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Improvement in Food Resources – CBSE NCERT Study Resources

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Improvement in Food Resources

Study Materials

9th

9th - Science

Improvement in Food Resources

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Overview of the Chapter

This chapter discusses the various methods and practices used to improve food resources in India. It covers topics such as crop production, animal husbandry, and sustainable agricultural practices to meet the growing demand for food.

Food Resources: The sources of food that include crops, livestock, and fisheries, which are essential for human survival and economic development.

Crop Production Improvement

Improving crop production involves adopting better farming techniques, using high-yield varieties, and ensuring proper nutrient management. Key methods include:

  • Crop Variety Improvement: Developing high-yielding and disease-resistant crop varieties.
  • Crop Production Management: Using fertilizers, irrigation, and pesticides efficiently.
  • Crop Protection Management: Protecting crops from pests, weeds, and diseases.

Hybridization: The process of crossing two genetically different plants to produce a new variety with desirable traits.

Animal Husbandry

Animal husbandry focuses on the breeding and care of livestock for products like milk, meat, and eggs. Important aspects include:

  • Dairy Farming: Management of cattle for milk production.
  • Poultry Farming: Rearing of birds like chickens and ducks for eggs and meat.
  • Fish Farming (Pisciculture): Cultivation of fish in controlled environments.

Animal Husbandry: The branch of agriculture concerned with the care and breeding of livestock.

Sustainable Agriculture

Sustainable agricultural practices aim to maintain soil fertility and reduce environmental impact. Techniques include:

  • Organic Farming: Using natural fertilizers and pesticides.
  • Crop Rotation: Growing different crops in succession to maintain soil health.
  • Mixed Farming: Combining crop production with livestock rearing.

Sustainable Agriculture: Farming practices that meet current food needs without compromising the ability of future generations to meet theirs.

All Question Types with Solutions – CBSE Exam Pattern

Explore a complete set of CBSE-style questions with detailed solutions, categorized by marks and question types. Ideal for exam preparation, revision and practice.

Very Short Answer (1 Mark) – with Solutions (CBSE Pattern)

These are 1-mark questions requiring direct, concise answers. Ideal for quick recall and concept clarity.

Question 1:
What is crop rotation?
Answer:
Growing different crops alternately to maintain soil fertility.
Question 2:
Name one biofertilizer.
Answer:
Rhizobium (found in legume root nodules).
Question 3:
Define hybridization in crops.
Answer:
Crossing two genetically different plants for better yield.
Question 4:
What is compost?
Answer:
Decomposed organic matter used as fertilizer.
Question 5:
Give one example of a kharif crop.
Answer:
Paddy (rice) or maize.
Question 6:
Why is irrigation important?
Answer:
Provides water for crop growth in dry regions.
Question 7:
Name a dairy breed of cattle.
Answer:
Holstein-Friesian (high milk-yielding breed).
Question 8:
What is apiculture?
Answer:
Rearing bees for honey and wax.
Question 9:
Give one poultry disease.
Answer:
Ranikhet disease (viral infection in chickens).
Question 10:
What is green manure?
Answer:
Growing and plowing crops like sunn hemp for soil enrichment.
Question 11:
Name a micronutrient for plants.
Answer:
Zinc (Zn) or iron (Fe).
Question 12:
What is mixed farming?
Answer:
Growing crops and rearing livestock together.
Question 13:
Give one weedicide example.
Answer:
2,4-D (used to control weeds).
Question 14:
Why are pesticides used?
Answer:
To protect crops from pests and diseases.
Question 15:
What is composting?
Answer:

Decomposing organic waste to enrich soil nutrients.

Question 16:
Name a micronutrient required by plants.
Answer:

Zinc.

Question 17:
What is poultry farming?
Answer:

Raising domestic fowls for eggs and meat.

Question 18:
What is irrigation?
Answer:

Supplying water to crops artificially.

Question 19:
Give one example of a rabi crop.
Answer:

Wheat.

Question 20:
Define composting.
Answer:

Decomposing organic waste into nutrient-rich manure.

Question 21:
What is hybridization in crops?
Answer:

Crossing two genetically different plants for better yield.

Question 22:
Name a weedicide.
Answer:

2,4-D.

Question 23:
What is pasturage in beekeeping?
Answer:

Availability of flowers for nectar collection.

Question 24:
Give one rabi crop example.
Answer:

Wheat.

Question 25:
Name one leguminous crop.
Answer:

Peas or beans.

Question 26:
Give one example of biofertilizer.
Answer:

Rhizobium bacteria.

Question 27:
Give one kharif crop example.
Answer:

Rice or maize.

Question 28:
What is vermicomposting?
Answer:

Using worms to decompose waste.

Question 29:
Name one macronutrient required by plants.
Answer:

Nitrogen

Question 30:
Name one dairy breed of cattle.
Answer:

Sahiwal

Very Short Answer (2 Marks) – with Solutions (CBSE Pattern)

These 2-mark questions test key concepts in a brief format. Answers are expected to be accurate and slightly descriptive.

