CBSE Class 8 Science Advanced Biology Crop Production and Management Short Answer Questions Set 01

Short Answer Type

Teacher's Note:
1. Give at least four points of difference in an exam.
2. Use a table to make the answer neat.

Question 2. What are traditional methods of irrigation?
Answer:
Traditional methods lift water from wells, lakes and canals by cattle or human labour. They are cheap but less efficient.
(A) Moat (pulley system): a rope passes over a pulley and the bucket is drawn up from the well.
(B) Chain pump: a wheel carrying a chain of buckets lifts the water; it may be run by diesel, biogas, electricity or solar energy.
(C) Dhekli and rahat (lever system): a lever with a weight raises the bucket (dhekli), and a wheel with pots turned by a bullock lifts water (rahat).
In simple words: Traditional methods use human or animal power to lift water from the source.

Teacher's Note:
1. Name three methods and say one line about each.
2. Compare them with sprinkler and drip, which are modern.

Question 3. Why does India need improved agriculture practices?
Answer:
India has a large and growing population that has to be fed, while the land under cultivation cannot be increased much.
Improved practices raise the yield per unit area, protect the soil and natural resources, give farmers a steady income and make the country self-reliant in food.
In simple words: More people must be fed from the same land, so better practices are needed.

Teacher's Note:
1. Use the points of population, yield and self-reliance.
2. Link it with the Green Revolution.

Question 4. Why do we need agriculture?
Answer:
Agriculture gives us food (cereals, pulses, vegetables, fruits, spices), fodder for animals, fibres such as cotton, and raw material for industry.
It also gives employment to about 70% of India's people and contributes a large share of the national income.
In simple words: We need agriculture for food, fodder, fibre and livelihood.

Teacher's Note:
1. Give food, fodder, fibre and employment as the main points.
2. Use the 70% and 40% figures from the chapter.

Question 5. How are biofertilisers ecofriendly?
Answer:
Biofertilisers are living organisms such as Rhizobium, blue-green algae (Anabaena, Nostoc) and phosphate-solubilising micro-organisms.
They are renewable and they enrich the soil with nitrogen and phosphate without causing pollution, unlike chemical fertilisers.
In simple words: They feed the soil with nutrients without polluting it.

Teacher's Note:
1. Contrast them with chemical fertilisers, which cause eutrophication.
2. They are important in organic farming.

Question 6. What is the importance of crops in our daily life?
Answer:
Crops give us food: cereals, pulses, vegetables, fruits, spices and oils.
They also give fodder for cattle, fibres (cotton), beverages (tea, coffee), cocoa, timber and flowers, and so they support farmers' income and many industries.
In simple words: Crops provide food, fodder, fibre and many other everyday things.

Teacher's Note:
1. The answer is written from the chapter's list of sources of food.
2. Mention at least four uses.

Question 7. How does ploughing help in cropping?
Answer:
Ploughing loosens and turns the soil, so it is properly aired.
Roots can then penetrate deep and breathe easily.
It brings nutrient-rich soil upwards, helps earthworms and friendly microbes, and uproots many weeds.
In simple words: Ploughing loosens the soil so roots can grow and breathe.

Teacher's Note:
1. Also mention the crumbs formed, which are broken by levelling.
2. Three points are enough for full marks.

Question 8. How is organic farming useful for the forest (environment)?
Answer:
Organic farming uses little or no chemical fertiliser, pesticide or herbicide, so soil, water and air are not polluted.
Farm waste is recycled as manure, and the soil stays healthy, so less land has to be cleared. Thus it helps protect forests and the environment.
In simple words: Organic farming keeps the environment clean, which protects forests too.

Teacher's Note:
1. Think of pollution prevention and soil health.
2. Think of pollution prevention.

Question 9. Why is sustainable agriculture used?
Answer:
Sustainable agriculture uses farming and management methods that give the best yield while conserving natural resources, keeping the environment in balance and meeting changing human needs.
It secures the livelihood of farmers over the long run through mixed farming, crop rotation, intercropping and integrated farming.
In simple words: It gives good yields without exhausting resources for the future.

Teacher's Note:
1. The answer is written from the chapter's definition.
2. Mention the three goals: conserve resources, keep balance, meet needs.

Question 10. What are the advantages of sustainable agriculture?
Answer:
It is a production and distribution system that fits in natural biological cycles and controls.
It conserves natural resources, maintains the balance of the environment, meets the changing needs of people and assures a lasting livelihood for farmers.
In simple words: It keeps farming productive without harming nature.

Teacher's Note:
1. Link the advantages with the three aims of sustainable agriculture.
2. Link it with the three aims of sustainable agriculture.