You can burn anything you want, if you own it. At a minimum you will want to call the rural fire dept to let them know your plans. If you talked nicely to them, perhaps you can plan a training exercise. They kind of did that with the airport earlier this summer.
As far as it staying smooth. Not a chance. Too many pocket gophers, badgers, rabbits, fox and other hole digging bastidges out that way. My land is rough as hell from them. I've thought about trying to smooth it out a bit as the it's pretty rough on the kidneys when out back on the tractor/UTV/pickup. I have a 6 ft tiller for my tractor but the experience I had with wormwood overtaking a small food plot I put in a couple years ago really keeps me from being overly excited about tilling anything. Actually, the couple acres I have broken up is going to get seeded back to grass this fall as I have most of the noxious weeds taken care of, finally.
Ive tossed around the idea of killing it, discing it a couple times and replanting right away with a pasture mix or maybe just alfalfa. Not sure how late in the fall can do that to avoid significant erosion come spring. I dont know what it is currently, but it aint pretty!