Question 1:
What is crop rotation and why is it beneficial?
Answer:

Crop rotation is the practice of growing different crops in the same field in sequential seasons.
Benefits include:

  • Prevents soil nutrient depletion
  • Reduces pest and disease buildup
  • Improves soil structure and fertility

Question 2:
Name two macronutrients and two micronutrients required by plants.
Answer:

Macronutrients: Nitrogen (N), Phosphorus (P)
Micronutrients: Iron (Fe), Zinc (Zn)

Question 3:
Why is poultry farming important for humans?
Answer:

Poultry farming provides:

  • High-protein food (eggs, meat)
  • Employment opportunities
  • Manure for crops

Question 4:
List two advantages of mixed cropping.
Answer:

Advantages of mixed cropping:

  • Reduces risk of crop failure
  • Improves soil fertility through nitrogen fixation (if legumes are included)

Question 5:
What is apiculture? Name one product obtained from it.
Answer:

Apiculture is the practice of maintaining honeybee colonies for honey production.
Product: Honey, beeswax, or royal jelly.

Question 6:
How does irrigation help in crop production?
Answer:

Irrigation ensures:

  • Uniform water supply
  • Better crop growth and yield
  • Protection against drought

Question 7:
Define hybridization in crop improvement.
Answer:

Hybridization is the crossing of two genetically different plants to produce offspring with desirable traits like higher yield or disease resistance.

Question 8:
Why are leguminous plants used in crop rotation?
Answer:

Leguminous plants host Rhizobium bacteria in their root nodules, which fix atmospheric nitrogen, enriching the soil for subsequent crops.

Question 9:
What is green manure? Give an example.
Answer:

Green manure is fresh plant material plowed into the soil to improve fertility.
Example: Sunn hemp or Dhaincha.

Short Answer (3 Marks) – with Solutions (CBSE Pattern)

These 3-mark questions require brief explanations and help assess understanding and application of concepts.

Question 1:
Explain the importance of crop rotation in improving food resources.
Answer:

Crop rotation is the practice of growing different crops in succession on the same land to maintain soil fertility and reduce pest buildup.

Importance:

  • Prevents depletion of specific nutrients as different crops have varying nutrient requirements.
  • Reduces soil erosion and improves soil structure.
  • Controls pests and diseases by breaking their life cycles.
  • Enhances yield and sustainability of agriculture.
For example, rotating legumes with cereals replenishes nitrogen in the soil naturally.

Question 2:
What are biofertilizers? Give two examples and their benefits.
Answer:

Biofertilizers are natural fertilizers containing living microorganisms that enrich soil fertility.

Examples:

  • Rhizobium: Fixes atmospheric nitrogen in legume roots, reducing the need for chemical fertilizers.
  • Blue-green algae (Cyanobacteria): Adds nitrogen to rice fields and improves soil health.
Benefits: They are eco-friendly, cost-effective, and enhance soil structure without causing pollution.

Question 3:
Describe the role of hybridization in crop improvement.
Answer:

Hybridization is the process of crossing two genetically different plants to produce offspring with desirable traits.

Role:

  • Enhances yield by combining high-yielding varieties.
  • Improves resistance to diseases, pests, and environmental stress.
  • Develops crops with better nutritional quality (e.g., fortified grains).
For example, hybrid maize shows higher productivity and drought tolerance compared to traditional varieties.

Question 4:
How does intercropping help in sustainable agriculture?
Answer:

Intercropping involves growing two or more crops simultaneously on the same field to maximize resource use.

Benefits:

  • Optimizes soil nutrient utilization as crops have complementary nutrient needs.
  • Reduces pest attacks due to crop diversity.
  • Minimizes soil erosion and improves yield stability.
For instance, growing maize with beans ensures nitrogen fixation and better land productivity.

Question 5:
What is poultry farming? List two indigenous and two exotic breeds of poultry.
Answer:

Poultry farming is the rearing of domesticated birds like chickens, ducks, and turkeys for eggs and meat.

Indigenous Breeds:

  • Aseel: Known for high meat quality and disease resistance.
  • Kadaknath: Valued for black meat and adaptability.
Exotic Breeds:
  • Leghorn: High egg-laying capacity.
  • Rhode Island Red: Dual-purpose breed for eggs and meat.

Question 6:
Explain the importance of crop rotation in agriculture.
Answer:

Crop rotation is the practice of growing different crops in the same field in sequential seasons. It helps in:

1. Soil fertility maintenance: Different crops have varying nutrient requirements, preventing depletion of specific nutrients.
2. Pest and disease control: Breaking the life cycle of pests and pathogens that target specific crops.
3. Weed suppression: Alternating crops disrupts weed growth patterns.
4. Improved soil structure: Different root systems enhance soil aeration and organic matter content.

Question 7:
Describe the role of manure in improving soil quality.
Answer:

Manure is organic matter derived from animal waste and plant residues. Its role in soil improvement includes:

1. Nutrient enrichment: Supplies essential nutrients like nitrogen, phosphorus, and potassium.
2. Soil structure enhancement: Improves water retention and aeration due to increased organic content.
3. Microbial activity: Promotes beneficial soil microorganisms that aid in nutrient cycling.
4. Reduces soil erosion: Binds soil particles, preventing loss due to wind or water.

