Here’s your concise guide to Class 9 Science Chapter 15: Improvement in Food Resources! Ideal for Class 9 students, parents, and teachers prepping for the 2025 CBSE exams, this post covers in-text questions and answers, exercise solutions, and detailed notes on enhancing food production. Let’s explore the Class 9 Science Chapter 15 questions, answers, and notes!
Class 9 Science Chapter 15 Notes
1. Need for Food Improvement
- Goal: Increase yield to feed growing population.
- Challenges: Limited land, water scarcity.
2. Crop Production
- Types: Kharif (monsoon, e.g., rice), Rabi (winter, e.g., wheat).
- Improvement Methods:
- Variety: High-yield, disease-resistant crops.
- Management: Irrigation, fertilizers.
3. Nutrient Management
- Macronutrients: N, P, K (e.g., urea, superphosphate).
- Organic Farming: Manure, compost reduce chemical use.
4. Irrigation
- Methods: Wells, canals, drip irrigation.
- Purpose: Ensure water supply in dry seasons.
5. Crop Protection
- Pests/Weeds: Controlled by pesticides, weedicides.
- Diseases: Managed via resistant varieties, chemicals.
6. Animal Husbandry
- Livestock: Cattle, poultry, fish farming.
- Improvement: Cross-breeding, better feed.
7. Storage
- Loss Prevention: Silos, cold storage stop pest/rot damage.
These notes summarize the chapter—use them for the Q&As!
In-Text Questions and Answers: Page 221
Question 1: Explain in detail how crop variety improvement enhances food production, including the methods used and specific examples of their application.
Answer:
Crop variety improvement enhances food production by developing plants with higher yields, better resistance to diseases and pests, and adaptability to diverse conditions, achieved through selective breeding, hybridization, and genetic modification. Selective breeding chooses plants with desirable traits—e.g., tall wheat with big grains is bred over generations, boosting output. Hybridization crosses different varieties—crossing drought-tolerant maize with high-yield maize creates a hybrid thriving in dry areas like Rajasthan, increasing harvests.
Genetic modification inserts specific genes—Bt cotton, engineered with a bacterial gene, resists bollworms, reducing losses in Maharashtra. Examples: IR8 rice, a high-yield hybrid, doubled India’s rice production during the Green Revolution; Pusa Sawani bhindi resists yellow vein mosaic virus, ensuring steady okra supply. These methods tailor crops to local needs—shorter growth cycles (e.g., wheat maturing in 100 days) allow multiple harvests, while pest resistance cuts pesticide costs. By improving quality and quantity, variety enhancement meets rising food demand sustainably, critical for food security.
Question 2: Discuss comprehensively why irrigation is essential for crop production, including its role in different seasons and examples of irrigation systems in use.
Answer:
Irrigation is essential for crop production because it provides water when rainfall is inadequate, ensuring consistent growth across seasons, especially in rain-dependent regions like India. Rainfall varies—Kharif crops (e.g., rice) rely on monsoons, but erratic rains (e.g., 2023’s dry spells) stunt growth; Rabi crops (e.g., wheat) grow in winter with no natural water, needing irrigation to germinate and yield. It regulates soil moisture, vital for nutrient uptake—dry soil halts photosynthesis, wilting plants.
Examples of systems: Canals in Punjab channel river water to wheat fields, covering vast areas cheaply. Drip irrigation in arid Gujarat delivers water drop-by-drop to grapevines, saving 70% water versus flooding. Wells in Uttar Pradesh tap groundwater for small farms, supporting mustard in dry months. Irrigation doubles yields—irrigated rice produces 5 tons/hectare versus 2 tons rain-fed. It enables year-round farming, stabilizes food supply, and counters drought, making it a backbone of agriculture in diverse climates.
Question 3: Analyze extensively how nutrient management improves crop yield, including the role of fertilizers and organic options, with their benefits and drawbacks.
Answer:
Nutrient management improves crop yield by supplying essential elements plants need for growth—nitrogen (N), phosphorus (P), potassium (K)—via fertilizers and organic sources, each with benefits and drawbacks. Fertilizers like urea (N) boost leaf growth, superphosphate (P) strengthens roots, and potash (K) enhances fruit quality—e.g., NPK application in Punjab wheat fields raises yield from 2 to 4 tons/hectare. They’re fast-acting, precise, and scalable, but overuse leaches chemicals into rivers (e.g., Yamuna pollution), harms soil microbes, and raises costs.
