I also live in north Florida. After using the brush cutter an option beside using a disk would be, if you can tow a trailer across the bridge, rent a walk behind tiller, more work but it would turn up the ground. After seed spreading drag it with a section of chain link fence. Also the post regarding using Gly is right on. I have also found that most soils here in north Florida need dolomite added so whatever you plant will grow as desired. I would recommend going to your county agent and get a soil kit and have the University of Florida test it. Cost about $10. They will make good recommendations regarding ph and fertilizer. For fall planting winter wheat, oats and clover are a good choice. If turkeys are on your list chufa is a good choice also.