NCERT Solutions for Class 9 Science Chapter 12 Improvement in Food Resources
NCERT Solutions for Class 9 Science Chapter 12 Improvement in Food Resources covers crop variety improvement, crop production management (nutrients, manure, fertilizers, irrigation, cropping patterns), crop protection management, and animal husbandry (cattle farming, poultry farming, fish production, and apiculture).
Overview of Topics & Subtopics (Click to Jump)
1. Improvement in Crop Yields & Variety Improvement
Short Note:
• Types of Crops:
- Kharif Crops: Grown in the rainy season (June–October), e.g., Paddy, Soyabean, Pigeon pea, Maize, Cotton.
- Rabi Crops: Grown in the winter season (November–April), e.g., Wheat, Gram, Peas, Mustard, Linseed.
• Crop Variety Improvement: Aims to develop high-yielding, disease-resistant crop varieties through hybridisation (crossing between genetically different plants) and genetic modification.
• Objectives: Higher yield, improved quality, biotic and abiotic resistance, wider adaptability, desirable agronomic characteristics.
2. Crop Production Management: Nutrients & Cropping Patterns
Short Note:
• Nutrient Management: Plants require 16 essential nutrients (Air supplies C and O; Water supplies H; Soil supplies 13 nutrients divided into 6 Macronutrients and 7 Micronutrients).
• Manure vs Fertilizers:
- Manure: Organic matter prepared by decomposition of animal waste and plant waste. Enriches soil with humus, improves soil structure, but provides small amounts of nutrients.
- Fertilizers: Commercially produced chemical compounds (rich in N, P, K). High nutrient supply, but excessive use degrades soil fertility and causes water pollution.
• Cropping Patterns:
- Mixed Cropping: Growing two or more crops simultaneously on the same piece of land (e.g., Wheat + Gram).
- Inter-cropping: Growing two or more crops in alternating definite row patterns (e.g., Soyabean + Maize).
- Crop Rotation: Growing different crops on a piece of land in a pre-planned succession to maintain soil fertility.
3. Crop Protection & Storage of Grains
Short Note:
• Weed Control: Weeds are unwanted plants in cultivated fields (e.g., Xanthium, Parthenium, Cyperinus) that compete for nutrients, light, and space. Controlled by herbicides, manual weeding, or proper seed-bed preparation.
• Insect Pests & Diseases: Pests attack crops by cutting roots/stems, sucking cell sap, or boring into fruits/stems. Controlled using pesticides/insecticides, resistant varieties, and biological methods.
• Storage Loss Factors:
- Biotic factors: Insects, rodents, fungi, mites, and bacteria.
- Abiotic factors: Inappropriate moisture and temperature in storage places.
- Prevention: Proper drying before storage, cleaning, and chemical fumigation.
4. Animal Husbandry: Cattle, Poultry, Fish & Apiculture
Short Note:
• Cattle Farming: Undertaken for milk production (milch animals) and agricultural draught labour (draught animals). Cross-breeding indigenous breeds (e.g., Sahiwal, Red Sindhi) with exotic breeds (e.g., Jersey, Brown Swiss) produces high-yield, disease-resistant offspring.
• Poultry Farming: Raised for egg production (layers) and meat production (broilers). Cross-breeding of Indian (e.g., Aseel) and Foreign (e.g., Leghorn) breeds improves chick quality and temperature tolerance.
• Fish Production (Pisciculture & Aquaculture):
- Capture Fishing: Catching fish from natural water sources (marine or freshwater).
- Culture Fishery: Farming fish in controlled water bodies.
- Composite Fish Culture: Combination of 5–6 fish species in a single pond using different feeding zones (e.g., Catlas feed on surface, Rohus in middle zone, Mrigals/Common Carps on bottom).
• Apiculture (Bee-keeping): Practice of keeping honeybees for honey and wax production. Italian bee species (Apis mellifera) is commonly used due to high honey collection capacity, fast breeding, and less stinging nature.
Intext Questions - Page Number: 143
• Cereals (like wheat, rice, maize) provide carbohydrates for energy requirements.
• Pulses (like gram, pea, lentil) provide proteins for body growth and repair.
• Fruits and Vegetables provide a range of vitamins, minerals, along with small amounts of proteins, carbohydrates, and fats.
Intext Questions - Page Number: 145
• Biotic factors: Diseases, insects, pests, and nematodes attack crops, damage plant parts, reduce growth, and lower crop yields.
• Abiotic factors: Drought, salinity, waterlogging, heat, cold, and frost adversely affect germination, plant growth, flowering, and overall crop productivity.
Intext Questions - Page Number: 147
• Manure: Organic and rich in humus. It improves soil texture, aeration, and water-retaining capacity. It restores soil fertility safely over long periods without causing environmental harm.
• Fertilizers: Inorganic chemical salts rich in specific plant nutrients (N, P, K). Continuous and excessive usage damages soil structure, kills soil microbes, lowers long-term soil fertility, and pollutes nearby water bodies.
Textbook Chapter End Exercise Questions
In inter-cropping, two or more crops are grown simultaneously on the same field in a definite row pattern (e.g., 1 row of Soyabean alternating with 1 row of Maize). It prevents pests and diseases from spreading to all plants of a single crop and ensures maximum utilization of applied nutrients and sunlight.
• A combination of five or six different fish species (both indigenous and exotic) are used in a single fish pond.
• Species are selected so that they have different food habits and do not compete for food (e.g., Catlas feed on surface, Rohus in middle zone, Mrigals at the bottom).
• As a result, food available in all parts of the pond is completely utilized, increasing the total fish yield from the pond significantly.
• Proper shelter and clean, well-ventilated housing with adequate temperature control.
• Hygienic food and clean drinking water tailored to nutritional needs.
• Regular vaccination and disease control measures to prevent infections and maintain livestock health.
Read More & Chapter Resources
These short notes are designed for quick revision. Read the main points once, then use the related material below to practise the same chapter. Revising a concept and checking it with questions can make your preparation more focused.