USDA Prospective Plantings report shows corn acres slipping as soybeans gain.

Iowa is poised to lead the nation in corn production this year with 13.1 million intended acres, although analysts say even the heart of the Corn Belt isn’t immune to global pressures.

While fertilizer prices are rising, economists believe supplies purchased in advance will keep Iowa’s acreage more stable than other states. However, the U.S. Department of Agriculture’s (USDA) March...