Iowa farmers are bucking the national trend with plans to plant more corn acres than they did a year ago, the only one of the top six corn-growing states where corn plantings will rise, according to the U.S. Department of Agriculture’s (USDA) prospective plantings report released last week.

Nationally, corn plantings are expected to be the lowest since 2010 as farmers switch some corn-on-corn acres to soybeans due to economics and pest issues.

"When I talk to farmers, I get the sense that they want to shift to a more balanced rotation," said AgriVisor analyst senior market Dale Durchholz. Late-arriving spring weather could also hold down corn acres, he said.

"When you step...