Crop planting is underway amid lingering concerns about soil moisture

By Jared Strong, Iowa Capital Dispatch

Warm soil temperatures and favorable weather have allowed farmers across Iowa to start planting corn and soybeans this week, according to several field agronomists.

Wednesday was the earliest planting date for corn to be eligible for federal crop insurance replanting payments, which cover farmers if their young crops are damaged and need to be replaced. The earliest planting date for soybeans was also Wednesday for the southern three tiers of Iowa counties, and it’s April 15 for the rest of the state.

“Kickoff has occurred, and we’re just getting going on the first quarter here,” said Aaron Saeugling, an Iowa State Extension field agronomist who monitors southwest Iowa.

Most of the state’s topsoil has a temperature of at least 50 degrees, according to Iowa State University data. That temperature is a key threshold for seed germination. Soil temps are predicted to rise into the 60s in the coming days before retreating into the 40s by the end of next week.

Air temperatures are expected to peak in the 80s in most of Iowa this weekend, according to the National Weather Service.

“Given the incredibly warm forecast, across entire fields it should be excellent conditions for that crop to be germinating and getting off to an even start,” said Meghan Anderson, an Extension field agronomist in central Iowa.

Heavy rainfall in wide areas of the state in March helped alleviate drought conditions that have persisted for more than three years. Still, available soil moisture is far behind what it has been in recent years, and a small part of the state including Floyd County is still classified as being in extreme drought.

About 51% of the state’s topsoil and 36% of its subsoil have adequate or surplus moisture, according to a U.S. Department of Agriculture report on Monday. At this time last year, those figures were 78% and 66%.

The depleted subsoil is most worrisome for the field agronomists.

“We’ve got adequate topsoil,” Saeugling said. “The rainfall that we got in March and the snow that melted was enough to give us some close-to-normal topsoil. But you just drive around and look at some of these tile lines and look at some of these low river levels and it’s concerning, long term.”

About two-thirds of the state is suffering from some measure of drought, according to a Thursday report by the U.S. Drought Monitor. That affected area has declined for weeks and was aided again last week by heavy rainfall in southeast Iowa, which delayed planting in that area.

“Things are just a bit on the dampish side yet,” said Virgil Schmitt, an Extension field agronomist who monitors far southeast Iowa. “We’re kind of the wet spot of Iowa. Over the last week I’ve seen more water runoff, more ponding, than I’ve seen in over a year. The soils are holding everything they can hold.”

Those rains have alleviated some of the concerns about available water for livestock along the state’s southern border, field agronomist Clarabell Probasco said.

“Ponds were in a rough state when we came into spring,” she said. “A lot of livestock producers were worried about relying on ponds for watering their livestock: ‘Is it even gonna make it through summer?’ But there have been a lot of farms that have made drastic improvements.”

— Iowa Capital Dispatch is part of States Newsroom, a nonprofit news network supported by grants and a coalition of donors as a 501c(3) public charity. Iowa Capital Dispatch maintains editorial independence. Contact Editor Kathie Obradovich for questions: info@iowacapitaldispatch.com. Follow Iowa Capital Dispatch on Facebook and Twitter.