Rotary spreaders are used to broadcast seed, fertilizer, or other granular products. They consist of a hopper with an adjustable gate opening to regulate the flow of material falling onto a rotating spinner. Spreader size can vary from small hand-held units to large tractor mounted units. Units of 1- to 2-bushel capacity are powered by a 12-volt electric motor and can be mounted on ATVs or pick-ups. Three- to 32-bushel spreaders are attached to a tractor’s 3-point hitch and powered by the tractor’s power-take-off. Spreading rates vary from 3 to 1000 pounds/acre and swath width will vary between 20 and 40 feet. Some models have an agitator in the hopper to prevent blockages and provide a uniform flow of material.
Rotary spreaders are well suited for limited acreages on level or rolling terrain. Seed should be spread during or following the tilling operation. Spreaders can be attached directly to the tilling or mulching equipment. Fertilizer, seed only, seed blended with fertilizer, or lime may be applied on tilled soil or over pastures. Hand-operated units are not limited by type of terrain and are best suited for spot treatments. Rotary spreaders are simple and easy to use and maintain. They can be accurate, but are often misused, resulting in non-uniform applications. Tractor speed, flow rate, and swath width all affect the application rate; wind can distort the swath pattern.