If you are ever going to see differences for timing of nitrogen applications closer to when the plant needed it, you would think it would be this year in Indiana. After all, excessive rains pounded central Indiana during a good part of June and July.
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That included Ken Simpson's field near Morristown in Shelby County. This is the third straight year that Simpson has cooperated with Scott Gabbard, Shelby County Extension ag educator, and Purdue Extension specialists Bob Nielsen and Jim Camberato to do large-scale field trials on his farm.
"We established that the optimum economic nitrogen rate on this farm is about 210 pounds of N per acre after two years of testing," Nielsen says. "So we decided to test timing this year instead. Ken has always had an interest in split-applications. He thinks they should provide better results."
During the first two years of the trial, they included a split application in the rate trial. It did not provide an advantage in either of the two years it was tested.
This year they have 200 pounds of N going on at different times after planting in different combinations, up to the 15-leaf stage. Simpson can make the applications because he has a high-clearance Hagie sprayer with a bar for making N applications.
"So far just by looking we can't see any visual differences in the treatments," Nielsen says. "We really would expect to see treatments where the N was put on earlier not do as well because we would have thought more N would have been lost. It hasn't shown up to the naked eye yet."
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Nielsen, notes, however, that the final arbitrator will be the combine and yield monitor. Until you actually run the corn, just looking or even taking ear samples and running yield estimates is inconclusive. Look for results after the season.