Response of Corn Hybrids to Nitrogen Fertilizer

Abstract

Current economic pressure, combined with growing public concern over nitrates in groundwater, has resulted in increased interest in managing N fertilizer in corn (Zea mays L.) production. The response of modern corn hybrids to N in a number of different field environments was investigated. Twelve elite hybrids were grown in 13 field environments and a number of other hybrids were evaluated in five additional environments. All locations were in the U.S. Corn Belt. Results indicated a statistically significant response of corn hybrid yield to N. The hybrids differed in average yield, however no consistent hybrid × N rate interaction was found in any of the experiments. This indicates that the hybrids responded to N in a similar way when averaged across the environments. While there may be differences in hybrid response in a particular type of environment, responses were not predictable across different weather patterns and soil types. Agronomic traits and leaf N were also measured and are discussed. Based on these findings, farmers should manage their N program in a similar manner for all hybrids, by efficiently applying an optimal rate of N and minimizing the possibility of nitrates leaching into groundwater.