Our well is 600 ft from the house and I will be running 2 inch PVC the entire distance. The local plumbing place said that long of a run I should use O-Ring pvc and not glued pvc in case there is any ground movement. They cary both and the price is about the same. We live in southern Oklahoma where it only freezes once or twice in the winter. The water line will be about 2 ft. deep and through a hay meadow with heavy tractors running over it but only when it's hot and dry. What's your opinion?

600' - O-rings.

Check the frost line in your area. See what the requirement is for water burial depths.

Looks like 2' is fine for crush resitance. See Burial Depths – North American Pipe (http://www.northamericanpipe.com/tech/burialdepths.html)

The local plumbing place said that long of a run I should use O-Ring pvc and not glued pvc in case there is any ground movement.
You know more about the ground movement in your area but if it were my call I'd use glue joints underground. PVC will flex a bit in a long run so I think your plumbers concerns are needless, Good luck, Tom

Our well is 600 ft from the house and I will be running 2 inch PVC the entire distance. The local plumbing place said that long of a run I should use O-Ring pvc and not glued pvc in case their is any ground movement. They cary both and the price is about the same. We live in southern Oklahoma where it only freezes once or twice in the winter. The water line will be about 2 ft. deep and through a hay meadow with heavy tractors running over it but only when it's hot and dry. What's your opinion?

Having never seen gasketed PVC pipe smaller than 3", I'm guessing it must be a regional thing.

In my neck of the woods, we don't use gasketed piping or fittings for high pressure applications, we mainly use it for side sewers or waterline chases for piping passing under concrete driveways or sidewalks.