Rotary Mower

A rotary mower’s defining feature is its horizontally spinning blades or discs, which cut by impact rather than the shear action used by sickle-bar mowers. This makes it well suited to cutting lodged, dense, or uneven stands with less risk of blockage.

1. The mower is towed or mounted and driven via the tractor power take-off
2. Blades or discs spin at high speed close to ground level
3. Standing forage is cut as it passes beneath the rotating cutting elements
4. Cut material is laid into a swath or windrow behind the mower
5. Some models pass the cut material through rollers or flails (a conditioner) to speed drying

Mowing is the first step in producing hay or silage from a standing forage crop, initiating the field-curing process that precedes raking and baling. Cutting height and timing relative to the crop’s growth stage influence both the yield and quality of the cut material and the speed and vigour of regrowth.

Outside forage harvest, rotary mowers are also used to top pastures — cutting mature or rejected growth to encourage fresh regrowth — and to maintain non-cropped areas such as field margins.

Disc mower

Uses multiple small rotating discs, each carrying two or more free-swinging blades

Drum mower

Uses larger rotating drums with blades mounted around the circumference

Mower-conditioner

Combines cutting with a conditioning stage that crushes or crimps stems to speed field drying

Cutting height affects both forage quality (lower cuts can include more stem and soil contamination) and stand persistence (very low cutting can damage crown tissue in some perennial forages). Blade condition and ground speed also influence cut quality.