Don’t Make a Late Start to Corn Planting Even Worse
Chad Lee, University of Kentucky
The calendar says that farmers in western and southern Kentucky should be planting corn. The weather says something very different right now. At some point, the temperatures will increase and the soils will dry. The challenge will be to not rush into planting and sets yourselves back even farther.
Recently a golfer who won a major championship last year was playing the first round of the same tournament this year. He hit a ball right on the green, very close to the hole. Then it rolled backwards and into the water. So, he tried it, again. It landed on the green and then rolled into the water. Now, realizing that he was behind, he felt the urge to catch up. Instead of taking the safe route, he tried again. And, again it hit the green and rolled into the water. He tried once more, only to have it hit the green… and roll into the water. Finally, he took the penalty drop. On the first day of the tournament, at one hole, his championship run ended before he really got started.
Farmers run that same risk this spring planting corn.
The weather has pushed corn planting late on the calendar. We all know that. Farmers already feel behind. According to the calendar, they are behind. But, according to the weather, they are early. Farmers need to pay attention to the conditions and not the calendar when planting corn this season.
Pushing corn planting could lead to uneven stands, poor emergence, delayed emergence and sidewall compaction. All of these factors will push the crop farther behind and snatch away a winning season before it really gets started.
Cool soils can delay emergence. The best down pressure adjustments, seed placements, depth controls, insecticides, fungicides and seed quality cannot overcome cold temperatures. Dropping the day/night temperatures from 77 and 59 F to 68 and 50 F delayed corn emergence by 10 days! I will repeat that in case you read it too quickly. Dropping temperatures by about 9 degrees slowed corn emergence by 10 days. TEN DAYS! High seed vigor and seed treatments did not overcome the cold temperatures. That delay in emergence also decreased uniformity of emergence. That lack of uniformity in emergence can result in yield losses.
Every farmer knows that getting into a field one day too soon causes the most soil compaction. This is true with planting equipment as well. Adjustable down pressure units are supposed to help with this problem, but those units will not prevent all sidewall compaction. Some farmers may be tempted to do some tillage to “dry out” the soil surface. The same risk holds. Working that field one day too soon will cause compaction at the tillage depth. Disks are the worst at making compaction. However, I have observed compaction from “vertical tillage” implements as well. Sidewall compaction and subsurface soil compaction will stunt corn roots. Those stunted roots will cause stunted plants. Those corn plants will never catch up to high yield potential.
The pressure to plant corn is high. The calendar says we are late. Farmers feel behind. When the weather warms, do not rush the shot and put yourselves either farther behind. Planting into good soil conditions provides the best chance for high yields this season. For more resources on corn planting and soil compaction, contact your county extension office.
Egli, D.B. and M. Rucker. 2012. Seed vigor and uniformity of emergence of corn seedlings. Crop Science. 52: 2774-2782.