[Gizmo2]

How deep ya goin?
What size pipe?

 

[Gizmo2]

I'm thinking backhoe or small excavator.

 

[Gizmo2]

A trencher might do pretty well at my place as long as it didn't hit any of the field nuggets we've got scattered around. Since OP's got known rocks, the bucket is the way to go since you'll never move them out of the path with a toothed chain like on a ditchwitch trencher.

Those trenchers are pretty sweet for productivity in the right soils.

If you have access to a backhoe, that'd be a good option too. The mini-ex's are made for this kind of stuff and you don't have to put down riggers or anything to get set up when you move. Sure, if it's got a pusher blade, then dropping that will make it more stable.

Handy for back filling too.