With that many rocks, I'm surprised it can grow/yield anything ?

I'm thinking, it'd be more productive to simply have a couple gravel/rock screening plants set up and go in with loaders and load the whole field in the screeners (maybe even set up the crushers on the screeners and make good class 1 or class 5 gravel, spread the dirt back over the scalped area.  Then you wouldn't have to pick rocks for a few years after that ?

Does the ground freeze to any depth in your area? Here, frost is what seems to bring the rocks up to the surface, from deep under the top soil. . . . . .

It always amazes me when you show your rock picking pic's . . . . I'll carry it in my pocket when I'm out picking and when I get to that little ridge in my field, I'll pull out the pic and compare it to what "little" I have to pick and appreciate I don't farm by you.