Question 8:
How does intercropping differ from mixed cropping? Provide one advantage of each.
Answer:

Intercropping involves growing two or more crops simultaneously in the same field in a definite pattern, while mixed cropping grows them without a fixed arrangement.

Advantages:
1. Intercropping: Maximizes resource use (e.g., light, nutrients) due to complementary crop growth patterns.
2. Mixed cropping: Reduces risk of crop failure as different crops have varying environmental tolerances.

Question 9:
Why is poultry farming considered a profitable venture? List three reasons.
Answer:

Poultry farming is profitable due to:

1. High demand: Eggs and meat are staple protein sources globally.
2. Low space requirement: Birds can be reared in small areas with controlled environments.
3. Quick returns: Birds grow rapidly and start laying eggs within months.
4. By-product utilization: Feathers and manure can be sold for additional income.

Question 10:
What are hybrid varieties of crops? Mention two advantages.
Answer:

Hybrid varieties are crops developed by cross-breeding two genetically different parent plants to combine desirable traits. Advantages include:

1. Higher yield: Hybrids often produce more than traditional varieties due to heterosis (hybrid vigor).
2. Disease resistance: Inherit resistance from parent plants, reducing pesticide use.
3. Uniform growth: Plants mature at the same time, easing harvest and management.

Long Answer (5 Marks) – with Solutions (CBSE Pattern)

These 5-mark questions are descriptive and require detailed, structured answers with proper explanation and examples.

Question 1:
Explain the importance of crop rotation in improving food resources with examples.
Answer:
Concept Overview

Crop rotation is the practice of growing different crops sequentially on the same land to improve soil fertility.

Process Explanation
  • Prevents soil nutrient depletion (e.g., legumes fix nitrogen).
  • Reduces pest buildup (e.g., rotating wheat with mustard disrupts pest cycles).
Real-world Application

Our textbook shows farmers in Punjab alternating rice with wheat. In practice, rotating potatoes with peas enhances yield sustainably.

Question 2:
Describe how manure and fertilizers differ in their impact on soil health.
Answer:
Concept Overview

Manure is organic matter from decomposed plants/animals, while fertilizers are synthetic chemicals.

Process Explanation
  • Manure improves soil texture and water retention (e.g., cow dung).
  • Fertilizers like urea provide immediate nutrients but may degrade soil over time.
Real-world Application

NCERT mentions compost pits in villages. Farmers in Kerala combine coconut husk manure with minimal fertilizers for balanced growth.

Question 3:
How does mixed farming enhance food security? Provide NCERT and local examples.
Answer:
Concept Overview

Mixed farming integrates crops and livestock to optimize resource use.

Process Explanation
  • Crop waste feeds animals (e.g., straw for cattle).
  • Animal waste enriches soil (e.g., goat manure for vegetable farms).
Real-world Application

Our textbook cites wheat-poultry systems in Haryana. In Tamil Nadu, farmers grow rice alongside fish ponds for dual income.

Question 4:
Explain biological pest control with one NCERT and one field-based example.
Answer:
Concept Overview

Using natural predators or pathogens to manage pests without chemicals.

Process Explanation
  • Ladybugs control aphids in wheat fields (NCERT example).
  • Neem oil disrupts insect life cycles.
Real-world Application

Andhra Pradesh farmers use Trichoderma fungi against cotton bollworms, reducing pesticide use by 40%.

Question 5:
Compare compost and vermicompost in terms of preparation and benefits.
Answer:
Concept Overview

Both recycle organic waste but differ in decomposition agents.

Process Explanation
  • Compost: Aerobic decomposition (e.g., farm waste piles).
  • Vermicompost: Uses earthworms (e.g., textbook’s red wigglers example).
Real-world Application

Kerala schools teach vermicomposting. Urban gardens use kitchen waste compost for terrace farming.

Question 6:
Explain the importance of crop rotation in improving soil fertility and preventing pests. Provide NCERT and real-world examples.
Answer:
Concept Overview

Crop rotation involves growing different crops sequentially on the same land to maintain soil nutrients and break pest cycles.

Process Explanation
  • Legumes like peas fix nitrogen, replenishing soil fertility.
  • Alternating cereals with legumes prevents pest buildup.
Real-world Application

Our textbook shows wheat-mustard rotation in Punjab. Farmers in Bihar use rice-pulse rotation to improve yields.

Question 7:
Describe mixed farming with its advantages. Give one NCERT and one practical example.
Answer:
Concept Overview

Mixed farming combines crop cultivation and livestock rearing for sustainable agriculture.

Process Explanation
  • Crop residues feed animals, while manure fertilizes fields.
  • Reduces risk of crop failure.
Real-world Application

NCERT mentions wheat-dairy farming in Haryana. Villages in Maharashtra grow jowar alongside goat rearing.

Question 8:
How does composting enhance soil quality? Compare vermicompost with farmyard manure.
Answer:
Concept Overview

Composting decomposes organic waste into nutrient-rich humus for plants.

