Cool soils delay early corn planting
Missouri farmers itching to plant corn find that soil temperatures are well below the 13-year average of temperatures ideal for corn planting, 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 seed and seedling 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. Before this temperatures were average to 5 degrees below average, with nightly temperatures ranging from 30 to 42 degrees.
An April 8 USDA crop report showed 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. The Callaway County Missouri River bottoms average last spring frost date is April 15th versus the April 10th date for the rest of Callaway County and Central MO.
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. Even with the early planting last year the drought took its toll on our corn production.
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. Although, many central Missouri fields have shallow clay pans reducing the amount of moisture crops can use.
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 2012 was the first year when 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.
About Horizon Point
Horizon Point is a custom weather-analysis system. Information comes either from the National Weather Service or the MU Commercial Agriculture automated weather station network. Site-specific reports and advisories are designed to make weather information useful. Horizon Point reports include precipitation, temperature and wind forecasts as well as historical data.
You can sign up to receive free Horizon Point reports by email at agebb.missouri.edu/horizonpoint. Subscribers can choose what advisories they want and how often.
See a map of Missouri with the dates of last spring frosts averaged from 1971 to 2000 at: http://agebb.missouri.edu/news/pics/lg058a.jpg.
Source: Brent Myers, 573-882-4257; Raymond Massey, 573-884-7788; William Wiebold, 573-673-4128 (cell); 573-882-0621; Jim Jarman, 573-642-0755