threshing

Threshing is the agricultural process of separating the edible grain from the husks, chaff, and straw that surround it in cereal crops. It generally follows harvest when the grain heads have been gathered and dried. The outcome is grain that can be cleaned, stored, and milled.

Traditionally, threshing was done on a hard surface known as a threshing floor. A flail—a short baton attached to a chain or strap—was used to strike or beat the bundles, loosening the kernels. In some systems, animals or people would tread on the sheaves. A threshing board or tribulum, a flat plank embedded with stones or flints, might be dragged across the grain to loosen kernels.

Mechanization and modern practice have greatly increased efficiency. Threshing machines use beating, rotating cylinders, and sieves to detach kernels and separate chaff. In contemporary agriculture, the combine harvester performs harvesting, threshing, cleaning, and collection in one integrated operation, reducing the need for separate threshing steps.

Winnowing follows threshing to separate lighter chaff from the heavier grain. This is often accomplished with wind or a fan, sometimes aided by screens or sieves to remove remaining debris.

Threshing is employed for crops such as wheat, barley, oats, rye, maize, and rice. Practices vary by region and crop, but the basic purpose remains the same: to release edible grain from the surrounding plant material for storage and processing.