Optimizing Nitrogen Management for Processing Sweet Corn Production on Fine-Textured Soils
Study author(s): Carl Rosen, University of Minnesota, Department of Soil, Water, and Climate
Years active: 2014-2017
Location(s): Waseca, MN
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summary
Our yield results suggest that the optimal N application rate for non-irrigated sweet corn following soybean on soils high in organic matter is in the range of 120 to 180 lbs N/ac, substantially higher than the currently recommended 110 lbs N/ac. The hybrids used in this study did not differ in their yield or N use responses to N treatment, contrary to our expectations. We found almost no effect of applying N as ESN preplant or in split applications of urea instead of a single preplant urea application, except for a decrease in the percentage of tissue N incorporated into the stover (equivalently, an increase in the percentage incorporated into the ears). In plots receiving at least 120 lbs N/ac, the stover had C:N ratios of 32:1 to 35:1. These relatively low ratios and the large amount of N left in the stover (from 70 to 77 lbs N/ac in the treatments receiving at least 120 lbs N/ac) suggest that there may be an N credit for field corn following sweet corn.