In the central sands of wisconsin many potato farmers are also turning to alfalfa as a cover crop. University research shows 10-15% increase in production on corn after a rotation of alfalfa.
If one has higher pH ground and soil that is sandy. One might want to consider alfalfa over the clovers. Side note, if one is taking crp land out and putting into crop land, roundup ready alfalfa is one YEAR ONE option. I have had a few accounts do this exact thing this year.
Here is a tip. If you are going to fall seed alfalfa, you want to choose a variety that doesn't go dormant as early. The winter hardy type alfalfas are the opposite of what you want to plant for alfalfa if your going to plant late august or early september.
Here is another tip...use INTX innoculated alfalfa or buy a pack of their PREVAIL innoculant to add to whatever alfalfa you bought. The innoculant isn't just organic, it's not just omri certified, it also contains my secret weapon for fast growing EVERYTHING....Azospirillum. "Azo" is a natural bacteria/growth promoter.
Yes, I try to use growth promoters on everything. I foliar feed everything and i aerate the soil everywhere. You will be amazed at what you see.