Although advances in agronomy, breeding, and biotechnology have dramatically increased corn grain yields, soil test values indicate that producers may not be supplying optimal nutrient levels. Moreover, many current nutrient recommendations, developed decades ago using outdated agronomic management practices and lower-yielding, non-transgenic hybrids, may need adjusting.
Researchers with the University of Illinois Crop Physiology Laboratory have been re-evaluating nutrient uptake and partitioning in modern corn hybrids. "Current fertilization practices may not match the uptake capabilities of hybrids that contain transgenic insect protection and that are grown at planting densities that increase by about 400 plants per acre per year," said U of I Ph.D. student Ross Bender. "Nutrient recommendations may not be calibrated to modern, higher-yielding genetics and management." ...
"Although macro- and micronutrients are both essential for plant growth and development, two major aspects of plant nutrition are important to better determine which nutrients require the greatest attention: the amount of a nutrient needed for production, or total uptake, and the amount of that nutrient that accumulates in the grain."
Study results indicated that high amounts of nitrogen (N), potassium (K), P, and S are needed, with applications made during key growth stages to maximize crop growth. Moreover, adequately accounting for nutrients with high harvest index values the proportion of total nutrient uptake present in corn grain), such as N, P, S, and Zn, which are removed from production fields via the grain, is vital to maintaining long-term soil productivity...
"Although nutrient management is a complex process, a greater understanding of the physiology of nutrient accumulation and utilization is critical to maximize the inherent yield potential of corn," concluded Bender.
Original study: http://dx.doi.org/10.2134/agronj2012.0352
Via Alexander J. Stein