Subsoiler

A subsoiler is a piece of tillage equipment that loosens and breaks up compacted soil at depths below what a moldboard plough, disc harrow or rototiller can reach, commonly twice the 15 to 20 centimeter depth of ordinary tillage and, on some machines, as deep as 60 centimeters through hardpan. It is built from three or more heavy vertical shanks mounted on a toolbar, each fitted with a replaceable point that shatters compacted layers as a tractor pulls or hydraulically drives the frame through the field. Subsoiling lets crop roots reach deeper for moisture and nutrients in hot, dry seasons and improves drainage in wet ones, though it is a slow operation that demands high tractor power, typically 60 to 100 horsepower for a single point.