Agronomists say you shouldn't plant corn until the soil temperature is 50 degrees F at the 4 inch depth. How important is that number when you look at the calendar and see it's the 15th of April?
"That's kind of a magic number, 50 degrees, for planting corn," observes Jim Fawcett, an Iowa State University Extension field agronomist in eastern Iowa. "That's when corn will germinate, with a soil temperature of 50 degrees or higher. The reason for not planting before that is the seed actually will take up water with soil temperatures cooler than 50 degrees. The seed will swell, but it doesn't germinate. That's not a good combination because the seed will tend to rot if it's just sitting there swelling in the soil but not germinating. The seed imbibes the water, takes it in, but doesn't germinate because it's too cold."
Fawcett adds, "Particularly in April, I would definitely be paying attention to soil temperature before I decide to plant corn."
Especially in April, pay attention to soil temperature before deciding to plant
The week of April 7 Iowa received some much needed rain. In some localized areas of the state the rain came too much, too fast. Are there any concerns that the soil isn't going to be ready to go, when the temperature and the calendar finally say it's time to plant corn? Fawcett and other ISU Extension field agronomists don't think we'll be seeing many planters going this week in Iowa, the week beginning April 14. "We are pretty wet now here in eastern Iowa, and actually do have some excess moisture in places," he noted on April 10. "But I don't hear farmers complaining—not after going through the historic drought of last year."
Every decision that you make influences the size and scope for corn yields. From the corn hybrid you select to the seeding rate and row width you choose. Download our FREE report over Maximizing Your Corn Yield.