1) Agricultural machinery 
A subsoiler or mole plough 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 15-30 cm (6-8 in) while a subsoiler will break up and loosen soil to twice those depths. Typic...
one who operates a subsoil plow. · See