Subsoiler

A subsoiler or flat lifter is a tractor-mounted farm implement used for deep tillage, loosening and breaking up soil at depths below the levels worked by moldboard ploughs, disc harrows, or rototillers.

Each shank is fitted with a replaceable point or foot, similar to a chisel plough, to break through the impervious layer, shattering the sub-soil to a depth of 45–75 cm (18–30 in).

Typically, a subsoiler mounted on a compact utility tractor will reach depths of about 30 cm (12 in) and have only one thin blade with a sharpened tip.

Points can be fitted with horizontal wings, about 30 cm (12 in) wide, which considerably increases the width of soil below ploughing depth loosened by the subsoiler.

Various manufacturers' brochures claim[citation needed] that crops perform well during hot and dry seasons because roots penetrate soil layers deeper to reach moisture and nutrients.

Brochures further claim that in wet conditions, the water passes more easily through the shattered areas, reducing the possibility of crops drowning.

A form of this implement (with a single blade), a pipe-and-cable-laying plough, is used to lay buried cables or pipes, without the need to dig a deep trench and re-fill it.