Process Explanation
  • Vermicompost uses earthworms for faster decomposition.
  • Farmyard manure has slower nutrient release but improves soil texture.
Real-world Application

Our textbook shows Delhi's compost pits. Kerala farmers use coconut husk vermicompost for arecanut plantations.

Question 9:
Explain intercropping with two benefits. Use NCERT's soybean-maize example and a regional practice.
Answer:
Concept Overview

Intercropping grows two or more crops simultaneously for efficient space and resource use.

Process Explanation
  • NCERT shows soybean fixes nitrogen for maize.
  • Reduces soil erosion and increases yield per acre.
Real-world Application

In Karnataka, farmers grow finger millet with pigeon peas as drought-resistant pairing.

Question 10:
What are biofertilizers? Describe their role in organic farming with NCERT and local examples.
Answer:
Concept Overview

Biofertilizers contain living microorganisms that enhance plant nutrient availability.

Process Explanation
  • Rhizobium bacteria in legume root nodules fix atmospheric nitrogen.
  • Reduce chemical fertilizer dependency.
Real-world Application

NCERT mentions blue-green algae for rice fields. Tamil Nadu farmers use Azospirillum for sugarcane crops.

Question 11:
Explain the importance of crop rotation in improving food resources. Discuss how it enhances soil fertility and reduces pest infestation with suitable examples.
Answer:

Crop rotation is the practice of growing different crops in succession on the same piece of land to maintain soil fertility and reduce pest buildup. It plays a crucial role in sustainable agriculture by ensuring long-term productivity.

Enhancing Soil Fertility:
Different crops have varying nutrient requirements. For example, leguminous plants like peas or beans fix atmospheric nitrogen into the soil through Rhizobium bacteria in their root nodules. When these are rotated with nitrogen-demanding crops like wheat or maize, the soil naturally replenishes its nitrogen content, reducing the need for chemical fertilizers.

Reducing Pest Infestation:
Pests are often crop-specific. Continuous cultivation of the same crop allows pests to thrive. For instance, rotating potatoes with non-host crops like mustard disrupts the life cycle of potato beetles, reducing their population. This minimizes pesticide use, promoting eco-friendly farming.

Example:
A common rotation cycle in India is:
1. Kharif season: Rice (depletes nitrogen)
2. Rabi season: Wheat (moderate nitrogen use)
3. Next Kharif: Legumes (restore nitrogen)

This method ensures balanced nutrient utilization, prevents soil exhaustion, and supports higher yields over time.

Question 12:
Describe the role of animal husbandry in food production. Explain how cross-breeding improves livestock quality, citing two examples of Indian cattle breeds and their desirable traits.
Answer:

Animal husbandry involves the scientific management of livestock for enhanced food production, including milk, meat, and eggs. It complements crop farming by utilizing agricultural by-products as fodder, ensuring efficient resource use.

Role in Food Production:
1. Dairy farming provides nutrient-rich milk and derivatives like cheese and yogurt.
2. Poultry supplies eggs and meat, which are high-protein sources.
3. Fish farming (aquaculture) meets the demand for seafood sustainably.

Cross-Breeding for Improved Livestock:
Cross-breeding combines desirable traits of two breeds, such as disease resistance or higher yield. For example:

  • Sahiwal (Indian breed): High milk yield and heat tolerance.
  • Holstein-Friesian (Foreign breed): Exceptional milk production but less adaptable to tropical climates.

By cross-breeding Sahiwal with Holstein, we get offspring with:
1. Higher milk production (inherited from Holstein).
2. Better adaptability to Indian conditions (from Sahiwal).

Example 2:
Gir cattle (known for disease resistance) are cross-bred with Jersey (high-fat milk) to create resilient, high-yielding dairy cows. Such practices boost food security and farmer incomes while maintaining genetic diversity.

Question 13:
Explain the importance of crop rotation in improving food resources. Discuss its benefits with suitable examples.
Answer:

Crop rotation is the practice of growing different crops in succession on the same piece of land to maintain soil fertility and reduce pest infestations. It plays a crucial role in sustainable agriculture by ensuring long-term productivity.

Benefits of crop rotation:

  • Soil fertility improvement: Leguminous crops like peas or beans fix atmospheric nitrogen, enriching the soil for subsequent crops.
  • Pest and disease control: Rotating crops disrupts the life cycle of pests, reducing their buildup. For example, rotating wheat with mustard reduces nematode infestations.
  • Weed suppression: Alternating crops with different growth patterns (e.g., maize followed by potato) prevents weed dominance.
  • Efficient nutrient utilization: Different crops have varying nutrient needs, preventing soil depletion. For instance, rice (heavy nitrogen user) can be rotated with pulses (nitrogen fixers).

Example: A common rotation in India is rice-wheat-pulse. Rice grows in the kharif season, wheat in rabi, and pulses replenish nitrogen in the next cycle, ensuring balanced soil health and higher yields.

