Soil temperatures across much of Iowa last week ranged from 30 to 35 degrees F, with some locations still reporting frost in the soil. So far in April, temperatures have been colder than average with better-than-average precipitation. “There’s no need for farmers to push the issue with early corn planting,” says Dennis Todey, director of USDA’s Midwest Climate Hub in Ames.
Soil moisture has increased across Iowa. The early spring precipitation has been welcome in south-central and southeast Iowa. That area had the most severe drought conditions of anywhere in the state in 2017, but conditions are now improving. “We have moisture in the soil,” says ISU Extension field agronomist Rebecca Vittetoe, who covers south-central Iowa. “We’re not back to 100% everywhere, but the supply of subsoil moisture has improved.”
Late spring hinders cover crop growth
In north-central Iowa, ISU field agronomist Angie Rieck-Hinz says the late developing spring is affecting cover crop termination. That’s happening all over Iowa, she says. Agronomists recommend farmers terminate cover crops 10 days to two weeks before planting corn.
USDA’s latest Iowa Crop Progress and Weather Report, for the week ending April 8, says, “Another week of cold, wet weather prevented nearly all fieldwork and continued to challenge cow-calf producers. Just 4% of the Iowa oat crop has been planted, more than a week behind last year and the five-year average. “The weather forecast for the next couple of weeks looks mixed, so we are still likely a few weeks out from widespread spring fieldwork,” says Mike Naig, Iowa secretary of agriculture.
Another cold, wet week prevented fieldwork across most of Iowa with just eight-tenths of a day suitable for fieldwork during the entire week ending April 8. Isolated reports of grain hauling from farms to elevators and processors, and fertilizer application in a few fields, were received.
Topsoil moisture levels rate 2% very short, 7% short, 76% adequate and 15% surplus. Subsoil moisture levels are 3% very short, 12% short, 77% adequate and 8% surplus. South-central and southeast Iowa moisture conditions continue to be dry with over one-third of topsoil short to very short and over one-half of subsoil short to very short.
As of April 8, only 4% of Iowa’s expected oat crop has been planted for 2018. That’s eight days behind both last year and the five-year average.
Livestock conditions continue to be mixed. Cold temperatures and snow have hampered early-spring pasture growth and continue to present challenges for calving throughout much of Iowa.
Weather summary for week ending April 8
According to Michael Timlin, regional climatologist, Midwestern Regional Climate Center, temperatures were well below normal across Iowa last week, averaging 16 to 19 degrees below normal. Daily minimum temperatures remained below freezing all week. Warmest day was April 5 when temperatures rose into the 60s in southwest and south-central Iowa. Lamoni, Clarinda and Shenandoah all reached 62 degrees that day.
Cold weather keeps soil temps down
The coldest reading, minus 3 degrees, was at Waukon on April 7. Cold weather kept soil temperatures down, with readings remaining in the low to mid-30s as of April 8. Precipitation was also well below normal for much of Iowa. The southern two-thirds of the state had deficits greater than 0.40 inch for the seven-day period. Only northwest Iowa had near-normal precipitation for the week.
Rainfall totals were less than 50% of normal for much of the state, and less than 10% of normal in parts of west-central and central Iowa. The highest precipitation total was 0.74 inch in Pocahontas and the lowest total was zero inches at a handful of stations. Snow fell across the southern edge of Iowa on April 2 and fell across the northern third of the state later in the week. Highest snow totals were just over 10 inches at a couple of Mason City area stations.