THE EFFECT OF AT-PLANTING NITROGEN APPLICATION RATES ON NO-TILL CORN YIELD
Agronomy & Pest Management
Wayne Flanary
Field Specialist in Agronomy
University of Missouri Extension
St. Joseph
Abstract
The optimum corn nitrogen application rate varies from year to year as environmental conditions such as soil moisture impact crop yields. The objective of these experiments was to demonstrate to growers that optimum nitrogen rates vary from year to year. Nitrogen fertilizer was applied as ammonium nitrate at a rate of 0, 60, 120, 180, 240 and 300 pounds of actual nitrogen per acre. The ammonium nitrate nitrogen was surface applied at planting on no-till corn following soybean. Seven years of data are summarized showing the optimum rate varied from year to year. One year, 2011 had the highest nitrogen efficiency producing over 200 bushels of corn with 120 pounds of actual nitrogen per acre. The years of 2005 and 2006 also produced approximately 200 bushels per acre with 180 pounds of nitrogen applied. Years 2007 and 2008 required 240 pounds of nitrogen to grow approximately 200 bushels of corn per acre. Next, the year of 2009 had the highest yields in the plots producing over 250 bushels of corn per acre with 300 pounds of nitrogen. Also 2010 maximized yields with 300 pounds of nitrogen per acre. Corn yields were maximized within a range from 120 to 300 pounds of nitrogen per acre depending on the year.
Authors: Flanary, W.
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Flanary, W. Agronomy Specialist, University of Missouri Extension, Missouri, 64473