Straw & Chaff Spreading

Most combines today spread straw only about 15 to 25 feet . This is narrower than the width of cut most combines can handle. The Prairie Agricultural Machinery Institute says farmers should be concerned with getting straw evenly spread. While choices include sizing the cutting width and purchasing specialized choppers, many farmers have adapted or improved the existing choppers and spreaders on their own combines. PAMI suggests that farmers can do the following to improve existing straw chopper performance. make sure concave knives are sharp and the flails are square Dull knives and rounded flails reduce cutting effectiveness and use extra power. on many combines, using larger deflector fins will give a wider spread

Chaff spreading is usually accomplished by adding a spreader below and behind the sieves. Spreaders are either mechanically or hydraulically driven. Most spreaders move the chaff mechanically using paddles - others use air. Some spreaders must be used in conjunction with a deflector to move chaff from sieves to spreader. In summary, things to look for in a chaff spreader are: ~ low power requirements ~ reasonable uniformity in spread ~ ability to check losses and access adjustments for the cleaning shoe