Bush hog down to a height of 12'-18'.

Lightly disc roadsides and cut rows with discs straight inline as to avoid deep harrowing. Stay off of hilly areas to avoid erosion.

Then, go to the local Co-Op and get a buggy of 17-17-17 w/crop mix and go over these same areas spreading it at a rate of approx. 150-200 lbs/acre.

Or, do as suggested and BURN!