science

Subsoiler

Subsoiler is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Subsoiler rather than just read about it. In short: 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 15–20 cm (6–8 in), whereas a subsoiler will break up and loosen soil to twice those depths.

Key takeaways

Subsoiler belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Subsoiler to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Subsoiler from memory before moving on to harder problems.

Reference excerpt

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 15–20 cm (6–8 in), 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 60 cm (24 in) 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. Agricultural implements that are not powered by human labor typically come in three types: self-propelled, trailed, or mounted. A self-propelled implement has its own drive system. Trailed and mounted implements, on the other hand, require an external power unit, such as a tractor. A trailed implement has its own chassis, while a mounted implement does not and is therefore lifted and lowered by the tractor's hydraulic system. Subsoilers are most commonly found in a mounted configuration. In countries where fields are generally larger, trailed subsoilers are also common. In both cases, a tractor is used as the power source.

Construction, Operation, and Characteristics 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 45–75 cm (18–30 in) or more. A ripper normally runs 35–45 cm (14–18 in) 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 45–75 cm (18–30 in). Subsoiling is a slow operation and requires high power input: 60 to 100 horsepower (45 to 75 kW) to pull a single subsoil point through a hard soil. 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. 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 30 cm (12 in) 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 30 cm (12 in) wide, which considerably increases the width of soil below ploughing depth loosened by the subsoiler. The subsoilers are raised and lowered hydraulically. Some models feature power-take-off (PTO)-driven vibrating devices. The typical spacing is 76–100 cm (30–39 in) between shanks. Shanks should be able to reach 2.5–5 cm (1–2 in) 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 2–4 cm (0.8–1.6 in) 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. Agricultural subsoiler implements will have multiple deeper-reaching blades; each blade is called a scarifier or shank. Purdue University's Department of Agriculture indicates that common subsoilers for agricultural use are available with three, five or seven shanks. Subsoilers can be up to 15 feet (4.6 m) wide.

See also Plough – Chisel plough Bulldozer ripper List of agricultural machinery

References

Illustrations

Worked examples

Example 1 — a first encounter with Subsoiler

Start with the simplest possible case. Write down what Subsoiler claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Subsoiler before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Subsoiler ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Subsoiler

In research: Subsoiler appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Subsoiler in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Subsoiler is common in secondary-school and first-year university syllabi. It links to neighbouring topics Agricultural machinery, so understanding it makes those chapters shorter.
In everyday life: Look for Subsoiler outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Subsoiler in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Subsoiler means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Subsoiler out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Subsoiler in simple terms?

Why does Subsoiler matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Subsoiler?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Subsoiler.