Improvement in Food Resources
NCERT Solutions • Class 9 Science • Chapter 12Chapter Exercises
1. Explain any one method of crop production which ensures high yield.
Inter-cropping
Method: Inter-cropping involves growing two or more crops simultaneously on the same field in a definite pattern (e.g., a few rows of soyabean alternating with a few rows of maize).
How it ensures high yield:
1. Resource Utilization: It ensures maximum utilization of nutrients supplied.
2. Pest Control: It prevents pests and diseases from spreading to all plants of one crop in a field.
3. Risk Reduction: It gives better returns on yield and ensures that if one crop fails, the other survives.
Method: Inter-cropping involves growing two or more crops simultaneously on the same field in a definite pattern (e.g., a few rows of soyabean alternating with a few rows of maize).
How it ensures high yield:
1. Resource Utilization: It ensures maximum utilization of nutrients supplied.
2. Pest Control: It prevents pests and diseases from spreading to all plants of one crop in a field.
3. Risk Reduction: It gives better returns on yield and ensures that if one crop fails, the other survives.
2. Why are manure and fertilizers used in fields?
Manure and fertilizers are used to replenish the nutrients in the soil.
• Continuous farming depletes soil nutrients (like Nitrogen, Phosphorus, Potassium).
• Manure adds organic matter (humus) which improves soil texture and water-holding capacity.
• Fertilizers provide specific inorganic nutrients required for the healthy growth of plants, ensuring good vegetative growth and high yield.
• Continuous farming depletes soil nutrients (like Nitrogen, Phosphorus, Potassium).
• Manure adds organic matter (humus) which improves soil texture and water-holding capacity.
• Fertilizers provide specific inorganic nutrients required for the healthy growth of plants, ensuring good vegetative growth and high yield.
3. What are the advantages of inter-cropping and crop rotation?
| Method | Advantages |
|---|---|
| Inter-cropping | • Prevents spread of pests/diseases. • Max utilization of nutrients. • Risk insurance against crop failure. |
| Crop Rotation | • Replenishes soil nutrients naturally (e.g., using legumes). • Controls weeds and pests. • Allows multiple crops to be grown in a year. |
4. What is genetic manipulation? How is it useful in agricultural practices?
Definition: Genetic manipulation is the process of incorporating desirable characters (genes) into a crop variety by hybridization or by introducing a specific gene, resulting in Genetically Modified Crops (GM crops).
Usefulness:
1. Higher Yield: Increases crop production per acre.
2. Improved Quality: Enhances baking quality, protein content, or oil quality.
3. Resistance: Makes crops resistant to biotic factors (insects, diseases) and abiotic factors (drought, salinity, heat).
4. Maturity Duration: Shortens duration, allowing multiple rounds of crops.
Usefulness:
1. Higher Yield: Increases crop production per acre.
2. Improved Quality: Enhances baking quality, protein content, or oil quality.
3. Resistance: Makes crops resistant to biotic factors (insects, diseases) and abiotic factors (drought, salinity, heat).
4. Maturity Duration: Shortens duration, allowing multiple rounds of crops.
5. How do storage grain losses occur?
Storage losses occur due to two main factors:
1. Biotic Factors Living organisms like insects, rodents, fungi, mites, and bacteria that feed on or degrade the grains.
2. Abiotic Factors Non-living factors like inappropriate moisture content in grains and inappropriate temperature in the storage place.
These factors lead to degradation in quality, loss in weight, poor germinability, and discoloration.
1. Biotic Factors Living organisms like insects, rodents, fungi, mites, and bacteria that feed on or degrade the grains.
2. Abiotic Factors Non-living factors like inappropriate moisture content in grains and inappropriate temperature in the storage place.
These factors lead to degradation in quality, loss in weight, poor germinability, and discoloration.
6. How do good animal husbandry practices benefit farmers?
Good practices (proper feeding, shelter, breeding, disease control) lead to:
1. Increased Production: Higher milk yield (cattle), egg/meat production (poultry).
2. Quality Improvement: Better quality of animal products.
3. Healthier Livestock: Reduced mortality rates and longer productive life.
4. Economic Gain: Improves the overall income and economic status of the farmer.
1. Increased Production: Higher milk yield (cattle), egg/meat production (poultry).
2. Quality Improvement: Better quality of animal products.
3. Healthier Livestock: Reduced mortality rates and longer productive life.
4. Economic Gain: Improves the overall income and economic status of the farmer.
7. What are the benefits of cattle farming?
Cattle farming is done for two main purposes:
1. Milk Production: Milch animals (dairy cows/buffaloes) provide milk which is a major source of nutrition and income.
2. Draught Labour: Draught animals (bullocks) are used for agricultural labor such as tilling, carting, and irrigation.
Additionally, cattle waste (dung) is used as manure and biogas fuel.
1. Milk Production: Milch animals (dairy cows/buffaloes) provide milk which is a major source of nutrition and income.
2. Draught Labour: Draught animals (bullocks) are used for agricultural labor such as tilling, carting, and irrigation.
Additionally, cattle waste (dung) is used as manure and biogas fuel.
8. For increasing production, what is common in poultry, fisheries and bee-keeping?
The common factors for increasing production are:
1. Variety Improvement: Using cross-breeding or selection to obtain improved breeds (high yield, disease resistance).
2. Proper Management: Maintenance of proper temperature, hygiene, and shelter (habitat).
3. Disease Control: Prevention and cure of diseases and pests.
4. Nutrition: Providing scientifically balanced diets/feed.
1. Variety Improvement: Using cross-breeding or selection to obtain improved breeds (high yield, disease resistance).
2. Proper Management: Maintenance of proper temperature, hygiene, and shelter (habitat).
3. Disease Control: Prevention and cure of diseases and pests.
4. Nutrition: Providing scientifically balanced diets/feed.
9. How do you differentiate between capture fishing, mariculture and aquaculture?
| Type | Definition & Source |
|---|---|
| Capture Fishing | Obtaining fish from natural resources (rivers, oceans, lakes). No rearing involved, just catching. |
| Mariculture | Culture (farming) of marine fishes (like mulch, bhetki, pearl spots) and other marine organisms (prawns, oysters) in sea water. |
| Aquaculture | Culturing fish/organisms in both freshwater (rivers, ponds) and marine water. It is a broader term encompassing mariculture. |