Extra 20 important long questions and answers from the chapter:1 Crop Production and Management for Class 8 Science (CBSE):-
What are the different agricultural practices used for crop production?
The major agricultural practices are:
Preparation of soil
– Loosening and turning the soil.
Sowing
– Placing seeds in the soil for germination.
Adding manure and fertilizers
– Enhancing soil fertility.
Irrigation
– Providing water at regular intervals.
Weeding
– Removing unwanted plants.
Harvesting and storage
– Cutting crops and storing grains properly.
What is ploughing? Explain its importance.
Ploughing is the process of loosening and turning the soil. Importance:
Loosens soil, making it easier for roots to grow.
Improves soil aeration.
Helps in mixing manure and fertilizers.
Removes weeds from the field.
Brings nutrients to the top layer of the soil.
Helps in water retention.
What are kharif and
rabi
crops? Give examples.
Kharif crops:
Sown in the rainy season (June-September). Examples:
Paddy
Maize
Cotton
Groundnut
Jute
Rabi crops:
Sown in winter (October-March). Examples:
Wheat
Barley
Mustard
Gram
Peas
What are the differences between manures and fertilizers?
|
Feature |
Manure |
Fertilizer |
|---|---|---|
|
Source |
Natural (organic) |
Artificial (chemical) |
|
Nutrient content |
Low |
High |
|
Effect |
Improves soil texture |
Increases yield quickly |
|
Examples |
Compost, green manure |
Urea, NPK, superphosphate |
Why is irrigation important for crops?
Irrigation is the artificial supply of water to crops. Importance:
Provides sufficient moisture for growth.
Helps in nutrient absorption by plants.
Prevents crop failure due to drought.
Increases agricultural productivity.
Helps in proper germination of seeds.
Essential for crops grown in dry areas.
Describe the different methods of irrigation.
Traditional methods:
Canal irrigation
– Water is supplied through canals.
Well irrigation
– Water is drawn from wells using pumps.
Basin irrigation
– Fields are flooded with water.
Modern methods:
4.
Drip irrigation
– Water is provided drop by drop to roots.
5.
Sprinkler irrigation
– Water is sprayed like rain over crops.
What is weeding? Why is it necessary?
Weeding is the process of removing unwanted plants (weeds) from fields. Importance:
Weeds compete for nutrients and water.
They reduce crop yield.
They
harbour
pests and diseases.
Weeds block sunlight from reaching crops.
Some weeds release harmful substances.
Weeding ensures better crop growth.
Describe the process of harvesting and its significance.
Harvesting is the process of cutting mature crops from the field.
Ensures timely collection of crops.
Prevents damage by pests and bad weather.
Harvesting can be done manually (using sickles) or mechanically (using harvesters).
Reduces losses due to over-ripening.
Increases efficiency in large-scale farming.
After harvesting, crops undergo threshing and winnowing.
What is crop rotation? What are its advantages?
Crop rotation is growing different crops alternately in the same field.
Maintains soil fertility.
Reduces soil erosion.
Prevents pest and disease
build-up
.
Increases crop yield.
Improves soil texture.
Reduces dependency on chemical fertilizers.
What precautions should be taken while storing grains?
Grains should be stored properly to prevent damage. Precautions:
Drying grains before storage.
Using airtight containers or silos.
Spraying pesticides to kill insects.
Keeping the storage area dry.
Checking regularly for pests.
Using neem leaves or chemicals to prevent infestation.
Explain the advantages of mixed cropping.
Reduces crop failure risk.
Increases total yield.
Improves soil fertility.
Prevents soil depletion.
Reduces pest attacks.
Ensures better utilization of land.
What are the advantages of organic farming?
No harmful chemicals are used.
Improves soil fertility.
Produces healthier crops.
Environmentally friendly.
Reduces pollution.
Conserves biodiversity.
What are the benefits of using bio-fertilizers?
Provides essential nutrients to plants.
Environmentally safe.
Increases soil fertility.
Reduces dependence on chemical fertilizers.
Improves crop yield.
Enhances soil microbial activity.
Describe the effects of excessive fertilizer use.
Soil pollution.
Reduces soil fertility over time.
Contaminates water sources.
Kills beneficial microbes.
Leads to crop damage.
Increases pest problems.
What is the role of earthworms in soil fertility?
Improves soil aeration.
Enhances soil texture.
Converts organic matter into humus.
Helps in decomposition.
Increases soil nutrients.
Maintains moisture balance.
What are silos and granaries?
Used for large-scale grain storage.
Protect grains from pests and moisture.
Made of metal or concrete.
Prevents spoilage.
Used in food industries and by farmers.
Ensures food security.
How does mulching help in agriculture?
Retains soil moisture.
Prevents weed growth.
Improves soil temperature.
Reduces erosion.
Adds nutrients.
Protects plant roots.
How do leguminous plants help in soil fertility?
Fix nitrogen in soil.
Reduce the need for fertilizers.
Improve soil quality.
Increase crop yield.
Prevent soil erosion.
Reduce pest attacks.
19. How do leguminous plants help in soil fertility?
Leguminous plants (e.g., peas, beans, gram) play a crucial role in improving soil fertility.
Role in soil fertility:
Nitrogen fixation
– Leguminous plants have
Rhizobium bacteria
in their root nodules, which convert atmospheric nitrogen into a usable form.
Reduces the need for fertilizers
– Since they fix nitrogen naturally, farmers don’t need to add nitrogen-rich fertilizers.
Improves soil quality
– Adds organic matter to the soil, making it more fertile.
Increases crop yield
– Provides essential nutrients for better plant growth.
Prevents soil erosion
– The roots of leguminous plants help in binding soil particles, reducing erosion.
Reduces pest attacks
– Some leguminous plants naturally repel certain pests, leading to healthier crops.
20. What are the benefits of using modern methods of irrigation?
Modern irrigation methods help in efficient water usage and improve agricultural productivity.
Benefits of modern irrigation:
Water conservation
– Methods like
drip irrigation
and
sprinkler irrigation
save water by providing it directly to plant roots.
Prevents soil erosion
– Unlike flood irrigation, modern techniques prevent excess water from washing away soil.
Increases crop yield
– Proper water supply ensures better plant growth and higher productivity.
Reduces
labor
cost
– Automated systems like sprinklers and drip systems require less manual work.
Minimizes weed growth
– Since water is supplied only to crops, unwanted weeds don’t get sufficient moisture to grow.
Suitable for dry regions
– Areas with low rainfall benefit from controlled irrigation, ensuring year-round farming.
