Jim Lux wrote in
:

On the other hand, there's a big difference between a "slit into which
a cable/small conduit can be stuffed" and a 4" wide trench with a
ridge of dirt along side.


Models are available here which cut a trench about 2" wide, and to a depth
of about 18" max, and pile the fine spoil neatly clear of the trench
(rather than in the operator's boot etc).

I have used them on electrical contracting jobs, and they work a treat.
They will cut through small tree roots, deal with small rocks, and are easy
to backfill neatly.

Owen