the August 2020 derecho; therefore, yield data are not presented for this site.
UNDERSTANDING THE RESULTS
Figures 1 through 16 show the pictorial characterization of the ears of each product at the Huxley trial which had nitrogen rates of 50, 200, and 240 lbs/acre. Images were taken of representative ears for each plot prior to deterioration of the plot due to the derecho storm event.
At Atlantic and Storm Lake, Iowa, average grain yields were substantially higher for the high rate compared to the low rate with an average yield difference of 17 bu/acre at Storm Lake (Figure 17) and 74 bu/acre at Atlantic (Figure 18).


















KEY LEARNINGS
Nitrogen status in the soil is a dynamic and complex phenomenon that is greatly impacted by the weather during the growing season, the soil type and the inherent fertility of the soil. Thus, a plant’s response to nitrogen can be complex as well.
Even at low nitrogen rates, there was a yield average of 193 bu/acre and 186 bu/acre at Storm Lake and Atlantic, respectively. This indicates the fields were of high fertility and should be sustainably managed to avoid nitrogen loss to the water system.
At the current market trend of $0.34/lb of nitrogen and $4.00/bu for corn, a minimum of 17 bu/acre is required to pay for the difference between the low and high nitrogen rates. Therefore, at the Atlantic, Iowa location, all eight products were profitable. At the Storm Lake, Iowa location, the high nitrogen rate was profitable for three of the eight products (37.5%) tested.
Corn products respond differently to farm inputs and they should be assessed on a small scale before they are deployed for the whole farm.
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