Organic options—manure (cow dung), compost (vegetable waste)—release nutrients slowly, improving soil structure; a farmer in Bihar using compost on maize retains moisture, cutting irrigation needs. Benefits include sustainability and less pollution, but they’re bulky, slower, and less concentrated—10 kg manure equals 1 kg urea. Integrated use—e.g., 50% fertilizer, 50% manure—balances speed and soil health, as in Haryana’s rice paddies. Nutrient management thus optimizes growth, prevents deficiency (e.g., yellowing leaves from low N), and sustains long-term productivity.
In-Text Questions and Answers: Page 228
Question 1: Provide a thorough explanation of how animal husbandry contributes to food resources, including specific practices and their impact on production.
Answer:
Animal husbandry contributes to food resources by rearing animals for milk, meat, eggs, and fish, enhancing supply through breeding, feeding, and health management. Cattle breeding—crossing local cows (e.g., Sahiwal) with high-yield breeds (e.g., Jersey)—increases milk output; a hybrid cow in Punjab yields 20 liters/day versus 5 liters, boosting dairy. Poultry farming uses broiler chickens, fed protein-rich diets, producing 2 kg meat/bird in 6 weeks—e.g., Tamil Nadu farms meet urban demand.
Fish farming (aquaculture) grows carp in ponds, with aeration and feed doubling yield (e.g., 4 tons/hectare in Andhra Pradesh). Health care—vaccinating cattle against foot-and-mouth disease—cuts losses, ensuring steady production. Impact: milk rose 50% in India (1960-2020) via Operation Flood; eggs and fish diversify diets. These practices raise protein availability, improve farmer income, and reduce import reliance, making husbandry vital for food security.
Question 2: Elaborate in detail on why proper storage is critical for food resources, including the causes of loss and methods to prevent it.
Answer:
Proper storage is critical for food resources to prevent losses from pests, moisture, and microbes, ensuring availability post-harvest. Causes of loss: Pests like rats eat 20% of India’s stored grain (e.g., rice in godowns); moisture rots wheat in humid areas, fostering fungi (e.g., aflatoxin in groundnuts); microbes spoil milk without cooling. Methods: Silos store grains dry and pest-free—steel silos in Haryana preserve wheat for years. Cold storage at 4°C keeps fish fresh in Kerala, stopping bacterial growth.
Fumigation with chemicals (e.g., phosphine) kills weevils in pulses. Impact: India loses 10 million tons of food yearly—storage cuts this, saving rice for months (e.g., FCI warehouses). It stabilizes prices—stored mangoes reach off-season markets—and reduces hunger by preserving harvests, making it a linchpin between production and consumption.
Exercise Questions and Answers: Page 239
Question 1: A farmer wants to increase wheat yield. Analyze in detail two methods he could use, including their mechanisms and expected outcomes.
Answer:
Two methods to increase wheat yield:
- High-Yield Variety (HYV): Planting HYV seeds (e.g., HD-2967) bred for more grains per plant. Mechanism: genetic traits enhance photosynthesis and grain size—e.g., Punjab farmers doubled yield (4 tons/hectare) post-Green Revolution. Outcome: More wheat per acre, though it needs fertilizers and water.
- Drip Irrigation: Installing drip systems to deliver water directly to roots. Mechanism: Precise moisture prevents drought stress, boosting growth—e.g., Rajasthan farms raise yield by 30%. Outcome: Higher output with less water waste, ideal for dry regions. Both improve quantity and efficiency sustainably.
Question 2: State two benefits of mixed cropping and explain thoroughly how each benefit supports farmers, with examples.
Answer:
Two benefits of mixed cropping:
- Risk Reduction: Growing maize and beans together—e.g., in Uttar Pradesh—ensures income if maize fails (drought), as beans survive. It spreads risk, stabilizing livelihoods.
- Soil Fertility: Beans fix nitrogen, enriching soil for maize—e.g., a farmer in Bihar cuts fertilizer costs by 20%. This boosts yields naturally, enhancing profit and sustainability. Both support farmers by securing income and resources.
Class 9 Science Chapter 15: Improvement in Food Resources tackles food production for your 2025 CBSE exams. With these notes and Q&As, you’re ready to excel. Check NCERT solutions for more, and comment your questions—we’re here!
For all Class 9 Science Chapters: Notes and Question Answers. Click Here.