Crop Production and Management - Class 8 NCERT Science - Solutions of CBSE Guess Questions

 

CBSE Class VIII - Chapter 1, NCERT Science

Crop Production and Management


Solutions of CBSE Guess Questions (1 – 2 Marks Questions)

Question.1: Why does every living organism need food?

Answer: Every living organism needs food to grow and perform various other activities and body functions.

Question.2: Where do we get our food from?

Answer: We get our food from plants and animals.

Question.3: What is crop?

Answer: When same types of plants are grown at a large scale, it is called crop.

Question.4: Name the factors controlling crop production.

Answer: Soil, water, sunlight and air.

Question.5: Based on factors required to grow plants, how many crop seasons are observed in India?

Answer: Broadly two crop seasons: Rabi & Kharif.

Question.6: What are crumbs?

Answer: Crumbs are big pieces of soil present in fields, which require tilling.

Question.7: Which agricultural tools are used for tilling?

Answer: Plough, Hoe & Cultivators.

Question.8: Who supplies mineral nutrients to plants?

Answer: Soil.

Question.9: Which manure is called Organic manure?

Answer: Manure obtained from the dead bodies of plants and animals.

Question.10: Name any two important fertilizers.

Answer: Urea, NPK (Nitrogen, Phosphorus, Potassium).

Question.11: What is a fallow?

Answer: An uncultivated field between two cropping is called a fallow.

Question.12: Which bacteria are present in the legumes of leguminous plants?

Answer: Rhizobium.

Question.13: What is harvesting?

Answer: Cutting of the crop after it is mature is called harvesting.

Question.14: How does reduction in moisture of newly harvested grains help in storage?

Answer: It prevents pests, insects, bacteria etc from attacking the grains.

Question.15: Name the places where grains are stored at large scale.

Answer: Granaries and silos.


Solutions of CBSE Guess Questions (2 – 3 Marks Questions)

Question.16: Write the names of various agricultural practices undertaken to produce a crop.

Answer: Following agricultural practices are performed to produce the crop:

1.       Soil preparation,
2.       Sowing,
3.       Adding manure and fertilizers,
4.       Irrigation,
5.       Protection from weeds,
6.       Harvesting &
7.       Storage.

Question.17: Why is the soil turned and loosened before seeds are sown?

Answer: The soil is turned and loosened during the process of ploughing. The ploughing loosens the soil particles and turn the soil of upper surface. This allows the nutrients from the dead organism to be released back in the soil and better penetration and absorption of nutrients by plant roots. 

Question.18: What is the role of water in production of crops?

Answer: Water is essential for all plants. Crops should get enough water at different stages of their growth. Different crops require different amount of water in the field. The wheat crop requires moderate amount of water at the time sowing, flowering, and ripening of crop. Therefore, crops should be irrigated properly according to their needs.  

Question.19: What are the different methods of irrigation?

Answer: Supply of water to crops at appropriate intervals is called irrigation. Various sources of irrigations are- wells, tube wells, ponds, lakes, rivers, canals etc. Different methods of irrigation are adopted on the basis of the soil types, size of the field, requirement of water by the crop and of course, the availability of water. Some of the traditional methods of irrigation include water supply through moat (Pulley-system), chain pump, dhekli and rahat (lever-system).
Modern methods of irrigation help us to use water most economically. Two such methods are- Sprinkler system and Drip system.

Question.20: What is humus? How is it formed?   

Answer: Humus is a kind of soil rich in nutrients. It is formed by the microbial action on dead decaying bodies of plants and animals. It’s generally formed on those spots where – there are dense layers of trees. The soil below it becomes dark having more number of pathogenic bacteria.

Question.21: Why does a farmer rotate crops in the field? (Crop-rotation)

Answer: If the same crop is grown in the field year after year, it will lead to the deficiency of certain minerals. It is due to this fact that the same crop requires same type of nutrients.
To solve this problem farmers are encouraged to grow one pulse crop in – between two cereal crops in the field. So the method of successive cultivation of different crops in an orderly manner on the same fields, in contrast to a one-crop-system or to haphazard crop successions is known as crop rotation. For example, growing legumes as fodder in one season and wheat in the next season. The roots of legumes have so many nodules which contain nitrogen fixing bacteria. These convert free atmospheric nitrogen into nitrates and increase the fertility of the soil. (Replenishing of soil with nitrogen)

Question.22: What safety measures are to be taken in handling pesticides and weedicides?    

Answer: Weedicides and pesticides are highly poisonous chemicals. They kill the pests. They can harm the human also. So, certain precautionary measures should be taken while spraying pesticides and weedicides.

·   They should be kept away from the reach of children.
·   They should not be inhaled while spraying. Gloves and mouth covers should be used while spraying them.
·   Hands should be washed properly after their use.

Question.23: Distinguish between pesticides and weedicides.

Answer: Weeds are controlled by using certain chemicals called weedicides. These chemicals don’t cause any damage to the crop.
Pesticides are the chemicals which are used to kill the pests growing on the crops. They kill the eggs and larvae of the insects.

Question.24: Why should the harvested grains is protected from moisture?

Answer: The harvested grains should be protected from moisture because of the following reasons:
a)       It promotes the growth of insects.
b)       Moisture helps in germination of seed.
c)       It promotes the growth of fungi.

d)       It speedily spoils the quantity and quality of grains.

Solutions of CBSE Questions (Objective type / Multiple Choice / True-False)

Question.1: Fill in the blanks:
a.         ____ is used for sowing of seeds.
b.         Loosening the soil is also called _____.
c.          ____ is the second agricultural practice.
d.         _____ and ____ are used to add nutrients in the soil.
e.         Manures are the ___ substances.
f.          ____ is a weedicides.
g.         ____ is the economical method of irrigation.
h.         Leaving field uncultivated is called ______.
i.           _____ is used to separate seed from the chaff.
j.          Crops sown in the rainy season are called ______.
Solution: a. seed drill, b. tilling, c. sowing, d. manures and fertilizers, e. organic, f. metachlor, g. drip irrigation, h. fallow, i. thresher, j. rabi crops.
Question.2: Write ‘True/False’ for the following statements:
a.         Many plants are first grown in kindergartens and then sown in fields.
b.         Seeds can only be sown by using seed drills.
c.          Earth worms are farmer friendly.
d.         Substances that kill pests are called weedicides.
e.         Cutting and gathering of mature crops is called harvesting.
f.   Process of beating grains to separate them crop plants is called winnowing.
g.         Excess use of fertilization is not good for crops & soil.
h.         Animals which provide us with eggs and flesh are called milch animals.
Solution: a-false, b-false, c-true, d-false, e-true, f-false, g-true, h-false

Further study - 
Class 8, Crop Production and Management - Chapter 1, Science - NCERT Answers of Textbook Exercise [Read

CBSE Guess - 8th NCERT Science, Crop Production and Management – long answer questions [Read]

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