subsoiler

thumb|Subsoiler with a tooth packer roller A subsoiler or flat lifter is a piece of agricultural equipment used for deep tillage, loosening and breaking up soil at depths below the levels worked by moldboard ploughs, disc harrows, or rototillers. Most such tools will break up and turn over surface soil to a depth of , whereas a subsoiler will break up and loosen soil to twice those depths.

A subsoiler should not be confused with a mole plough: an agricultural implement used to create underground drainage channels, a technique known as mole drainage. The subsoiler is a tillage tool which will improve growth in all crops where soil compaction is a problem. In agriculture angled wings are used to lift and shatter the hardpan that builds up due to compaction. The design provides deep tillage, loosening soil deeper than a tiller or plough is capable of reaching. Agricultural subsoilers, according to the Unverferth Company, can disrupt hardpan ground down to depths. When a field is optimally subsoiled, crops will perform well during hot and dry seasons because roots penetrate soil layers deeper to reach moisture and nutrients. In wet conditions, the water passes more easily through the shattered areas, reducing the possibility of crops drowning.