When I think of a farm, I naturally think of a tractor. Every farm has a tractor. Most farmers have more than one. Even when I was a kid, farmers would have a “small” tractor for routine hauling and lifting jobs, and a bigger tractor for plowing, cultivating, and other heavy field work.
But in the early 20th century, most farms didn’t have any tractors at all. Farms were smaller, and the most of the work was done with horses or oxen. Tractors did exist, but they were specialist tools. They needed a different set of skills to maintain and operate, and they were quite costly. Since a typical farm only needed a tractor for a few days a year, it made more sense to pay someone to run their tractor than to buy your own.