Nutrient Sufficiency Concepts for Modern Corn Hybrids: Impacts of Management Practices and Yield Levels

Over the last 70 years, national corn yield gains have occurred because of superior genetic yield potentials and management improvements such as improved water management, higher plant densities, and earlier planting dates. Some management recommendations, such as those from seed companies that promote optimum plant densities, are often environment, hybrid, and/or yield-range specific. Nitrogen rate recommendations for corn are updated annually in the Corn Belt states and are sometimes adjusted for regions or soil zones within a state. In contrast, nutrient guidelines for nutrients other than N are assumed to be constant per unit of yield produced, and have generally not been updated in key corn-producing states. Some recent studies providing nutrient content values for corn grain and/or stover did not account for management practices and yield levels for which nutrient replacement recommendations would be pertinent. The purpose of this report is to illustrate how macroand micronutrient contents for modern corn hybrids can change in the context of diverse plant densities, N rates, and accompanying yield range influences in certain environments. The information presented here can be used to better understand nutrient content and removal for more precisely implementing best nutrient management practices for current corn hybrids at diverse yield ranges. Optimum nutrient management (recently popularized as using the “4Rs” approach involving selection of right rate, time, placement and source [IPNI, 2012]) should be pursued to increase corn yields in a sustainable manner. Current nutrient management decisions for nutrients other than N are typically based on publicly available information that may be more pertinent for corn hybrids and management in earlier decades (Chandler, 1960; Hanway, 1962a, 1962b; Jordan et al., 1950; Karlen et al., 1987, 1988; Sayre, 1948), although there have been some more recent recommendations for specific nutrients (Bundy, 2004; Fernández, 2012; Sawyer and Mallarino, 2007). Total plant nutrient content or grain nutrient removal calculations are now based on constant nutrient concentration Published in Crop Management DOI 10.2134/CM-2013-0022-RS © 2014 American Society of Agronomy and Crop Science Society of America 5585 Guilford Rd., Madison, WI 53711 All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Permission for printing and for reprinting the material contained herein has been obtained by the publisher. I.A. Ciampitti, Dep. of Agronomy, Kansas State Univ., Manhattan, KS 66506, and T.J. Vyn, Agronomy Dep., Purdue Univ., West Lafayette, IN 47906. Received 18 Sept. 2013. *Corresponding author ([email protected]).