Completely agree with THE LLC. Rather than spend the money, time and effort with stuff like pearl millet, sunn hemp etc., just put down lime. Long term, you'll be much happier with the results. There will be native vegetation that will establish - blackberry, broomstraw, if there are pine trees around the seed will sprout in it. Just mow it once a year or two and you'll have productive ground quicker than you'll ever get by messing with cereal rye, millet, etc.