- Harrow (tool)
agriculture, a set of harrows is an implement for cultivating the surface of the soil. In this way it is distinct in its effect from the plough, which is used for deeper cultivation. They are commonly called harrows (plural) as they are used as a set. There are nominally three types of harrows; disc (disk), tine and chain.
Harrows were originally horse-drawn. In modern practice they are almost always
tractor-mounted implements, drawn after the tractor, either trailed or mounted on the three-point linkage.
Harrowing is often carried out on fields to follow the rough finish left by ploughing operations. The purpose of this harrowing is generally to break up clods and lumps of soil and to provide a finer finish, a good tilth or
soil structurethat is suitable for seeding and planting operations. Such coarser harrowing may also be used to remove weeds and to cover seedafter sowing.
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.
Chain harrowing may 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. When used on tilled land in combination with the other two types, chain harrowing rolls the remaining larger clumps of soil to the surface where the weather will break them down and prevent interference with seed germination.
All three harrow types can be used in one pass to prepare the soil for seeding. It is also common to used 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 the intended purpose. They almost always consist of a rigid frame to which are attached discs, teeth, linked chains or other means of cultivation, but tine and chain harrows are often only supported by a rigid towing-bar at the front of the set.
In the southern hemisphere the so-called "giant discs" are a specialised kind of disc harrows that can stand in for a plough in very rough country where a mouldboard plough will not handle the tree-stumps and rocks, and a disc-plough is too slow (because of its limited number of discs). Giant discs are scalloped-edged discs operated 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 normally immediately followed by broadcast fertilisation and seeding, rather than drilled or row seeding.
A "drag" is a heavy harrow.
Europe, harrows were first used in the early Middle Ages.
The following text is taken from the "Household Cyclopedia" of 1881:
"When employed to reduce a strong obdurate soil, not more than two harrows should be yoked together, because they are apt to ride and tumble upon each other, and thus impede the work, and execute it imperfectly. On rough soils, harrows ought to be driven as fast as the
horses can walk; because their effect is in the direct proportion to the degree of velocity with which they are driven. In ordinary cases, and in every case where harrowing is meant for covering the seed, three harrows are the best yoke, because they fill up the ground more effectually and leave fewer vacancies, than when a smaller number is employed. The harrowman's attention, at the seed process, should be constantly directed to prevent these implements from riding upon each other, and to keep them clear of every impediment from stones, lumps of earth, or clods, and quickens or grass roots; for any of these prevents the implement from working with perfection, and causes a mark or trail upon the surface, always unpleasing to the eye, and generally detrimental to the vegetation of the seed. Harrowing is usually given in different directions, first in length, then across, and finally in length as at first. Careful husbandmen study, in the finishing part of the process, to have the harrows drawn in a straight line, without suffering the horses to go in a zigzag manner, and are also attentive that the horses enter fairly upon the ridge, without making a curve at the outset. In some instances, an excess of harrowing has been found very prejudicial to the succeeding crop; but it is always necessary to give so much as to break the furrow, and level the surface, otherwise the operation is imperfectly performed."
Roller (agricultural tool)
* [http://www.degelman.com/web%20pages/strawmaster.html "Degelman Strawmaster Harrows"] Tine Harrows
* [http://www.amiright.com/parody/60s/leapylee0.shtml "Little Harrows"] Song parody
* [http://www.martensmfg.com "Martens Harrows"] Spike harrows
* [http://www.pepinharrows.com "Pepin Harrows"] Spike & Coil Tine Harrows
* [http://www.maybridgeharrows.com "May-Bridge Harrows"] Chain harrows
* [http://commons.wikimedia.org/wiki/Category:Harrows Examples of harrows]
Wikimedia Foundation. 2010.
Look at other dictionaries:
Harrow — may be:Objects: *Harrow (tool), an agricultural implement consisting of many spikes, tines or discs dragged across the soil *Spike harrow, an agricultural harrow consisting of a series of downward pointing spikesPlaces: * London Borough of Harrow … Wikipedia
harrow — harÂ·row || hÃ¦rÉ™ÊŠ n. agricultural tool with spikes or disks for breaking up and leveling plowed ground earth v. break up and level plowed ground by means of a harrow; bother, harass … English contemporary dictionary
Roller (agricultural tool) — The roller is an agricultural tool used for flattening land or breaking up large clumps of soil, especially after ploughing. Typically, rollers are pulled by tractors or, prior to mechanisation, a team of animals such as horses or oxen.Flatter… … Wikipedia
Rake (tool) — imagestack A rake (Old English raca , cognate with Dutch raak , German Rechen , from a root meaning to scrape together, heap up ) is an agricultural and horticultural implement consisting of a toothed bar fixed transversely to a handle, and used… … Wikipedia
Roths Industries — Roths Industries, Inc. (1946 ndash;1958) was a manufacturer of small garden tractors and other agricultural equipment started by Herbert C. Roths in Alma, Michigan. The company manufactured Garden King Walking Tractors, BesRo Riding Tractors,… … Wikipedia
Chemical elements in East Asian languages — The names for chemical elements in East Asian languages, along with those for some chemical compounds (mostly organic), are among the newest words to enter the local vocabularies. Except for those metals well known since antiquity, most elements… … Wikipedia
Liste von Automobilmarken — Automobilmarken, kurz Automarken, sind die Handelsnamen, unter denen Automobil Hersteller Fahrzeuge vertreiben. Aufgelistet werden Hersteller von Pkw und Rennwagen, die Automobile gebaut haben, bauen oder bauen wollten. Nutzfahrzeuge werden in… … Deutsch Wikipedia
Antipsychotic — Advertisement for Thorazine (chlorpromazine) from the 1950s An antipsychotic (or neuroleptic) is a tranquilizing psychiatric medication primarily used to manage psychosis (including delusions or hallucinations, as well as disordered tho … Wikipedia
agriculture, origins of — Introduction the active production of useful plants or animals in ecosystems that have been created by people. Agriculture has often been conceptualized narrowly, in terms of specific combinations of activities and organisms wet rice production… … Universalium
Reynolds-Alberta Museum — The Reynolds Alberta Museum, in Wetaskiwin, Alberta, Canada, one of 18 provincially owned and operated historic sites and museums, honours the spirit of the machine . It traces the mechanisation of Alberta s transportation, aviation, agricultural … Wikipedia