NCERT Solutions - Crop Production & Management - Notes | Study Science Class 8 - Class 8

Q1. Select the correct word from the following list and fill in the blanks. 
(float, water, crop, nutrients, preparation)
(a) The same kind of plants grown and cultivated on a large scale at a place is called ______.
Ans: The same kind of plants grown and cultivated on a large scale at a place is called the crop.
(b) The first step before growing crops is ______ of the soil.
Ans: The first step before growing crops is the preparation of the soil.

Preparation of Soil(c) Damaged seeds would ______ on top of water.
Ans: Damaged seeds would float on top of the water.
(d) For growing a crop, sufficient sunlight and ______ and ______ from the soil are essential.
Ans: For growing a crop, sufficient sunlight and water and nutrients from the soil are essential.

Q2. Match items in column A with those in column B. Ans: 
Q3. Give two examples of each.
(a) Kharif crop
(b) Rabi crop
Ans:
(a) Paddy and maize(b) Wheat and gram

Q4. Write a paragraph in your own words on each of the following:
(a) Preparation of soil
(b) Sowing
(c) Weeding
(d) Threshing
Ans: 
(a) Preparation of soilPreparation of Soil

• Preparation of soil is the first step in farming. Soil is loosened and turned over. This helps in making the soil more airy so that roots can breathe in air. 
• Moreover, loosening of soil also facilitates better penetration of roots into the soil. Seeds can be easily shown in loosened soil.

(b) SowingSowing

• The method of putting the seeds into the soil is called sowing. Traditionally, the seed is sown manually by spreading the seeds by hand.
• This process is called broadcasting. Seed drills are used when sewing needs to be done on a large scale.

(c) WeedingWeeding

• Removal of weeds is called weeding. Unwanted plants which grow along with the crop are called weeds. 
• They compete for resources; like sunlight, water, and air; with the main crop. So, it is necessary to remove weeds for the proper growth of crops. 
• Weeding is usually done manually by using hands and sickles. Sometimes weedicides are also sprayed.

(d) Threshing 
Threshing

• Separation of grains from harvested stems is called threshing. For smaller quantity, threshing is done by hands. For a somewhat bigger quantity, threshing is done using animals, especially bullocks. 
• Animals are made to trample over the harvested stock, which helps in the separation of grains. Threshing machines are used for bigger quantities.

Q5. Explain how fertilizers are different from manure.
Ans: 

• Fertilizers are synthesized in factories from inorganic materials. 
• On the other hand, manure is made from organic materials; through the process of decomposition. 
• Excessive use of fertilizers is not good for the soil and may lead to soil pollution. Use of manure is beneficial for soil.

Q6. What is irrigation? Describe two methods of irrigation that conserve water.
Ans: The process of artificially providing water to growing crops is called irrigation.
Two methods of irrigation that help in water conservation are as follows:Sprinkler System

• Sprinkler: Sprinkler system is composed of pipelines in which nozzles are fitted at various locations. Water comes out of the nozzle and is sprinkled on plants. This system helps in saving a lot of water.Drip Irrigation
• Drip Irrigation: For this, small holes are made in pipes that are laid along the rows of crops. Water slowly drips down on the roots of crops. This system is especially useful for plantations and also in water-scarce areas.

Q7. If wheat is sown in the Kharif season, what would happen?
Ans: 

• The crop of wheat needs mild to moderate temperature and frost-free days; along with irrigation but no waterlogging. Winters are suitable for growing wheat.
• In the Kharif season; which coincides with the peak summer months in India, the temperature is at its peak which is not suitable for wheat.
• Moreover, during rainy season lot of water accumulates in fields which would be harmful to the wheat crop. Hence, if wheat is sown in the Kharif season; the productivity would be minuscule and would not be profitable for the farmers.

Q8. Explain how soil gets affected by the continuous plantation of crops in a field.
Ans: Continuous plantation of crops in a field affects soil fertility. Plants utilize all the nutrients from soil which leads to depletion of nutrients in the soil. As a result, soil fertility reduces drastically.

Q9. What are the weeds? How can we control them?
Ans: 

• Unwanted plants which grow along with crops are called weeds. 
• Weeds compete with crops for natural resources; like sunlight, water, and nutrients. Thus, weeds hamper the growth of crops. 
• Weeds are usually removed manually by hands and by sickles. This process is called weeding. Sometimes, weedicides are also sprayed to kill weeds.

Q10. Arrange the following boxes in the proper order to make a flow chart of sugarcane crop production.

Ans: Preparation of soil → Ploughing the field → Manuring → Sowing → Irrigation → Harvesting → Sending crop to the sugar factory.

Q11. Complete the following word puzzle with the help of clues given:

(a) Providing water to the crops.
(b) Keeping crop grains for a long time under proper conditions.
(c) Certain plants of the same kind grown on a large scale.
(d) A machine used for cutting the matured crop.
(e) A rabi crop that is also one of the pulses.
(f) A process of separating the grain from the chaff.
Ans: 

(a) Irrigation
(b) Storage
(c) Crop
(d) Harvester
(e) Gram
(f) Winnowing