23 September 2014

Harvest and Storage : Science Ncert

Harvest and Storage : Science Ncert / Cbse Revision Notes

As the crop matures, it has to be cut to collect the grains.

Harvesting: The process which involves cutting of mature crop to gather grains is known as harvesting.  
  • Harvesting can be done manually by using a sickle.  A sickle is a small instrument with sharp serrate-edged metal blade attached to a wooden handle.   
  • Harvesting can also be done by using a machine called as harvester.  
Harvest and Storage, Science Cbse / Ncert Revision Notes, class 8, Threshing


It is the process of separating the grains from the straw and chaff.
  • A thresher is used for threshing.
  • A combine is a combination of a thresher and a harvester.


It is a process of making natural wind to blow through the grains which allows the lighter substances to fly away leaving the heavier grains which fall on to the ground. Winnowing can be done manually. It can also be done by winnowing machine which has a fan to blow away the chaff.

Crop protection and storage:
  • Protection of crops against microorganisms, rodents, pests and moisture is done by drying in sun and exposing to fumes.
  • Silos are huge, air-tight cylindrical structures used to store grains.
  • Granaries are large rooms built above ground level to prevent rodents and pests from getting near the grains.
  • In cold storage, vegetables and fruits are stored at low temperatures.

Animal husbandry

Rearing and breeding livestock on a large scale to obtain food and other products from them. It includes dairy farming, poultry farming, pisciculture, sericulture, piggery etc.