Conventional wisdom is that if a low area in a field that isn’t drained well drowns out once, you might replant it. If it drowns out again, you might let it sit the year out. The farmer who tended the Corn Watch ’17 field is glad he didn’t subscribe to that thinking. Instead, he planted a third time after the first two plantings were ponded by heavy rains.

The two areas of the field that were replanted twice amounted to about an acre each. But they make a point worth observing. That is the whole concept behind Corn Watch ‘17, sponsored by Seed Genetics-Direct, Washington Court House, Ohio. The idea is to learn from what happens in the Corn Watch field during the season, and apply it to your decision-making process for 2018.

Both areas were yellow and only a few inches tall when the original planting was nearing tasseling at the end of June. Yet when the combine went through the field, yield was above 150 bushels per acre in one of the two spots, and just under 150 bushels in the other spot.

The farmer concluded that replanting those two areas the second time helped add to the field’s overall yield. Otherwise, they would have been blank spots on the yield monitor and would not have contributed to average yield.

Observations
Dave Nanda, an independent crops consultant based in Indianapolis, is surprised those areas performed as well as they did. “The ears tended to be smaller, and there were signs of nitrogen deficiency, but they certainly performed much better than you would have expected when looking at the area in late June.”

What did the third planting have going against it? First, the ground was so hard from ponding and beating rains that even at harvest, there were still large cracks present, forming a mosaic pattern. That was likely an indication that the soil was compacted, at least on the surface.

CRACKS TELL THE STORY: Corn yielded 150 bushels per acre in this spot even though it ponded numerous times and was planted a third time.

Second, some plants obviously ran short on nitrogen. In this case, the grower applied 180 pounds of anhydrous ammonia preplant. He did not add extra N to the spots where he planted a third time. The crop made what it did based on the nitrogen it obtained from the soil.

NEED NITROGEN: Several plants in this spot that was planted three times indicated they were in need of nitrogen late in the season.

That leads to two observations that Jim Camberato, Purdue University Extension soil fertility specialist, has made in the past. First, even when no N is applied, such as in a nitrogen trial, yield on silt loam soils can still reach and exceed 100 bushels per acre. This soil is a dark silt loam soil, which would be very productive if naturally drained or in years when excessive rain and ponding isn’t an issue.

Second, Camberato noted earlier this year that he has seen surprising results from late additions of N on corn where ponding and nitrogen loss occurred earlier in the year, assuming the plants are still healthy once the ponding ends.

There is no way to know in this case if the third planting would have responded even better if more N had been applied. However, Camberato says he has seen it happen in other situations.