We have about 6 food plots, total of about 8 acres, up in the mountains in Vermont. Very rocky in spots.
Removing the rocks is not easy, but if you want good, tillable, workable soil, it is a must.
We did it as follows. First a three bottom, re-settable plow (Kverneland AB 85). Don't worry too much about damaging a "bottom plow" as long as it is re-settable. They are designed to work through big rocks. Then after plowing, come through with a stone fork or
grapple to pick out the big rocks. Stone fork is preferable. Most have solid, round tines and are spaced more closely than a root
grapple. Many root grapples have welded on tips. These will eventually work loose & fall off when handling a lot of rocks. Next, disc harrow. To really get the land pretty rock free, it will take several seasons. I generally run the tractor with a stone fork on front & plow on back when working the fields to plow & remove rocks. That way when I hit a big one, I can pull it out with the stone fork before it potentially gets covered in the next plow pass.
A harrow will not remove the rocks. In most cases, it will run over them & eventually tear the discs off of the bearing. You need the plow, a resettable, to turn up the rocks. Then remove the rocks either with a stone fork, a root
grapple or by hand and toss into an FEL bucket.
It will take 2-3 seasons before you stop turning up major rocks. But if you really want a rock free garden, this is one way to do it.
We learned these lessons the hard way.... doing it another way first & screwing up or tearing up equipment.