Question

Define harrow.

Answer 1

Hint: Let’s start by the word- Harrowing, which is often carried on fields to follow up the rough finish left by plowing operations. The purpose of doing so is generally to break up the clods (or lumps of soil) and to give a finer finish, soil structure or a good tilth that is suitable for seedbed use. Also, The Coarser harrowing can also be used for removing weeds and to cover the seed after sowing. You must know, Harrows can differ from cultivators in ways that disturb the whole soil surface.

Complete answer:
Harrow, a machine which has large rollers attached and used to spread the soil particles evenly and also used to break the rocks in the agricultural field.
Remember, it is different from a ploughing machine as it does not dig into the soil. An implement of agriculture, usually is formed by pieces of timber or metal which cross each other, and set with wooden teeth or iron . Harrow is drawn over plowed land to level it and also to break the clods, stir the soil and to make it fine, or to cover seed when sown.

We have four general types of harrows: Tine harrows (including spring-tooth harrows, disc harrows, drag harrows, and spike harrows), chain-disk harrows, and chain harrows.

Harrows were originally drawn by the draft animals, like horses, mules, or oxen, or in some places by manual labourers. But in modern practice, are almost always tractor-mounted implements, either trailed after the tractor by a drawbar or mounted on the three-point hitch. Note that, modern development of traditional harrow is the rotary power harrow, also called a power harrow

Additional information:
A rotary power harrow, or simply power harrow, contains multiple sets of vertical tines.
Every set of tines is rotated on a vertical axis and tills the soil horizontally. As a result, unlike a rotary tiller, soil layers don’t turn over or invert, which is useful in preventing dormant weed seeds from being brought to the surface, and no horizontal slicing of the subsurface soil that can lead to hardpan formation.

Note: In cool climates, widely used types are : the chain harrow, ,the disc harrow, the time or spike harrow and spring tine harrow. Also, there are many types of power harrow, in which cultivators are driven by power from the tractor rather than on its forward motion. Chain harrows are often used for lighter works, such as levelling the tilth or covering seed. On the other hand, disc harrows are generally used for heavy work, such as following ploughing to break up the soil.