Harrow (tool)

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A spring-tooth drag harrow 12 foot spring-tooth drag harrow.jpg
A spring-tooth drag harrow
Disc harrows Diskharrow.png
Disc harrows
Crumbler roller, commonly used to compact soil after it has been loosened by a harrow Crumbler roller on a field near Karkur.jpg
Crumbler roller, commonly used to compact soil after it has been loosened by a harrow
Clydesdale horses pulling spike harrows, Murrurundi, New South Wales, Australia Clydesdales-harrows.JPG
Clydesdale horses pulling spike harrows, Murrurundi, New South Wales, Australia

In agriculture, a harrow is a farm implement used for surface tillage. It is used after ploughing for breaking up and smoothing out the surface of the soil. The purpose of harrowing is to break up clods and to provide a soil structure, called tilth, that is suitable for planting seeds. Coarser harrowing may also be used to remove weeds and to cover seed after sowing.

Contents

Harrows differ from ploughs, which cut the upper 12 to 25 centimetre (5 to 10 in) layer of soil, and leave furrows, parallel trenches. Harrows differ from cultivators in that they disturb the whole surface of the soil, while a cultivator instead disturbs only narrow tracks between the crop rows to kill weeds.

There are four general types of harrows: disc harrows, tine harrows (including spring-tooth harrows, drag harrows, and spike harrows), chain harrows, and chain-disk harrows. Harrows were originally drawn by draft animals, such as horses, mules, or oxen, or in some times and places by manual labourers. In modern practice they are almost always tractor-mounted implements, either trailed after the tractor by a drawbar or mounted on the three-point hitch.

A modern development of the traditional harrow is the rotary power harrow, often just called a power harrow. [1]

Harrow action

In modern mechanized farming, generally a farmer will use two harrows, one after the other. The disk harrow is used first to slice up the large clods left by the mould-board plough, followed by the spring-tooth harrow. To save time and fuel they may be pulled by one tractor; the disk hitched to the tractor, and the spring-tooth hitched to, and directly behind, the disk. The result is a smooth field with powdery dirt at the surface.

Types

In cooler climates the most common types are the disc harrow , the chain harrow, the tine harrow or spike harrow and the spring tine harrow . Chain harrows are often used for lighter work such as levelling the tilth or covering seed, while disc harrows are typically used for heavy work, such as following ploughing to break up the sod. In addition, there are various types of power harrow, in which the cultivators are power-driven from the tractor rather than depending on its forward motion.

Tine harrows are used to refine seed-bed condition before planting, to remove small weeds in growing crops and to loosen the inter-row soils to allow for water to soak into the subsoil. The fourth is a chain disk harrow. Disk attached to chains are pulled at an angle over the ground. These harrows move rapidly across the surface. The chain and disk rotate to stay clean while breaking up the top surface to about 1 inch (3 cm) deep. A smooth seedbed is prepared for planting with one pass.

Harrowing with tractor and disk harrow in the 1940s) Man harrowing with tractor and disk harrow (1295027).jpg
Harrowing with tractor and disk harrow in the 1940s)

Chain harrowing can be used on pasture land to spread out dung, and to break up dead material (thatch) in the sward, and similarly in sports-ground maintenance a light chain harrowing is often used to level off the ground after heavy use, to remove and smooth out boot marks and indentations. Used on tilled land in combination with the other two types, chain harrowing rolls remaining larger soil clumps to the surface where weather breaks them down and prevents interference with seed germination.

All four harrow types can be used in one pass to prepare soil for seeding. It is also common to use any combination of two harrows for a variety of tilling processes. Where harrowing provides a very fine tilth, or the soil is very light so that it might easily be wind-blown, a roller is often added as the last of the set.

Harrows may be of several types and weights, depending on their purpose. They almost always consist of a rigid frame that holds discs, teeth, linked chains, or other means of moving soil—but tine and chain harrows are often only supported by a rigid towing-bar at the front of the set.

In the southern hemisphere, so-called giant discs are a specialised kind of disc harrows that can stand in for a plough in rough country where a mouldboard plough cannot handle tree-stumps and rocks, and a disc-plough is too slow (because of its limited number of discs). Giant scalloped-edged discs operate in a set, or frame, that is often weighted with concrete or steel blocks to improve penetration of the cutting edges. This sort of cultivation is usually followed by broadcast fertilisation and seeding, rather than drilled or row seeding.

A drag is a heavy harrow.

