Subsoiler (Agriculture Glossary)

Subsoiler :Also flat lifter.

A tractor-mounted farm implement used for tilling soil at depths much below the levels normally worked by mouldboard ploughs, disc harrows, or rototillers. While most such tools break up and turn over surface soil to a depth of 15–20 centimetres (5.9–7.9 in), subsoilers can often extend the action to as deep as 75 centimetres (30 in). They typically consist of three or more heavy, curved shanks with replaceable points and sometimes fitted with horizontal wings, which are used to lift and shatter the hardpan that builds up in deeper layers due to soil compaction.