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Class 8 Science Chapter 1 Extra Questions and Answers Crop Production and Management
Crop Production And Management Class 8 Extra Questions Question 1.
Name two methods for control weed.
- Weeds are removed by hand uprooting.
- Weeds are removed by using weedicides.
Crop Production And Management Class 8 Extra Questions And Answers Question 2.
Choose the correct option and rewrite the sentence again. Weeding/Feeding is the process of removal of weeds.
Weeding is the process of removal of weeds.
Class 8 Science Chapter 1 Extra Questions And Answers Question 3.
What is the process of loosening and turning of the soil called?
Tilling or ploughing.
Class 8 Science Ch 1 Extra Questions Question 4.
What are the big pieces of soil in the ploughed field called?
Crop Production And Management Extra Questions Question 5.
Name the main tools used for ploughing?
Plough, hoe, and cultivator.
Class 8 Science Chapter 1 Extra Questions Question 6.
What is meant by good quality seeds?
It means clean and healthy seeds that yield good crops both in quality and quantity.
Extra Questions For Class 8 Science Chapter 1 Question 7.
What name is given to the manure obtained from plant and animal waste?
Crop Production And Management Extra Questions And Answers Question 8.
Name the chemical substances which are rich in a particular nutrient?
Crop Production And Management Class 8 Important Questions Question 9.
Name the bacterium present in the nodules of the roots of leguminous plants which fixes atmospheric nitrogen.
Class 8 Crop Production And Management Extra Questions Question 10.
Name the process of supply of water to crops at different intervals?
Crop Production And Management Questions And Answers Pdf Question 11.
What are two latest irrigation methods that help us to use water economically?
Sprinkler system and Drip system.
Crop Production And Management Class 8 Questions And Answers Question 12.
What do we call the undesirable plants which grow along with the main crop unpurposely?
Extra Questions Of Chapter 1 Science Class 8 Question 13.
What is the best time for the removal of weeds?
Before they produce flowers and seeds.
Crop Production And Management Class 8 Extra Question And Answers Question 14.
What are the chemicals used to control weeds Called? Give one example.
Weedicides e.g., 2 and 4-D.
Crop Production And Management Class 8 Questions Question 15.
Name some traditional methods to irrigate the field.
The various traditional ways to irrigate the fields are :
- Moat (pulley system),
- Chain pump,
- Dhekli (lever system),
Why is weeding necessary?
Weeding is necessary since weeds compete with the crop plants for water, nutrients, space and light.
What is combine and what is its use?
Combine is a combined harvester and thresher used for harvesting and threshing.
Explain the term harvesting. How is it done?
Harvesting is cutting the crop after they are matured. It is done either by manually or by machine called harvester.
How do we store foodgrains?
- Dried neem leaves are used for storing food grains at home.
- For storing large quantities of grains in big godowns, specific chemical treatments are done to protect foodgrains from pest and microorganisms.
What precautions are undertaken before storing the foodgrains?
Precautions undertaken before storing foodgrains are :
- Grains should be dried properly.
- Proper chemical treatment should be done to protect grains from insects, pests and microorganisms.
Mention any six agricultural practices.
The activities or tasks are used as agricultural practices are listed below :
- Preparation of soil
- Adding manure and fertilisers
- Protecting from weeds
Why storage of food grains are essential? Name two structures for storage of grain.
Storage of produce is an essential task. The harvested grains are to be kept safe from moisture insects, rats and microorganisms. Harvested grains have more moisture. So the grains are properly dried in the sun to reduce the moisture in them. This prevents the attack by insect pests, bacteria and fungi.
Methods of storing grains :
- Farmers store grains in jute bags or metallic bins.
- Large scale storage of grains is done in silos and granaries.
Describe the use of seed drill.
The seed drill is used for sowing seeds with the help of tractors. This tool sows the seeds uniformly at a proper distance and depth and cover seeds by soil. This prevents damage caused by birds and also saves time and labour.
How is organic manure prepared?
For preparing manure, plant and animal waste is dumped in pits at open places and allowed to decompose. The decomposition is facilitated by some microorganisms. The decomposed matter is called organic manure.
Why is the organic manure considered better than fertilizers?
The organic manure is considered better than fertilizers because :
- it enhances the water holding capacity of soil.
- it makes the soil porous due to which exchange of gases becomes easy.
- it increases the number of friendly microbes.
- it improves the texture of the soil.
What is crop rotation? What is its advantage?
The crop rotation is replenishment of soil with nutrients by avoiding the cultivation of the same crop year after year. It can be done by growing another crop alternately.
What is the benefit of irrigation?
When crops are irrigated, nutrients get dissolved in water and get transported to each part of the plants along with water.
What are fertilizers and manure? How are they produced? How are they different from one another?
The substances which are added to the soil in the form of nutrients for the healthy growth of plants are called manure and fertilizers. Fertilizers are chemical substances which are rich in a particular nutrient. These are produced in factories. Manure is an organic substance which is obtained from the decomposition of plant and animal wastes.
A fertilizer is different from manure in the following ways :
|(i) Fertilizers are prepared in the factories.||Manure is prepared in the fields.|
|(ii) Fertilizers do not provide any humus to the soil.||Manure provides a lot of humus to the soil.|
|(iii) Fertilizers are very rich in plant nutrients like nitrogen, phosphorus and potassium.||Manure is not very rich in plant nutrients.|
|(iv) Fertilizer is an inorganic substance.||Manure is a natural substance obtained by the decomposition of cattle dung, human waste and plant residues.|
(a) Why does farmer follow crop rotation practice in his field?
(b) What will happen if a farmer does not plough his. field before sowing the seeds? Write any two effects.
(a) Crop rotation is done by growing legume crops and cereal crops like wheat alternately on the same piece of land. Rhizobium bacteria present in the nodules of the roots of leguminous plants helps in the replenishment of the soil with nitrogen. They fix atmospheric nitrogen.
(b) When a farmer doesn’t plough his field before sowing, this may have the following effects :
- Ploughing helps in proper mixing of manure in the soil and turning the soil over.
- Ploughing helps the water to go penetrate through the soil and reach the roots.
- Ploughing improves air circulation so that roots can respire easily.
- Ploughing improves the water-retaining capacity of the soil.
(a) What are fertilizers?
(b) Write any two disadvantages of using fertilizers excessively.
(a) A fertilizer is an inorganic salt prepared in factories. Fertilisers are very rich in plant nutrients like nitrogen, phosphorus and potassium (NPK), urea etc.
- Fertilisers are becoming a source of water pollution.
- Excessive use of fertilisers makes the soil less fertile.
- Long-term use of chemical fertilizer changes the nature (pH) of the soil.
- Excessive application of fertilizers affects the environment negatively.
Multiple Choice Questions (MCQs)
1. Hoe is an agriculture tool for
(а) Removing weeds
(b) Loosening of soil
(c) Both (a) and (b).
(b) Loosening of soil.
2. The process of loosening and turning of soil is called
(a) irrigation and manuring
(b) digging and winnowing
(c) tilling and ploughing
(d) harvesting and storage.
(a) irrigation and manuring.
3. Whifeh irrigation system is best suited to avoid wastage of water?
(a) Drip system
(b) Chain pump
(d) Pulley system.
(b) Chain pump.
4. Combine in an agriculture tool for