- Also spelled:
- plough
- Key People:
- John Deere
Plow
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What is a plow used for in agriculture?
The plow is the most important agricultural implement and has been since the beginning of agriculture. It is used to turn and break up soil, bury crop residues, and aid in weed control.
Tillage is the manipulation of the soil into a desired condition by mechanical means. Soil is tilled to change its structure, kill weeds, and manage crop residues.
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How does a plow help prepare soil for planting?
The plow is an important agricultural tool used to prepare soil for planting by turning and breaking it up, which helps manage weeds and bury crop residues.
Tilling soil, which involves mechanical processing, is essential for creating the right physical conditions for planting, such as changing soil structure to improve water intake, storage, and transmission, and to provide a good environment for seeds and roots. Plowing can improve soil structure if done when the moisture content is optimum.
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What are the main parts of a traditional plow?
The traditional moldboard plow consists of three main parts:
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The share, which is a broad blade that cuts through the soil.
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The moldboard, which turns the furrow slice (the ribbon of soil that is cut and thrown to one side). Different soils require different-shaped moldboards to give the same degree of pulverization of the soil.
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The landside, which is a plate on the opposite side from the moldboard that absorbs the side thrust of the turning action. It is the side of a furrow next to the land in plowing.
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How have plows changed from ancient times to today?
From ancient digging sticks to today's tractor-drawn plows, plows have undergone significant advancements. Early plows were simple digging sticks with handles. By Roman times, plows with iron blades were used, but they were unable to handle the heavier soils of northwestern Europe. The introduction of the wheeled plow facilitated the spread of European agriculture northward.
John Deere's all-steel plow in the mid-19th century was a pivotal invention, enabling farmers to cultivate more land with less effort. Modern plows include moldboard, disk, rotary, chisel, and subsoil plows, each designed for specific soil conditions and purposes. Today’s plows are often connected to tractors and can have multiple bottoms for increased efficiency.
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What are the differences between animal-drawn and machine-powered plows?
Animal-drawn plows and machine-powered plows represent a significant evolution in agricultural technology. Animal-drawn plows, like those used in Roman times, were light and typically had iron blades, suitable for topsoil but less effective for heavier soils. The wheeled plow, initially drawn by oxen and later by horses, facilitated agricultural expansion in Europe.
In contrast, machine-powered plows, particularly after the introduction of the gasoline engine, are tractor-drawn and can have multiple hydraulically lifted bottoms. John Deere's 19th-century all-steel plow was designed to handle the tough prairie soils of the American Midwest, marking a major advancement in plow technology. Modern plows include disk plows for hard or rocky soils and rotary plows for creating seedbeds.
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How does plowing affect soil health and crop growth?
Plowing, a form of tillage, involves mechanical soil processing to prepare it for planting by modifying its structure, managing crop residues, and eliminating weeds.
When timed correctly with optimal moisture content, the loosening and granulating effects of plowing can improve soil structure. However, if not properly timed, plowing can create an unfavorable structure. Intensive tillage can break down soil structure, making it susceptible to crusting, reduced water intake, increased runoff, and decreased water storage for crops.
Conventional plowing may create a hardpan, which is a compacted layer that reduces crop yields. The concept of minimum tillage is usually desirable because intensive tillage breaks down soil structure.
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Plow, most important agricultural implement since the beginning of history, used to turn and break up soil, to bury crop residues, and to help control weeds.
History and development
The antecedent of the plow is the prehistoric digging stick. The earliest plows were doubtless digging sticks fashioned with handles for pulling or pushing. By Roman times, light, wheelless plows with iron shares (blades) were drawn by oxen; these implements could break up the topsoil of the Mediterranean regions but could not handle the heavier soils of northwestern Europe. The wheeled plow, at first drawn by oxen but later by horses, made possible the northward spread of European agriculture. The 18th-century addition of the moldboard, which turned the furrow slice cut by the plowshare, was an important advance. In the mid-19th century the black prairie soils of the American Midwest challenged the strength of the existing plow, and American mechanic John Deere invented the all-steel one-piece share and moldboard. The three-wheel sulky plow followed and, with the introduction of the gasoline engine, the tractor-drawn plow.
Plow types
In its simplest form the moldboard plow consists of the share, the broad blade that cuts through the soil; the moldboard, for turning the furrow slice; and the landside, a plate on the opposite side from the moldboard that absorbs the side thrust of the turning action. Horse-drawn moldboard plows, which are no longer commonly used, have a single bottom (share and moldboard), while tractor-drawn plows have from 1 to 14 hydraulically lifted and controlled bottoms staggered in tandem. Listers and middlebusters are double-moldboard plows that leave a furrow by throwing the dirt both ways.
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Disk plows usually have three or more individually mounted concave disks that are inclined backward to achieve maximum depth. They are particularly adapted for use in hard, dry soils, shrubby or bushy land, or on rocky land. Disk tillers, also called harrow plows or one-way disk plows, usually consist of a gang of many disks mounted on one axle (see harrow). Used after grain harvest, they usually leave some stubble to help reduce wind erosion and often have seeding equipment. Two-way (reversible) plows have disks or moldboards that can be either opposed, so that one fills the trench made by the other, or set to throw the soil entirely to the right or left.
Rotary plows or tillers (sometimes called rototillers) have curved cutting knives mounted on a horizontal power-driven shaft. The pronged rotary hoe, a plow used chiefly for seedbed and weed control, works well at high speed. Garden sizes cut swaths from about 0.3 to 0.8 metre (1 to 2.5 feet) wide; tractor types, more than 3 metres (10 feet).
Deep tillage implements, used chiefly to break up hardpan and packed soils, include the subsoiler and the chisel plow. The subsoiler must be pulled by a heavy tractor, for its steel-pointed shank is capable of penetrating the subsoil to a depth of nearly one metre (three feet). The chisel plow, or ripper, has several rigid or spring-toothed shanks with double pointed shovels mounted on a transverse bar at intervals of 0.3 to 0.9 metres (one to three feet). Plowing depths vary from shallow to a half metre (1.5 feet).