Rainfall slows farmers as optimal planting window shrinks

Farmers should plant their corn by next week to ensure their yields are maximized, but wet fields have stalled their progress, according to the U.S. Department of Agriculture.

Corn planting had been tracking ahead of the five-year average in April before last week’s rains that touched every part of the state. There was a statewide average of 2.23 inches of precipitation, which was more than double what is typically expected.

By Sunday, corn planting had sagged to put farmers slower than the five-year average — about two days behind that schedule, the USDA reported.

“All this rain has basically stopped planting for most people,” said Meaghan Anderson, an Iowa State University Extension field agronomist who monitors central Iowa. “It might be the weekend before people can get back in the field.”

ISU research has shown that corn yields are typically highest in Iowa if farmers plant during a roughly four-week stretch from mid-April to mid-May. Yields start to diminish rapidly thereafter.

Planting in soil that is too wet can also stunt growth and yields.

After Wednesday there are no indications of massive storms for the next week, said Cory Martin, a meteorologist for the National Weather Service.

Temperatures are expected to be about average for the rest of this week and to warm into next week.

“A lot of these guys are pretty experienced, and deep down they want to get in as soon as they can,” Gentry Sorenson, an Extension field agronomist in far northern Iowa, said of farmers in his area. “It doesn’t take long to accomplish what they need to do with the planting equipment they have.”

Soybean planting was also delayed by about a week by the rains, the USDA reported, and on Sunday it was about two days behind last year’s progress.

The abundant rainfall in recent weeks has helped alleviate persistent drought conditions. About 84% of the topsoil in crop fields has adequate or surplus moisture. About 73% of subsoil rates the same.