Look again at that corn acreage.. there is not much change across the years.. IL flexed out of beans into Corn.. and then flexed back.. IL, IA, IN and OH peaked on that chart for Corn acreage in 2007.  For Soybeans those states peaked.. IL AND IN in 2006 IA and OH in 2010.

Most of the Cornbelt states ALREADY were farming all the acres they could.. short of some pasture ground and minor crop changes.

The BIG EXPANSION has come out of the plains.. and the switch out of Cotton.. this is Wheat, and lower yielding ground.. When you look at both the Corn and Soybean acreage.. this is undeniable.

To say that this DOES NOT impact National average yields is.. not being honest.. imho.