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.
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 depth is deeper than a tiller or plough is capable of reaching. Agricultural subsoilers can disrupt hardpan ground down to 60 cm (24 in) depths.The subsoiler consists of three or more heavy vertical shanks (standards) mounted on a toolbar or frame with share bolts.