A subsoiler is a tractor mounted implement used to loosen and break up soil at depths below the level of a traditional disk harrow or rototiller. Most tractor mounted cultivation tools will break up and turn over surface soil to a depth of 6" to 8" while a subsoiler will break up and loosen soil to twice those depths. Typically subsoiler mounted to a Compact Utility Tractor will reach depths of about 12" and typically have only one thin blade with a sharpened tip