A couple yrs ago when I built my pond, actually maybe could be considered a lake I had a couple acres of really crappy clay on the back side of the dam that I was scared of erosion, so early in the spring, before growing season here in MO, I spread the whole back dam with a ton of rye and wheat and inter-seeded with clover and crown vetch. I spread a lime truck across the top of the dam but that didn't spread down the hill very far, I did put some triple 13 fertilizer on it, with a little rain that we got that thing greened up fast and about the time the rye and wheat matured and dried out the clover kicked in and I was able to get a very good mat to hold the soil, almost zero erosion. that was a huge relief because I didn't see anything growing on that nasty rocky clay soil for a long time, it is still going strong, the clover seems to reseed itself every yr, what little seeds that mature, the deer go across it and clip the heads of the clover almost as fast as it heads out every yr, the whole thing has actually become a big greenfield deer attractant for the last three yrs.
The bottom line is, like others have said, there is very little growing nutrients to be had in that red clay, any growth you get out of your seed is whatever fertilizers and other stimulants that you add to the soil, and it will probably be hard to get your water to stabilize till you get erosion down and clay from washing into the pond every time it rains. Good Luck!
