scmn_06 - I assume you've allowed for the additional N from the beans....many of our customers report that as KSUfan says the difference narrows on 3rd year and later. Soil microbes get up and running expecting corn. Lots of possible reasons, I'm just taking a guess. Profitability, as I think I read in your posts, however looks very good for COC even in the 2nd year. I bet as KSU does that 3rd year COC and later transitions in yield AND profitability. jmho. Jim at Dawn | 
Corn on Corn vs. Corn on Bean Yields
