Improvement in Food Resources — NCERT Solutions, AI Tutor & Practice

Understand: Crop improvement means developing crops with better yield, quality and resistance so that food production increases to meet the needs of a growing population.

Major approaches:

1. Crop variety improvement – choosing or breeding varieties with desirable traits like high yield, disease resistance, and better quality.
2. Crop production improvement – using better cultivation practices such as proper nutrient and irrigation management.
3. Crop protection management – protecting crops from weeds, pests and diseases.

Conclude: Improvement is achieved mainly by hybridisation (crossing genetically different plants) and by introducing genes for desired traits (genetically modified crops), combined with good management.

Understand: Agronomic characters are the plant features that make cultivation more productive and convenient.

For cereals: Dwarfness is desirable so that plants stay short, do not lodge (fall over), and use nutrients efficiently for grain production.

For fodder crops: Tallness and profuse branching are desirable because more leafy biomass provides more feed for animals.

Conclude: Breeders select for characters that increase the useful part of the crop — grain in cereals and vegetative growth in fodder.

Understand: Plants need 16 essential nutrients. The difference between macro and micro is the quantity required, not the importance.

Macronutrients (needed in large amounts): Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, Sulphur (6 nutrients).

Micronutrients (needed in small amounts): Iron, Manganese, Boron, Zinc, Copper, Molybdenum, Chlorine (7 nutrients).

Sources:

• Air: Carbon, Oxygen
• Water: Hydrogen, Oxygen
• Soil: the remaining 13 nutrients (macro + micro).

Conclude: Both types are essential; a deficiency of even a micronutrient can reduce plant growth.

Understand: Both supply nutrients, but they differ in composition and effect on soil.

| Feature | Manure | Fertilizer | |---|---|---| | Source | Decomposed plant/animal waste | Industrially manufactured chemicals | | Nutrient content | Low, but adds organic matter (humus) | High, nutrient-specific | | Effect on soil | Improves texture, water holding, microbes | No organic matter added | | Cost/handling | Bulky, cheap | Concentrated, costly |

Conclude: Manure is better for long-term soil health because it restores soil fertility, improves soil structure and water-holding capacity, and increases microbial activity, whereas excessive fertilizer use can destroy soil texture and reduce fertility.

Understand: These are cropping patterns that use land and nutrients efficiently.

Mixed cropping: Growing two or more crops simultaneously on the same field (e.g., wheat + gram). It reduces the risk of total crop failure and gives better use of resources.

Crop rotation: Growing different crops in a fixed sequence on the same field in different seasons. Growing a legume replenishes soil nitrogen through nitrogen-fixing bacteria in root nodules.

Benefits:

• Maintain soil fertility (legumes restore nitrogen).
• Reduce pest and disease build-up.
• Better use of nutrients and moisture.

Conclude: Both practices increase overall productivity while conserving soil health.

Understand: Both involve growing more than one crop, but differ in arrangement and purpose.

Intercropping: Growing two or more crops together in the same field in a definite row pattern (e.g., a few rows of one crop alternate with rows of another). The crops have different nutrient needs, so resources are used more fully.

Difference from mixed cropping:

| Intercropping | Mixed cropping | |---|---| | Definite row pattern | No definite pattern | | Crops harvested and treated separately | Crops mixed together | | Aim: maximize resource use | Aim: minimize risk of failure |

Conclude: Intercropping increases productivity per unit area by using space, light and nutrients efficiently, while reducing pest spread.

Understand: Weeds, insects and pathogens reduce yield, so both prevention and control are needed.

Enemies of crops:

• Weeds – unwanted plants competing for nutrients, e.g., Amaranthus.
• Insect pests – attack roots, stems, leaves; suck cell sap or bore into plants.
• Diseases – caused by bacteria, fungi, viruses.

Control measures:

1. Chemical control – herbicides (weeds), pesticides/insecticides, and fungicides.
2. Preventive/mechanical methods – timely sowing, proper seed bed preparation, intercropping, crop rotation, summer ploughing, and using resistant varieties.

Conclude: Preventive methods reduce the need for chemicals; overuse of pesticides pollutes the environment and harms beneficial organisms, so integrated methods are best.

Understand: After harvest, grains face biotic factors (insects, rodents, fungi, mites, bacteria) and abiotic factors (inappropriate moisture and temperature).

These cause: degradation in quality, loss of weight, poor germination, discolouration, and reduced market value.

Preventive measures:

1. Proper drying of grains to reduce moisture before storage.
2. Cleaning the produce to remove impurities before storing.
3. Fumigation using chemicals that kill pests.
4. Storing in dry, well-ventilated godowns; systematic inspection.

Conclude: Controlling moisture and temperature and preventing pest attack are the keys to reducing storage losses.

Understand: Animal husbandry is the scientific management of livestock, including feeding, breeding and disease control.

Two purposes of cattle rearing:

1. Milk production – milch (dairy) animals, valued by their lactation period.
2. Draught labour – draught animals used for farm work like ploughing and carting.

Practices for good cattle farming:

• Proper shelter – clean, ventilated, sloping floor for drainage.
• Balanced feed – roughage (fibre) + concentrates (nutrient-rich).
• Cross-breeding – e.g., crossing exotic breeds (high yield) with local breeds (disease resistant) for improved milk yield.
• Disease prevention – vaccination, cleanliness, and control of parasites (external and internal).

Conclude: Good husbandry increases both quantity and quality of milk and improves the productive life of the animals.

Understand: Fish production is done both by catching wild fish and by farming fish.

• Capture fishing: Obtaining fish from natural water resources (rivers, seas) without rearing.
• Mariculture: Culture (farming) of marine (sea) fish and other useful sea organisms.
• Aquaculture: Culture of aquatic organisms in fresh, brackish or marine water under controlled conditions.

Composite fish culture: Rearing five or six different species of fish together in a single pond that feed at different water levels (surface, middle, bottom).

• Surface feeders, column feeders and bottom feeders are combined.
• This ensures no competition for food and that all zones of the pond are used, maximising yield.

Conclude: Composite fish culture increases yield because different species use different food resources without competing, giving higher total production from the same pond.

Understand: Apiculture is the rearing of honeybees for honey and wax on a commercial scale.

Value of bee-keeping: Provides honey and wax, and bees help in pollination of crops, improving yield.

Common bee varieties:

• Local: Apis cerana indica (Indian bee), Apis dorsata (rock bee), Apis florae (little bee).
• Introduced Italian bee: Apis mellifera — commonly used for commercial production.

Desirable qualities in a bee variety:

1. High honey collection capacity.
2. Gentle nature — stings less, easy to handle.
3. Ability to stay in the hive for long periods and breed well.

Pasturage: The kinds of flowers available to bees determine the quantity and quality (taste) of honey.

Conclude: Good bee-keeping requires the right bee variety, adequate flowering plants (pasturage), and proper hive management.

Understand: A high-yielding variety carries the potential for higher production, but that potential is only realized under suitable conditions.

Analysis:

• An improved variety needs adequate nutrients (manure/fertilizer), water (irrigation), and protection from weeds, pests and diseases to express its full yield.
• Poor management (nutrient deficiency, drought, pest attack) causes even a good variety to give low yield.
• Similarly, good management with a poor low-yield variety cannot reach high output.

Conclude: Maximum benefit is obtained only when improved varieties are combined with good crop production and protection management — the two must work together to increase total food production.