Water was spilling out of creeks, ditches and prairie potholes last week in corn and soybean fields across northern Iowa, which has been deluged by one of the wettest springs in decades.

“We’ve got water in places I haven’t seen since I was a kid,” says 38-year-old Pocahontas County farmer Brian Dreith, who said conditions are reminiscent of floods that occurred in 1991 and 1993.

Meanwhile, last week’s storms brought relief to farmers in far southern Iowa who had been scratching dry dirt and seeing corn leaves roll up in 90-plus degree temperatures. Severe drought conditions cover most of Davis County and parts of Appanoose, Van Buren and Lee counties, according to last week’s U.S. Drought Monitor.

“We received some much-needed rainfall in parts of south-central Iowa, which really helped the crops through the heat this past weekend,” Rebecca Vittetoe, Iowa State University Extension field agronomist in southeast and south-central Iowa, said on June 19....