How can I cut slots in the ground to install insulation panels?
Unless you're in the perfect type of sand/clay soil, with no gravel or rock larger than say 1/4&quot;, this won't happen. You'll have to excavate to the width of a backhoe. In the case of a mini-excavator, this might be 12&quot;.
If you have ideal soil you might get a cable trencher to clean out a slot, but they're really designed to backfill as they go.