Which type of spreader uses a rotating impeller for distribution?

A rotary spreader utilizes a rotating impeller to distribute fertilizer or other granular materials evenly over a designated area. This mechanism allows the material to be flung outward in a broad pattern, covering a wider area compared to other types of spreaders. The rotating impeller creates a centrifugal force that propels the product forward, providing effective and efficient application over larger spaces.

In contrast, a pendulum spreader operates differently by swinging a hopper back and forth, which allows for a more controlled drop of materials directly underneath it. A drop spreader, similarly, releases materials directly downwards through a chute, resulting in a precise application but limited distribution width. A broadcast spreader may sound similar to a rotary spreader, but it typically reflects a broader category that includes rotary types and may not exclusively use the impeller mechanism for spreading.

Overall, the characteristic of the rotating impeller specifically defines how a rotary spreader functions, leading to its designation as such within the options provided.