Nitrogen Fertility Effects on Grain Yield, Protein, and Oil of Corn Hybrids with Enhanced Grain Quality Traits

Grain of corn (Zea mays L.) hybrids containing nutritionally enhanced genetics may exhibit higher oil and crude protein profiles than normal field corn. However, the impact of N management on these traits is not well understood. Field experiments were conducted at Hoytville, OH from 2000 to 2002 to determine effects of different timings of nitrogen application (at planting versus split) and N rates (0, 60, 120, and 180 lb/acre) on the grain yield, protein, and oil of two corn hybrids containing Supercede genetics. Grain protein concentration showed more consistent response to increasing N rates than did yield. Protein exhibited a linear response to increasing N rates each year. Yield responded positively to increasing N rates in 2001 and 2002 but showed no additional response above 60 lb of N per acre in 2000. Split applications of N increased grain protein concentration in two of the three years, but had little or no effect on yield. Grain oil concentration was not influenced by the timing of N application and responded to N rate only in 2001. Results of the study demonstrate that N management will be an important factor in maximizing the grain protein of nutritionally enhanced hybrids, but producing grain with consistently high protein concentration may be difficult given the variation in growing conditions and environments characteristic of this part of the Corn Belt.