A subsoiler or flat lifter is a

tractor A tractor is an engineering vehicle specifically designed to deliver a high tractive effort (or torque) at slow speeds, for the purposes of hauling a trailer or machinery such as that used in agriculture, mining or construction. Most common ...

-mounted

farm implement Agricultural equipment is any kind of machinery used on a farm to help with farming. The best-known example of this kind is the tractor. Tractor and power *Tractor / Two-wheel tractor * Tracked tractor / Caterpillar tractor Soil cultiv ...

used for deep

tillage Tillage is the agricultural preparation of soil by mechanical agitation of various types, such as digging, stirring, and overturning. Examples of human-powered tilling methods using hand tools include shoveling, picking, mattock work, hoein ...

, loosening and breaking up

soil Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former te ...

at depths below the levels worked by moldboard

plough A plough or plow ( US; both ) is a farm tool for loosening or turning the soil before sowing seed or planting. Ploughs were traditionally drawn by oxen and horses, but in modern farms are drawn by tractors. A plough may have a wooden, iron or ...

disc harrow A disc harrow is a harrow whose cutting edges are a row of concave metal discs, which may be scalloped or set at an oblique angle. It is an agricultural implement that is used to till the soil where crops are to be planted. It is also used to c ...

s, or

rototiller A cultivator is a piece of agricultural equipment used for secondary tillage. One sense of the name refers to frames with ''teeth'' (also called ''shanks'') that pierce the soil as they are dragged through it linearly. It also refers to mac ...

s. 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. The subsoiler is a tillage tool which will improve growth in all crops where

soil compaction In geotechnical engineering, soil compaction is the process in which stress applied to a soil causes densification as air is displaced from the pores between the soil grains. When stress is applied that causes densification due to water (or other ...

is a problem. In agriculture angled wings are used to lift and shatter the

hardpan In soil science, agriculture and gardening, hardpan or soil pan is a dense layer of soil, usually found below the uppermost topsoil layer. There are different types of hardpan, all sharing the general characteristic of being a distinct soil layer ...

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. The subsoiler consists of three or more heavy vertical shanks (standards) mounted on a toolbar or frame with shear bolts. They can be operated at depths of or more. A ripper normally runs deep. Shanks are curved and have replaceable tips. 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 . Subsoiling is a slow operation and requires high power input: 60 to 100 hp to pull a single subsoil point through a hard soil. Typically, a subsoiler mounted on a compact utility tractor will reach depths of about and have only one thin blade with a sharpened tip. The shanks should be inclined to the vertical at an angle greater than 25-30 degrees, preferably 45 degrees, and it is advisable that the height be adjustable. The points of the shanks are normally about wide and should be easy to replace. The condition of the points is very important: often the subsoiler fails to give good results due to the condition of its points. Points can be fitted with horizontal wings, about wide, which considerably increases the width of soil below ploughing depth loosened by the subsoiler. These plows are sometimes equipped with a torpedo-shaped attachment for making subsurface drainage channels. The subsoilers are raised and lowered hydraulically. Some models feature power-take-off (PTO)-driven vibrating devices. The typical spacing is between shanks. Shanks should be able to reach below the deepest compacted layer. Shank spacing and height should be adjustable in the field. Towed subsoilers should have gauge wheels to control the shank's depth. Shanks usually are from thick. Thinner shanks are suited for agricultural use. Thicker shanks hold up better in rocky conditions, but require larger, more powerful equipment to pull them and disturb the surface more. Various manufacturers' brochures claim 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. Agricultural subsoiler implements will have multiple deeper-reaching blades; each blade is called a scarifier or shank.

Purdue University Purdue University is a public land-grant research university in West Lafayette, Indiana, and the flagship campus of the Purdue University system. The university was founded in 1869 after Lafayette businessman John Purdue donated land and money ...

's Department of Agriculture indicates that common subsoilers for agricultural use are available with three, five or seven shanks. Subsoilers can be up to wide; some models are towed behind tractors while others are mounted to the

three-point hitch The three-point hitch (British English: three-point linkage) is a widely used type of hitch for attaching ploughs and other implements to an agricultural or industrial tractor. The three points resemble either a triangle, or the letter A. Three-p ...

.Purdue Ag Equipment Sizes & Storage
One type of subsoiler has a torpedo-shaped tip and is called a mole plough because the tip describes a path much like the

burrow An Eastern chipmunk at the entrance of its burrow A burrow is a hole or tunnel excavated into the ground by an animal to construct a space suitable for habitation or temporary refuge, or as a byproduct of locomotion. Burrows provide a form of sh ...

that a

mole Mole (or Molé) may refer to: Animals * Mole (animal) or "true mole", mammals in the family Talpidae, found in Eurasia and North America * Golden moles, southern African mammals in the family Chrysochloridae, similar to but unrelated to Talpida ...

creates. Mole ploughs are used to create

tile drainage Tile drainage is a form of agricultural drainage system that removes excess sub-surface water from fields to allow sufficient air space within the soil, proper cultivation, and access by heavy machinery to tend and harvest crops. While surface wate ...

, with or without tiles or tile line added. A form of this implement (with a single blade), a

pipe-and-cable-laying plough A pipe-and-cable-laying plough or moleplough is a method to bury cables or pipes. The machinery is a form of a subsoiler with a single blade. It is used to lay buried services of virtually any description, for drainage, water, electricity, telecom ...

, is used to lay buried cables or pipes, without the need to dig a deep trench and re-fill it.

References

{{reflist Agricultural machinery

See also

References