Question 14:
Explain the role of manure and fertilizers in improving soil fertility for crop production. Discuss their advantages and disadvantages with suitable examples.
Answer:

Manure and fertilizers are essential for replenishing soil nutrients and enhancing crop productivity. Here’s a detailed comparison:

Manure is an organic substance obtained from the decomposition of plant or animal waste. It improves soil structure, water retention, and microbial activity.
Advantages:

  • Enriches soil with organic matter
  • Eco-friendly and sustainable
  • Prevents soil erosion
Disadvantages:
  • Nutrient content is low and variable
  • Bulky and difficult to transport
Example: Farmyard manure (FYM) or compost.

Fertilizers are chemical compounds rich in specific nutrients like nitrogen (N), phosphorus (P), and potassium (K).
Advantages:

  • High nutrient content ensures rapid growth
  • Easy to store and apply
Disadvantages:
  • Overuse degrades soil quality
  • Can cause water pollution
Example: Urea (N-rich) or Superphosphate (P-rich).

For sustainable agriculture, a balanced use of both is recommended to maintain long-term soil fertility.

Question 15:
Explain the importance of crop rotation in sustainable agriculture. How does it improve soil fertility and reduce pest infestations? Provide examples of crop rotation cycles suitable for Indian farming conditions.
Answer:

Crop rotation is a key practice in sustainable agriculture where different crops are grown sequentially on the same land to maintain soil health and productivity. It plays a crucial role in improving soil fertility and reducing pest infestations.

Importance of Crop Rotation:
1. Soil Fertility: Different crops have varying nutrient requirements. Leguminous crops like peas or beans fix atmospheric nitrogen into the soil, replenishing nitrogen levels for subsequent crops.
2. Pest Control: Rotating crops disrupts the life cycle of pests and diseases, reducing their buildup in the soil.
3. Weed Suppression: Alternating crops with different growth patterns helps suppress weeds naturally.

Examples of Crop Rotation Cycles in India:

  • Rice-Wheat-Pulses: Rice depletes soil nitrogen, wheat follows as a moderate consumer, and pulses replenish nitrogen.
  • Maize-Mustard-Moong: Maize is a heavy feeder, mustard improves soil structure, and moong (green gram) fixes nitrogen.

By adopting crop rotation, farmers can achieve higher yields sustainably while reducing dependency on chemical fertilizers and pesticides.

Question 16:
Explain the importance of crop rotation in sustainable agriculture. Discuss how it improves soil fertility and reduces pest infestations with suitable examples.
Answer:

Crop rotation is a systematic practice of growing different crops in succession on the same piece of land to maintain soil fertility and control pests. It plays a crucial role in sustainable agriculture by ensuring long-term productivity.

Importance of Crop Rotation:

  • Improves Soil Fertility: Different crops have varying nutrient requirements. For example, leguminous plants like peas or beans fix atmospheric nitrogen into the soil through Rhizobium bacteria, replenishing nitrogen levels. When followed by nitrogen-demanding crops like wheat, the soil remains fertile.
  • Reduces Pest Infestations: Pests are often crop-specific. Rotating crops disrupts their life cycles. For instance, rotating potatoes with corn prevents the buildup of potato beetle populations.
  • Prevents Soil Erosion: Deep-rooted crops like alfalfa improve soil structure, reducing erosion.

Example: A common rotation is Wheat → Mustard → Peas. Wheat depletes nitrogen, mustard acts as a natural pesticide, and peas restore nitrogen.

By balancing nutrient use and breaking pest cycles, crop rotation ensures sustainable farming without excessive chemical inputs.

Question 17:
Explain the importance of crop rotation in sustainable agriculture. Discuss how it improves soil fertility and reduces pest infestation with suitable examples.
Answer:

Crop rotation is a systematic practice of growing different crops in succession on the same piece of land to maintain soil fertility and control pests. It plays a crucial role in sustainable agriculture by ensuring long-term productivity.

Importance of Crop Rotation:

  • Improves Soil Fertility: Different crops have varying nutrient requirements. For example, leguminous plants like peas or beans fix atmospheric nitrogen into the soil through Rhizobium bacteria, replenishing nitrogen levels. This reduces the need for chemical fertilizers.
  • Reduces Pest Infestation: Pests are often crop-specific. Rotating crops disrupts their life cycles. For instance, rotating wheat with mustard reduces the risk of wheat rust and aphid attacks.
  • Prevents Soil Erosion: Deep-rooted crops like sugarcane improve soil structure, while shallow-rooted crops like spinach prevent nutrient depletion.

Example: A common rotation in India is Rice-Wheat-Pulses. Rice depletes soil nitrogen, wheat uses residual nutrients, and pulses restore nitrogen, creating a balanced cycle.

Value Addition: Crop rotation also reduces dependency on pesticides, promoting organic farming and environmental sustainability.

Question 18:
Explain the importance of crop rotation in sustainable agriculture. How does it contribute to soil fertility and pest control? Provide examples of suitable crop rotation patterns.
Answer:

Crop rotation is a sustainable agricultural practice where different crops are grown in succession on the same piece of land. It plays a crucial role in maintaining soil fertility and managing pest control.

