Has anybody used one? Do they work like advertised? They are supposed to be used around the edges of crop fields to keep the trees from taking water from the crops.

Call before you dig

Are you talking about a subsoiler?

That is what I would like to know.

I goggled it, looks like a large undercutter/bed lifter pulled by a D7. I imagine it shears roots on the horizontal.

Check state laws if they are not your trees, trees have insane replacement value and what you can do to trees that originate on neighbors property varies by state.

Farmers around here used to run ansubsoiler around the woods line on fields to cut the roots that were growing into thier fields. Now subsoiler rippers are on the planters and the little single point subsoilers are a thing of the past.

The local chapter of Quail Unlimited had a root plow for farmers to borrow to cut the roots on the hedge trees instead of pushing out the hedge row.

I have never used one but I believe it is a single point ripper meant to cut through roots at the edge of a field. We own the trees around the fields so that is not a problem. From what I know it doesn't kill the trees. Our fish and game department used to promote their use to keep farmers from pushing out brush.

I need one BAD!

our county soil district rents one out

If the roots are on my side of the line they are my roots.

I think I have one didn't really know what it was kinda resembles a 3 point hitch single bottom plow but no moldboard just a wedge about 3 in. thick tapering to the point I thought it was for draining wet spots

That may be so in your state but you should be absolutely sure of what your state law says before you endanger a tree not originating on your property. In same states you can be held liable and replacement value on a wind break of trees could be Hundreds of Thousands on the LOW END.