Extra N pays big in corn after corn
Results from Practical Research Plots conducted by Beck’s Hybrids show it pays to apply more nitrogen for corn after corn than many people previously thought. Six-year data gives the biggest indication of the need for extra N in corn after corn vs. corn after soybeans.
If N is 40 cents per pound and corn is $4.25 per bushel, optimum yield in corn after soybeans is just over 175 pounds per acre, Scott Ebelhor says. Ebelhor manages PFR plots at Ft. Branch. However, if N increases to 50 cents per pound, the optimum drops to just over 170 pounds per acre. At 60 cents per pound, the optimum rate falls between 165 and 170 pounds.
Corn after corn
The picture changes when you look at corn after corn, notes Scott Beck, vice president of Beck’s Hybrids. At 40-cent-per-pound N and $4.35-per-bushel corn, the optimum rate over the six-year average moves to just over 230 pounds per acre. At 50 cents per pound, it’s just over 225 pounds per acre, and at 60 cents per pound the optimum rate would be 220 pounds per acre.
The range is 168 to 176 pounds of N per acre after soybeans, and 220 to 232 pounds per acre after corn. Those are differences of just over 50 pounds per acre for comparative N prices. Many studies in the past have concluded that 30 to 40 pounds of additional N should be sufficient in corn-after-corn situations.
This article published in the January, 2011 edition of INDIANA PRAIRIE FARMER.