Importance in Soil Fertility:
Different crops have varying nutrient requirements. For example, leguminous crops like peas and beans fix atmospheric nitrogen into the soil through Rhizobium bacteria, enriching it for the next crop. Growing nutrient-exhausting crops like wheat after legumes ensures balanced soil health.

Pest Control:
Rotating crops disrupts the life cycles of pests and diseases. For instance, if the same crop is grown repeatedly, pests specific to that crop thrive. Changing crops reduces their survival. Example: Rotating potatoes with onions prevents nematode buildup.

Examples of Crop Rotation Patterns:

  • Rice → Wheat → Legumes (e.g., Soybean)
  • Maize → Mustard → Peas

This practice also reduces dependency on chemical fertilizers and pesticides, promoting eco-friendly farming.

Question 19:
Describe the role of manure and fertilizers in improving crop yield. Compare their advantages and disadvantages with respect to soil health and environmental impact.
Answer:

Manure and fertilizers are essential for replenishing soil nutrients, but they differ in composition and impact.

Role in Crop Yield:
Manure is organic matter derived from animal waste or compost, enriching soil with humus and improving water retention. Fertilizers are synthetic chemicals providing specific nutrients (N, P, K) for rapid plant growth.

Comparison:

  • Soil Health:
    Manure enhances soil structure and microbial activity, while excessive fertilizers can degrade soil quality over time.
  • Environmental Impact:
    Manure is eco-friendly but may release greenhouse gases. Fertilizers cause water pollution (eutrophication) if overused.

Advantages & Disadvantages:

  • Manure: Slow-release nutrients, sustainable, but bulky and labor-intensive.
  • Fertilizers: Quick results, easy to apply, but may lead to soil salinity and harm beneficial organisms.

Balanced use of both is recommended for optimal crop yield and long-term soil fertility.

Case-based Questions (4 Marks) – with Solutions (CBSE Pattern)

These 4-mark case-based questions assess analytical skills through real-life scenarios. Answers must be based on the case study provided.

Question 1:
A farmer noticed yellowing of leaves in his wheat crop. Soil testing revealed nitrogen deficiency. Explain the scientific reason behind this observation and suggest two remedies.
Answer:
Case Summary

Yellowing (chlorosis) occurs due to lack of nitrogen, vital for chlorophyll.

Scientific Principle
  • Nitrogen is a key component of amino acids and chlorophyll (NCERT Example: Chapter 15).
Solution Approach
  • Apply urea or ammonium sulfate fertilizers.
  • Grow legumes like peas for natural nitrogen fixation.
Question 2:
In a poultry farm, chicks showed stunted growth and weak eggshells. Identify the nutrient deficiency and propose two dietary improvements.
Answer:
Case Summary

Deficiency of calcium and phosphorus affects bone/eggshell formation.

Scientific Principle
  • Calcium strengthens bones; phosphorus aids metabolism (NCERT Example: Table 15.3).
Solution Approach
  • Add bone meal or oyster shells to feed.
  • Include fishmeal for balanced minerals.
Question 3:
A village faces water scarcity for irrigation. Compare drip irrigation and sprinkler systems with one advantage each.
Answer:
Case Summary

Efficient water-use techniques conserve resources.

Scientific Principle
  • Drip irrigation targets roots directly (NCERT Example: Page 206).
  • Sprinklers mimic rain for uniform coverage.
Solution Approach
  • Drip: Saves 50% water (real-world: Israeli farms).
  • Sprinklers: Covers large fields quickly.
Question 4:
Milk yield dropped in a dairy farm despite proper feeding. Tests confirmed mastitis. List two symptoms and preventive measures.
Answer:
Case Summary

Mastitis is a bacterial infection causing milk spoilage.

Scientific Principle
  • Symptoms: Swollen udders, clotted milk (NCERT Example: Page 212).
Solution Approach
  • Regular udder hygiene with antiseptics.
  • Isolate infected cows to prevent spread.
Question 5:
A farmer noticed yellowing of leaves in his wheat crop. Soil testing revealed nitrogen deficiency. Explain the scientific reason and suggest two organic methods to address this issue.
Answer:
Case Summary

Yellowing (chlorosis) indicates nitrogen deficiency, crucial for chlorophyll.

Scientific Principle
  • Nitrogen aids protein synthesis and growth (NCERT Class 9).
Solution Approach
  • Use compost (decayed organic matter) or green manure like sunn hemp (NCERT example).
  • Crop rotation with legumes (real-world) fixes atmospheric nitrogen.
Question 6:
In a poultry farm, chicks showed stunted growth and low egg production. Identify two nutritional causes and preventive measures.
Answer:
Case Summary

Poor growth and egg production suggest protein/calcium deficiency.

Scientific Principle
  • Proteins build tissues (NCERT), calcium strengthens eggshells.
Solution Approach
  • Feed fishmeal (protein-rich) and oyster shells (calcium source).
  • Balanced diet with vitamins (real-world) prevents deficiencies.
Question 7:
A beekeeper observed fewer bees and low honey yield. Link this to forage crops and suggest two improvements.
Answer:
Case Summary

Bee decline relates to scarce nectar/pollen sources.

