Row Crop is the term used to refer to the practice of growing some crop types in regular spaced rows. A lot of vegetable and salad crops are grown in this way.
A Oliver 70 tractor with rear wheels set to wide track, and a tricycle front wheel
The machinery used to sow, cultivate and harvest these crops are also referred to as Row crop machinery. The main factor with most of the machinery is the ability to adjust the wheel track width to suit the row spacings of different crop types. Some tractor types had special axles that allowed the wheels to be slid in and out. Others also had a cntraly mounted front wheel (or pair of close coupled wheels) to allow easier turning into rows on the headland.