Cool soils stalling MO corn planters
Missouri farmers itching to plant corn find that soil temperatures are well below the 13-year average, according to University of Missouri Extension specialists.
Soil temperature, not air temperature, controls seed germination, said Brent Myers, new MU Extension cereal crops specialist. Soil temperature nearing 50 degrees Fahrenheit at 2 inches is a good target to begin planting for corn. It takes about seven days for corn to germinate and emerge. Early emergence could result in exposure to late frost. Late emergence leaves the seed in the soil longer and increases risk of disease.
At the end of March, soil temperatures in mid-Missouri inched up toward the 13-year average, according to Horizon Point, a custom weather-analysis service from the MU Commercial Agriculture Program. Air temperatures reached 67 degrees on the last day of the month, pushing soil temperatures above the 50-degree mark for the first time in 2013. Temperatures were average to 5 degrees below average, with nightly temperatures ranging from 30 to 42 degrees.
An April 8 USDA crop report showed that Missouri farmers had tilled only 25 percent of the ground, compared to 61 percent this time last year. The five-year average is 24 percent. The most recent report has 4 percent of the corn planting completed, four days behind normal.
There is still plenty of time for planting, said MU Extension agronomy specialist Bill Wiebold. Thanks to technology, all of Missouri’s corn crop can be planted in one week when conditions are right, he said.
The average date of the last spring frost in mid-Missouri is April 10, but northern Missouri remains vulnerable through April 20.
According to USDA estimates, the corn yield in 2012 was 123.4 bushels per acre, down from 147.2 bushels per acre in 2011, a 13 percent drop.
Missouri farmers plant 3 1/2 million acres of corn annually, Myers said. Those numbers likely will be down this year even though record snowfalls, as well as heavy rains in March and early April, increased soil moisture at depths below 3-4 feet.
The March 28 report from USDA’s National Agricultural Statistics Service says U.S. corn growers intend to plant 97.3 million acres of corn in 2013, slightly more corn than last year and 6 percent more than 2011. According to the report, this would represent the highest planted acreage in the U.S. since 1936, when an estimated 102 million acres were planted.
Myers noted that 2012 was the first year that drought-resistant seeds were sold. Yields showed the seeds had value in some situations, but more testing is needed.
In addition to temperatures slowing planting, some farmers are taking a wait-and-see attitude on anhydrous application due to seasonably late snowfall and moisture.
Editor's Note: Story by Linda Geist, University of Missouri Extension.