19th century spike harrows Erpice 1849.jpg
19th century spike harrows

Power harrow

A rotary power harrow, or simply power harrow, has multiple sets of vertical tines. Each set of tines is rotated on a vertical axis and tills the soil horizontally. The result is that, unlike a rotary tiller, soil layers are not turned over or inverted, which is useful in preventing dormant weed seeds from being brought to the surface, and there is no horizontal slicing of the subsurface soil that can lead to hardpan formation. [2]

Historical reference

Spike harrow depicted on a 16th-century German coat-of-arms Ex-libris Schaftlarn 01.jpg
Spike harrow depicted on a 16th-century German coat-of-arms

In Europe, harrows were used in antiquity [3] and the Middle Ages. [4] The oldest known illustration of a harrow is in Scene 10 of the eleventh-century Bayeux Tapestry. An Arabic reference to harrows is to be found in Abu Bakr Ibn Wahshiyya's Nabatean Agriculture (Kitab al-Filaha al-Nabatiyya), of the 10th century, but claiming knowledge from Babylonian sources.

See also

Related Research Articles

<span class="mw-page-title-main">Plough</span> Tool or farm implement

A plough or plow 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 steel frame with a blade attached to cut and loosen the soil. It has been fundamental to farming for most of history. The earliest ploughs had no wheels; such a plough was known to the Romans as an aratrum. Celtic peoples first came to use wheeled ploughs in the Roman era.

<span class="mw-page-title-main">Tillage</span> Preparation of soil by mechanical agitation

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, hoeing, and raking. Examples of draft-animal-powered or mechanized work include ploughing, rototilling, rolling with cultipackers or other rollers, harrowing, and cultivating with cultivator shanks (teeth).

<span class="mw-page-title-main">Tractor</span> Engineering vehicle specifically designed to deliver a high tractive effort

A tractor is an engineering vehicle specifically designed to deliver a high tractive effort at slow speeds, for the purposes of hauling a trailer or machinery such as that used in agriculture, mining or construction. Most commonly, the term is used to describe a farm vehicle that provides the power and traction to mechanize agricultural tasks, especially tillage, and now many more. Agricultural implements may be towed behind or mounted on the tractor, and the tractor may also provide a source of power if the implement is mechanised.

<span class="mw-page-title-main">Seedbed</span> Local soil where seeds are planted

A seedbed or seedling bed is the local soil environment in which seeds are planted. Often it comprises not only the soil but also a specially prepared cold frame, hotbed or raised bed used to grow the seedlings in a controlled environment into larger young plants before transplanting them into a garden or field. A seedling bed is used to increase the number of seeds that germinate.

The stale seed bed or false seed bed method is a weed control technique used at both the farm and garden scales. In this that the young weeds can then be easily eliminated. By destroying them early, the farmer or gardener eliminates most of that season's annual weeds, which reduces their labor and improves their crop yields.

<span class="mw-page-title-main">Hoe (tool)</span> Agricultural tool

A hoe is an ancient and versatile agricultural and horticultural hand tool used to shape soil, remove weeds, clear soil, and harvest root crops. Shaping the soil includes piling soil around the base of plants (hilling), digging narrow furrows (drills) and shallow trenches for planting seeds or bulbs. Weeding with a hoe includes agitating the surface of the soil or cutting foliage from roots, and clearing the soil of old roots and crop residues. Hoes for digging and moving soil are used to harvest root crops such as potatoes.

<span class="mw-page-title-main">Roller (agricultural tool)</span> Tool for flattening land or breaking up soil

The roller is an agricultural tool used for flattening land or breaking up large clumps of soil, especially after ploughing or disc harrowing. Typically, rollers are pulled by tractors or, prior to mechanisation, a team of animals such as horses or oxen. As well as for agricultural purposes, rollers are used on cricket pitches and residential lawn areas.

<span class="mw-page-title-main">Rake (tool)</span> Agricultural tool used for moving soil

A rake is a broom for outside use; a horticultural implement consisting of a toothed bar fixed transversely to a handle, or tines fixed to a handle, and used to collect leaves, hay, grass, etc., and in gardening, for loosening the soil, light weeding and levelling, removing dead grass from lawns, and generally for purposes performed in agriculture by the harrow.

Tilth is a physical condition of soil, especially in relation to its suitability for planting or growing a crop. Factors that determine tilth include the formation and stability of aggregated soil particles, moisture content, degree of aeration, soil biota, rate of water infiltration and drainage. Tilth can change rapidly, depending on environmental factors such as changes in moisture, tillage and soil amendments. The objective of tillage is to improve tilth, thereby increasing crop production; in the long term, however, conventional tillage, especially plowing, often has the opposite effect, causing the soil carbon sponge to oxidize, break down and become compacted.

