When tractors were introduced, they were a great relief to farmers. They were found to be more economical to use as compared to keeping animals for tillage. Tractors are most useful for the cultivation purposes and they are a must for farm owners. Apart from cultivation, they are used in excavation, in manufacturing industry, or at the construction sites. Farm size, availability of labor, crop selection, custom services, and cultural practices such as choice of tillage system, all affect the choice of a flawless set of equipment and ultimately, the number of tractors necessary to farm. The demand for tractors has increased with time.
The tractors are designed to operate at different travel speeds. Their engine ranges from 112 to 120 horsepower or more. Over the years, the tractors have improvised a lot and now they are offered in the range of 20 to 400 horsepower. Engine power is transmitted to a gearbox typically having 4 to10 speeds, and through the differential gear to the two large rear-drive wheels. Some farm tractors can reach speeds up to 25 mph. At the same time, slow speeds are necessary to give the farmer more control while doing field work. The tractors require large tires to avoid compressing the earth and to avoid digging in. Hence, the rear tires are large and the front tires need to be small and smooth, unless the tractor has a four wheel drive.
Tractors are used to pull, or in some cases, push objects. They are designed to pull either large loads at slow speeds or lighter loads at higher speeds. Field speeds up to 10 mph are typical, but rangeland applications usually vary from 2 to 5 mph. Tractors can be generally classified as two-wheel drive, two-wheel drive with front wheel assist, four-wheel drive (often with articulated steering), or track tractors (with either two or four powered rubber tracks). Also available are the small tractors for sale (http://www.heavyequipmentregistry.com/) that are usually used for cultivation purposes.