Paul-- Yes, Monsanto's seeds must be bought every year unlike the past. I don't think they rotate all that much. I see corn in Minnesota year after year after year in some of the same fields. The problem is that super weeds have developed, thus Dicamba has been developed. Super weeds hurt yields. Last year there was a major problems with Dicamba and "drift". Dicamba was developed because of the super weeds. One farmer with GM plants modified to accept Dicamba use in and neighboring farmers non GM crops are heavily damaged from "Drift", spraying with wind. So other farmers yields are affected negatively. Many articles on the topic's, I link a few at the bottom, but the pro's and con's probably exaggerate.. My 3 years is just a number of mine, it might be longer, but yields are debatable regardless of the year.
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