<span class="mw-page-title-main">Cultivator</span> Farm implement used for secondary tillage

A cultivator is a piece of agricultural equipment used for secondary tillage. One sense of the name refers to frames with teeth that pierce the soil as they are dragged through it linearly. It also refers to machines that use the rotary motion of disks or teeth to accomplish a similar result. The rotary tiller is a principal example.

<span class="mw-page-title-main">Ard (plough)</span> Simple light plough without a mouldboard

The ard, ard plough, or scratch plough is a simple light plough without a mouldboard. It is symmetrical on either side of its line of draft and is fitted with a symmetrical share that traces a shallow furrow but does not invert the soil. It began to be replaced in China by the heavy carruca turnplough in the 1st century, and in most of Europe from the 7th century.

<span class="mw-page-title-main">Subsoiler</span> Farm implement

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. 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.

<span class="mw-page-title-main">Two-wheel tractor</span>

Two-wheel tractor or walking tractor are generic terms understood in the US and in parts of Europe to represent a single-axle tractor, which is a tractor with one axle, self-powered and self-propelled, which can pull and power various farm implements such as a trailer, cultivator or harrow, a plough, or various seeders and harvesters. The operator usually walks behind it or rides the implement being towed. Similar terms are mistakenly applied to the household rotary tiller or power tiller; although these may be wheeled and/or self-propelled, they are not tailored for towing implements. A two-wheeled tractor specializes in pulling any of numerous types of implements, whereas rotary tillers specialize in soil tillage with their dedicated digging tools. This article concerns two-wheeled tractors as distinguished from such tillers.

<span class="mw-page-title-main">Flail mower</span> Powered vegetation cutter

A flail mower is a type of powered garden/agricultural equipment which is used to deal with heavier grass/scrub which a normal lawn mower could not cope with. Some smaller models are self-powered, but many are PTO driven implements, which can attach to the three-point hitches found on the rear of most tractors. This type of mower is best used to provide a rough cut to long grass and even brambles in locations such as roadsides, where contact with loose debris may be possible.

Roths Industries, Inc. (1945–1960) was a manufacturer of small garden tractors and other agricultural equipment founded by Herbert C. Roths in Alma, Michigan. The company manufactured Garden King Walking Tractors, BesRo Riding Tractors, and Till Ro Stalk Cutters.

<span class="mw-page-title-main">Drag harrow</span>

A drag harrow, a type of spring-tooth harrow, is a largely outdated type of soil cultivation implement that is used to smooth the ground as well as loosen it after it has been plowed and packed. It uses many flexible iron teeth usually arranged into three rows. It has no hydraulic functionality and has to be raised/adjusted with one or multiple manual levers. It is a largely outdated piece of farm equipment, having been replaced by more modern disc harrows and hydraulically operated field cultivators.

<span class="mw-page-title-main">Disc harrow</span> Farming equipment

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 chop up unwanted weeds or crop residue.

<span class="mw-page-title-main">Spring-tooth harrow</span>

Harrows, whether spring tooth, spike tooth or disc harrows can have a drag connection or have a 3 point mounting. A drag harrow is pulled and cannot be backed up. Three point implements can be raised and lowered hydraulicly and maneuvered more easily. A spring-tooth harrow is a type of harrow, and specifically a type of tine harrow. It uses many flexible iron teeth mounted in rows to loosen the soil before planting.

This glossary of agriculture is a list of definitions of terms and concepts used in agriculture, its sub-disciplines, and related fields, including horticulture, animal husbandry, agribusiness, and agricultural policy. For other glossaries relevant to agricultural science, see Glossary of biology, Glossary of ecology, Glossary of environmental science, and Glossary of botanical terms.

References

  1. Jean-Martin Fortier. "The rotary power harrow" Archived 2015-02-14 at the Wayback Machine , FarmStart Tool Shed, February 18, 2014. Retrieved on 5 March 2015.
  2. Jean-Martin Fortier. "The rotary power harrow" Archived 2015-02-14 at the Wayback Machine , FarmStart Tool Shed, February 18, 2014. Retrieved on 5 March 2015.
    • White, K. D. (1967), Agricultural Implements of the Roman World, Cambridge University Press, pp. 146ff
  3. Jean Gimpel. The Medieval Machine. p. 53.