Harrows are tools for cultivation of land and come in several major types: disc harrows, chain harrows and the less frequently used spike and spring tine harrows. All these differ in design, construction and the functions they perform. Also, there is a great variety of models within each harrow type, which is easily explained with their long-lived service to humanity (since about 2500 BC) and almost universal spreading: different harrow types have been used on all continents except, of course, Antarctica. Read the guide below to compare the make-up and functions of the two most popular harrows types: the disc and the chain ones.
Construction of the Disc Harrow
Disc harrows are usually made of a solid metal frame or shaft to which a different number of discs are attached. The shape and diameter of the discs depend on the purposes for which the particular harrow is intended. Typically, the discs will have a different degree of concavity. They will be offset at a sharp angle relative to the direction in which the propelling vehicle is going. There are disc harrow models which are outfitted with several rows of wheels, either only at the front or the back of the vehicle, or at both of its ends. In the past, disc harrows were drawn by horse pairs, but nowadays, they are almost exclusively dragged by tractors or some other agricultural motor vehicle.
Construction of the Chain Harrow
This type of harrow consists of a chain mesh which has spikes, teeth or hooks at its nodes. It is fastened behind a steel bar or spread inside an iron frame. Unlike disc harrows, this chain type can be mounted only at the back of the driving vehicle. Chain harrows are typically more lightweight than the disc ones and get damaged more easily when not used according to the manufacturer’s instructions.
Functions of the Disc Harrow
Common uses of the disc harrow includes:
- Breaking up large clumps or sods of plowed soil
- Uprooting bigger weeds
- Chopping up stumps and stubbles of old plants, such as wheat, rye and corn to prepare the land for plowing and prevent the plough from getting clogged
- Turning out the soil to increase its health and mixing it up with fertilizers for greater productivity
- Leveling out uneven agricultural terrains
In general, the disc harrow is utilized for more heavy-duty works than its chain counterpart.
Functions of the Chain Harrow
Among the operations that the chain harrow is used to perform are:
- Leveling the tilth after plowing
- Breaking up lighter clumps and sods into finer lumps
- Covering up the newly planted seeds
- Spreading out and chopping up dung and other larger fertilizers on pastures and other farm lands
- Leveling sports fields after games by smoothing out boot traces and removing imprints
In the typical case, chain harrows are rarely used alone to cultivate land. Most often, they are utilized in combination with a plough and some other harrow type.