Forty-five to 75 bushels/acre in northwest Illinois. One hundred to 170 in north-central Iowa. Twenty to 50 in southeast Missouri.

Those are just a few examples of the corn yields coming in from the early stages of the 2012 corn harvest. Many farmers report extreme variability under the constant of drought-shortened yields as harvest progress nears the 25% completion mark.

"Our yields are all over the place. The worst are our continuous corn fields, of which most of those are making 50 to 75 bushels/acre," says Mount Pulaski, Illinois, farmer Doug Martin. "We have had a few first-year corn fields make it into the 140 range and 1 that made 175, but overall I think we will average around 100 [bu/ac]."

Martin's farm isn't the only one where that kind of range in yields is common. In fact, the entire state of Illinois will likely see a 50-bushel range in yields when it's all said and done this fall, says Agriculture.com Marketing Talk frequent contributor 67guy.

"I'm having very hard time getting a good handle on what yields will be in this area...just way too much variability within one field to put a yield figure on it and be confident," says 67guy, who farms in north-central Illinois. "It looks worse than 2005, but I blew the call in 2005, so don't read too much into that. The state yield will be much worse than '05 because that was kind of a regional drought that left some parts of the state unscathed. I'm pretty sure we are over 100 bushels/acre here but probably under 150. Quite a range, huh?"

• See all the latest yield reports