We had a similar problem with part of our land. We consulted an agricultural seed company and they sent someone out to assess our field. The visit didn't cost us a groat. At the appropriate time we received a sack of a great seed mixture, specific to our land and our needs. That field area is about 2 1/2 acres. We broke up the surface with a rake, which left small slits with soil visible. Then we sprinkled the seed evenly over the whole area, by hand, just before it rained and washed the seeds down into the slits. The improvement took a while to see but it was well worth it, and the cost was not high. We felt that it was worth finding out from someone who knew what he was talking about, and there was no purchase pressure.