Sounds like you have some soil building to do. Rye, clover, winter peas, etc, etc. I might go with a no-till rotation on things that really hold soil & benefit/build soil - which all of these do. I'd also be getting soil in to top shape with nutritional & PH needs. Manure fertilizer would be ideal as it offers so much more including organic matter. Lime as well.
Oh, just saw it doesn't have to be a food source..... Indian and big blue stem, great on clay. I'd probably be mixing with something else like a cool season grass if you really have some major erosion issues. If erosion issues are not that bad (only when you get 10" rains, wow), I'd just do BB & Indian. Indian being the best for poor soil in my opinion. Or trees may be an option if it wouldn't screw up some major dirt project you did (not sure exactly what situation you're talking about).