Scientific Principle
  • Bees need flowering plants (NCERT: apiculture depends on flora).
Solution Approach
  • Plant sunflower or mustard (NCERT examples).
  • Avoid pesticides (real-world) to protect bees.
Question 8:
An experiment compared irrigation methods (drip vs. flood) for tomato yield. Tabulate results and conclude.
Answer:
Case Summary

Drip irrigation saves water and improves yield.

Scientific Principle
MethodWater Used (liters)Yield (kg)
Drip500120
Flood80090
Solution Approach

Drip is efficient (NCERT) and suits water-scarce areas (real-world).

Question 9:
A farmer noticed yellowing of leaves in his wheat crop. Soil testing revealed nitrogen deficiency. Explain the scientific reason behind this symptom and suggest two organic solutions.
Answer:
Case Summary
Yellowing (chlorosis) occurs due to nitrogen deficiency, as nitrogen is vital for chlorophyll.
Scientific Principle
Our textbook shows nitrogen is a key component of amino acids and chlorophyll (NCERT Example: Legume-Rhizobium symbiosis).
Solution Approach
  • Apply compost or farmyard manure to enrich soil nitrogen.
  • Grow green manure crops like sunn hemp (Real-world example: Indian farmers use it post-harvest).
Question 10:
In a poultry farm, chicks showed stunted growth and feather loss. The feed lacked protein and vitamins. Identify the nutrient deficiency and propose two feed additives.
Answer:
Case Summary
Stunted growth and feather loss indicate protein-energy malnutrition.
Scientific Principle
We studied that poultry requires 20-22% protein (NCERT Example: Fishmeal in poultry feed).
Solution Approach
  • Add soybean meal (rich in proteins).
  • Include vitamin premixes (Real-world: Commercially available as 'Growvit').
Question 11:
A beekeeper observed low honey yield due to fewer foraging bees. Analyze the ecological factor causing this and suggest two practices to improve yield.
Answer:
Case Summary
Fewer bees indicate poor floral resource availability.
Scientific Principle
Our textbook shows bees need nectar/pollen from flowers (NCERT Example: Apple orchards benefit from beekeeping).
Solution Approach
  • Plant bee-friendly crops like sunflower nearby.
  • Ensure continuous blooming by seasonal planting (Real-world: Himachal Pradesh farmers use mixed cropping).
Question 12:
An experiment compared crop yields using chemical fertilizers (Plot A) and vermicompost (Plot B). Results:
PlotYield (kg/ha)Soil pH
A32005.8
B28006.9
Interpret the data and justify long-term sustainability of Plot B.
Answer:
Case Summary
Plot B has lower yield but better soil pH.
Scientific Principle
We studied that vermicompost improves soil structure (NCERT Example: Organic farming in Sikkim).
Solution Approach

Though yield is less, Plot B maintains neutral pH (6.9) vs acidic (5.8), preventing soil degradation. Real-world: Punjab farmers adopt organic methods to reduce chemical overuse.

Question 13:

Rahul, a farmer, noticed that his wheat crop was not growing well despite using chemical fertilizers. His friend suggested using organic manure instead. Based on this case:

  • Explain why organic manure is better than chemical fertilizers for soil health.
  • List two advantages of using organic manure.
Answer:

Organic manure is better than chemical fertilizers because it improves soil structure, enhances water retention, and promotes microbial activity. Unlike chemical fertilizers, it does not cause soil degradation or pollution.

  • Advantages of organic manure:
    1. It enriches the soil with humus, improving fertility over time.
    2. It is eco-friendly and reduces dependency on synthetic chemicals.
Question 14:

In a village, farmers were advised to adopt crop rotation instead of growing the same crop repeatedly. Analyze this situation and answer:

  • How does crop rotation help in maintaining soil fertility?
  • Name one leguminous crop that can be used in rotation and explain its role.
Answer:

Crop rotation maintains soil fertility by preventing nutrient depletion and reducing pest buildup. Different crops have varying nutrient needs, so rotation ensures balanced soil health.

  • Example of leguminous crop: Peas.
    Peas have nitrogen-fixing bacteria in their root nodules, which enrich the soil with nitrogen, reducing the need for fertilizers.
Question 15:
A farmer in Punjab grows wheat in his field. He notices that the yield is decreasing every year despite using chemical fertilizers. Based on this case, answer the following:
(a) What could be the possible reason for the decreasing yield?
(b) Suggest two sustainable practices the farmer can adopt to improve soil health and crop yield.
Answer:

(a) The decreasing yield despite using chemical fertilizers could be due to soil degradation. Overuse of chemical fertilizers can lead to:
- Loss of soil fertility as they kill beneficial microorganisms.
- Soil acidification or alkalization, disrupting nutrient availability.
- Reduced water retention capacity of the soil.

(b) Two sustainable practices the farmer can adopt are:
1. Crop rotation: Growing legumes (like peas or beans) alternately with wheat to naturally replenish nitrogen in the soil.
2. Organic farming: Using compost or manure instead of chemical fertilizers to improve soil structure and microbial activity.

