Your on the right page. Do the Round-Up thing to the area first then bush hog and wait for a few weeks. Then if anything turns green re spray with the Round-Up. You should be able to burn if the dead stuff is less than 6 inches. Then disk throughly and then lime and float disk the lime in. If you are going to wait until fall you will want to disk and Round-Up a few more times. You should have a great field. Do the soil sample now.