What is winnowing? Describe this method.

Hint:
The word has a simple meaning it means to blow. As we have to write in scientific terms, it means to clean the grains by blowing wind through grain falling from a certain height. The source of wind can be artificial or it can be natural.

Complete step by step solution
Wind winnowing: It is an agricultural method which is developed by our ancestors for separating grain from pods. It is also used to remove small beetles or other pests from stored or cultivated grain. Threshing is the first step that comes before winnowing in the pod removal process in the separation of grain or seeds from the husks and straw.

Winnowing the pods or seed cover is a general term used. It involves throwing mixture from a certain height into the air so that the heavier grains fall back to the earth due to gravity which is clean and can be recovered and the wind blows away the useless lighter chaff.

This technique includes using an apparatus called winnowing fan (a shaped basket shaken to raise to and for in the air by using manual force of -hands to separate lighter pods) or using a tool (a winnowing fork or shovel) on a pile of harvested grain.

It is the process of separating clean grains from pods, it is one of the important and major process uses for the cultivation of paddy. Wind is blown for long hours and the process is repeated as per the requirement.

Note:
In this separation method, fan is generally used and the process is done in the open fields instead of a closed industrial room hence the weather condition plays a major role to follow the process, it cannot be done in the rainy season.