Question 16:
In a village, farmers rely on rainwater for irrigation, leading to crop failures during droughts. The government introduces a drip irrigation system. Analyze the case and answer:
(a) How does drip irrigation conserve water compared to traditional methods?
(b) List two additional benefits of drip irrigation for crop production.
Answer:

(a) Drip irrigation conserves water by:
- Directly supplying water to the root zone of plants, minimizing evaporation.
- Reducing water wastage through runoff or percolation, unlike flood irrigation.

(b) Two additional benefits are:
1. Precision nutrient delivery: Fertilizers can be mixed with water (fertigation), ensuring efficient uptake by plants.
2. Weed control: Since water is targeted, weed growth in non-crop areas is minimized.

Question 17:
A farmer in Punjab grows wheat and rice alternately in the same field. He notices that over time, the yield of both crops has decreased. Based on this case, answer the following:

1. What agricultural practice is the farmer following?
2. Suggest two measures to improve the yield with scientific reasoning.
Answer:

1. The farmer is practicing crop rotation, where different crops are grown alternately in the same field to maintain soil fertility.

2. Two measures to improve yield are:

  • Use of organic manure or compost: Adding organic matter replenishes soil nutrients like nitrogen and phosphorus, improving soil structure and fertility.
  • Intercropping with legumes: Growing legumes like peas or beans alongside wheat/rice fixes atmospheric nitrogen through Rhizobium bacteria, naturally enriching the soil.

These methods reduce dependency on chemical fertilizers and enhance long-term productivity.

Question 18:
A dairy farmer observes that his cows are producing less milk despite adequate feeding. Analyze the case and answer:

1. Identify two possible reasons for reduced milk production.
2. Suggest two scientific solutions to address this issue.
Answer:

1. Possible reasons for reduced milk production:

  • Poor breed quality: Low-yielding or non-native breeds may produce less milk.
  • Inadequate nutrition: Lack of balanced feed with proteins, minerals, and vitamins affects milk yield.

2. Scientific solutions:

  • Cross-breeding with high-yielding varieties: Introducing breeds like Jersey or Holstein-Friesian improves genetic potential for milk production.
  • Providing balanced ration: Feed should include green fodder (e.g., berseem), concentrates, and mineral supplements to meet nutritional requirements.

Proper shelter hygiene and regular veterinary care also boost productivity.

Question 19:
A farmer in Punjab is growing wheat in his field. He notices that the yield is lower than expected despite using chemical fertilizers. Based on this scenario, answer the following:

1. Suggest two possible reasons for the low yield.
2. What alternative practices can the farmer adopt to improve soil health and crop yield?
Answer:

1. Possible reasons for low yield:
Soil degradation due to excessive use of chemical fertilizers, which reduces microbial activity.
Waterlogging or poor irrigation practices leading to root damage.

2. Alternative practices:

  • Use of organic manure or compost to restore soil fertility.
  • Practice crop rotation with legumes to naturally replenish nitrogen.
  • Adopt drip irrigation to conserve water and prevent waterlogging.

These methods enhance sustainable agriculture while maintaining long-term soil health.

Question 20:
In a village, farmers are struggling with pest attacks on their crops. They rely heavily on chemical pesticides, but the pests seem to be developing resistance. Analyze the situation and answer:

1. Why are pests becoming resistant to chemical pesticides?
2. Suggest two eco-friendly pest control methods with explanations.
Answer:

1. Reason for pest resistance:
Overuse of chemical pesticides leads to natural selection, where only resistant pests survive and reproduce, passing on their resistance traits.

2. Eco-friendly pest control methods:

  • Biological control: Introduce natural predators like ladybugs to control aphids.
  • Neem-based pesticides: These disrupt the life cycle of pests without harming beneficial insects.

These methods reduce environmental pollution and promote balanced ecosystems in agriculture.

Question 21:
A farmer in Punjab observed that his wheat crop was not yielding as expected despite using fertilizers. Upon soil testing, it was found that the soil lacked nitrogen and phosphorus. Suggest two sustainable practices he can adopt to improve soil fertility and explain how they work.
Answer:

The farmer can adopt the following sustainable practices to improve soil fertility:

  • Crop Rotation: Growing leguminous crops like peas or beans in rotation with wheat. Rhizobium bacteria in their root nodules fix atmospheric nitrogen, enriching the soil naturally.
  • Organic Manures: Applying compost or farmyard manure. These decompose to release nitrogen and phosphorus slowly, improving soil structure and water retention.

Both methods reduce chemical fertilizer dependency and enhance long-term soil health.

Question 22:
In a village, farmers rely on rainwater for irrigation, leading to crop failures during droughts. Design a water management plan using two scientific methods to conserve water and ensure crop sustainability.
Answer:

The following water management plan can be implemented:

  • Drip Irrigation: A system where water drips slowly to plant roots through pipes.
    It minimizes evaporation and ensures efficient water use.
  • Rainwater Harvesting: Collecting rainwater in ponds or tanks during monsoons.
    Stored water can be used during dry spells for irrigation.

These methods reduce water wastage, improve availability, and support crop growth even in water-scarce conditions.

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