Getting old fields back in shape

I have about 120 acres of old overgrown fields that I need to get back in shape. I ran a batwing over them the first week of August. They had not had anything done to them in a few years and were grown up with all types of weeds and some brushy type stuff. Some of it was over 5 feet tall. Underneath all the trash is some nice Bermuda of some type. I'm not good with grass ID yet. I looked at it last weekend and the weeds had started growing back. Should I run the batwing over it again (lower this time) and burn it? Do I need to spray it now and in spring? Just in spring? I have asked a few locals and get a different answer every time.

Getting old fields back in shape