A year ago, Doug Sorensen was prowling the Iowa Power Farming Show in Des Moines looking for a manufacturer to help market an attachment he invented to help keep planter gauge wheels clean.

This year, the Audubon County farmer was among the new exhibitors manning one of 75 new booths added to an event that is hailed as the third-largest indoor farm show in the United States. The show added an entire new floor of exhibits on the lower level of Hy-Vee Hall to accommodate the new vendors, bringing the total number of exhibitors to 750 companies spread across 7.7 acres in three buildings that comprise the Iowa Events...