Anything will do from bargain priced grass at the local garden center to pricey clovers aimed at deer hunters.If need be borrow or rent a brush hog and chain saw to open things up.That alone will get things growing even without planting and you can use the cuttings for brush piles.How big is your field?If there's a farmer nearby with livestock maybe you could cut a deal with him to plant alfalfa or something.Good luck!