Threshing and Winnowing

Threshing

Once a crop like wheat or paddy is harvested, the stalks are dried in the sun. The grains are attached to these dry stalks. Plucking grains one by one (like picking mangoes) is impossible because there are thousands of grains!

Definition: The process of beating stalks to separate the grains from them is called threshing.

Methods of Threshing

1. Manual: Farmers hold a bundle of stalks and beat them against a hard surface (like a wooden log or rock). The impact loosens the grains.
2. Bullocks: In traditional methods, bullocks trample over the stalks.
3. Machines: Modern technological developments have led to threshers, machines that separate grains from stalks and husk quickly.

Winnowing

After threshing, we get a mixture of grains and husk (the dry outer covering). We need to separate them. Since grains are heavier than husk, we use the property of weight and wind.

Definition: The method of separating heavier and lighter components of a mixture by wind or blowing air is called winnowing.

The Process

1. The farmer stands on a raised platform.
2. The mixture is placed in a soop (winnowing basket) or plate.
3. The farmer tilts the basket and lets the mixture slide down slowly.
4. The Wind acts:
   • The heavy grains fall vertically straight down to form a heap.
   • The light husk is blown away by the wind and forms a heap at a distance.

Visualization of Winnowing

The separated husk is often used as fodder for cattle, while the grain is stored for food.