1. Crop Production And Management SCIENCE class 8 in English Medium ncert book solutions Chapter Review

Chapter Review:

• Plants of the same kind are grown and cultivated at one place on a large scale, it is called a crop.
• Khurpi, sickle, shovel, plough, etc. are some agricultures tools.
• Crops are of different types like cereals, vegetables and fruits.
• According to season there are two type of crops – (i) Rabi crops and (ii) Kharif Crops.
• Rabi crops are wheat, gram, pea, mustard and linseed.
• Paddy, maize, soyabean, groundnut, cotton, etc., are kharif crops.
• The process of loosening and turning of the soil is called tilling or ploughing.
• The levelling of soil is done with the help of a leveller.
• Nowadays ploughing is done by tractor driven cultivator.
• The use of cultivator saves labour and time.
• The substances which are added to the soil in the form of nutrients for the healthy growth of plants are called manure and fertilisers.
• Manure is an organic substance obtained from the decomposition of plant or animal wastes.
• Rhizobium bacteria are present in the nodules of the roots of leguminous plants.
• Rhizobium bacteria fix atmospheric nitrogen.
• A fertiliser is an inorganic salt which is prepared in factories.
• Fertilisers are very rich in plant nutrients like nitrogen, phosphorus and potassium.
• The supply of water to crops at different intervals is called irrigation.
• The sources of irrigation are— wells, tubewells, ponds, lakes, rivers, dams and canals.
• The traditional ways of irrigation are moat, chain pump, Dhekali and Rahat.
• Modern methods of irrigation help us to use water economically.
• Modern methods of irrigation are sprinkler system and drip system.
• These undesirable plants are called weeds.
• The removal of weeds is called weeding.
• Weeds are also controlled by using certain chemicals, called weedicides, like 2,4-D.
• The cutting of crop after it is mature is called harvesting.
• The grain seeds need to be separated from the chaff. This process is called threshing.