Between 1996 and 2017, the sum of acres planted to corn, soybeans, and wheat have varied within a tight band for the state of Illinois. It has ranged from 22.0 million to 22.7 million acres for the three crops. Over this period acreage planted to wheat has been small and declining. It has decreased from 1.7 million in 1996 to just half-a-million in 2017. University of Illinois Agricultural Economist Gary Schnitkey says most of the acreage switches in the state have been between corn and soybeans.
These are the historical facts for Illinois. In 1998, corn and soybean acres were each at 10.6 million. With some yearly variations, corn acres then increased and soybean acres generally decreased from 1998 to 2012. In 2012, 12.8 million acres of corn were planted and 9.0 million acres of soybeans. Since then, corn acres have decreased and soybean acres have increased. Corn acres declined from 12.8 million in 2012 to 11.2 million in 2016. Soybean increased from 9.0 million to that same 11.2 million over the same period.