I dont know a hole lot about Iowa, except... It seems alot like Illinois... and being from Illinois originally.. it was always to green during the summer months to trip my trigger... I have made a few stands on Winter wheat feilds when they were freshly harvested... with some sucess... One thing I do know is.. That when feild corn is in that soft stage... almost like sweet corn... There are alot of coyotes laying around with full bellies.. and typicaly wont respond well... But its always worth a try...

Mike
Pure Predator Championship Calls
www.purepredator.com