Wooddust,
I also grew up in Northern Ill. same soil there. Now am in Northern Miss. with sandy, clay soil and plenty of rocks. The heat, humidity seems to destroy any humus you try to work in the soil. (I keep telling the wife that I' m going to load the pickup with soil when we go back north to visit.) She laughs and tells me it will burn up in weeks. (I was a city boy and she was farm raised.)
Russ