Sub-Soiler how deep and how far apart?

[RPW]

Yep found the same info while doing a search online about subsoilers a few years ago. 4' passes depending on soil. Can't remember the brand I've got but it also has a shear bolt and I've tested it too I've use mine to help break roots on the Juniper trees (cedars) that we have. I've also found that when you hit something solid one of two things will happen....It will bring to to a dead stop immediately or you'll shear the bolt.