I live in Georgia where clay is a big problem. On all my dam areas and other high erosion areas I plant Lezpadeza. Lezpadeza will litterly almost grow in concrete and will proliferate and in some cases take over an area.
It is illegal in some states to plant Lezpadeza so you need to check with your local laws. In Georgia I use Kobe Lezpedza. Athen Seed company in Georgia will ship to most states I believe.
My typical procedure on new reclaimed forest areas of pine and clay is as follows:
1.) Let weeds come up first year and drop at least 2 tons lime on ground
2.) Plow/Rototill 2nd year
3.) Fertilize/Plant
I know this does not answer the original question but for those of you having problems with Clay look at Lezpadeza.
