Improvement In Food Resources Class 9 Notes | CBSE Science

Key Points for Quick Revision

• Food security depends on both availability and access to food.
• Crop production involves nutrient management, irrigation, and cropping patterns.
• Nutrients are supplied to crops via manure, fertilisers, and biofertilisers.
• Different cropping patterns like mixed cropping, inter-cropping, and crop rotation aim to maximize yield and soil fertility.
• Crop protection management involves controlling weeds, insect pests, and diseases.
• Animal husbandry deals with scientific management of livestock, including breeding, feeding, and disease control.
• Cattle farming provides milk (dairy animals) and draught labour (draught animals).
• Poultry farming focuses on raising domestic fowl for egg and chicken meat.
• Pisciculture (fish farming) can be done in marine or inland water sources.
• Apiculture (bee farming) provides honey and beeswax.

Key Definitions

Hybridisation

The crossing of genetically dissimilar individuals to produce new varieties with desirable characteristics.

Biofortification

Breeding crops with higher levels of vitamins, minerals, or proteins to improve public health.

Organic Farming

A farming system that avoids the use of synthetic fertilisers, pesticides, growth regulators, and livestock feed additives, relying instead on natural methods.

Mixed Cropping

Growing two or more crops simultaneously on the same piece of land, e.g., wheat and gram.

Inter-cropping

Growing two or more crops simultaneously on the same field in a definite pattern, with specified rows for each crop, e.g., maize and soyabean.

Crop Rotation

Growing different crops on the same land in a pre-planned succession to maintain soil fertility and avoid pest/disease build-up.

Vermicomposting

The process of using earthworms to decompose organic waste materials, producing nutrient-rich compost.

Pisciculture

The rearing, breeding, and transplantation of fish by artificial means.

Apiculture

The rearing and management of honey bees for the production of honey and beeswax.

Strategies for Enhancing Crop Production

To meet the growing demand for food, various strategies are employed to improve crop yields and ensure sustainable agriculture. These strategies can be broadly categorized into crop variety improvement, crop production management, and crop protection management.

Crop variety improvement involves developing new crop varieties with desirable traits such as higher yield, improved quality, resistance to biotic (diseases, insects, pests) and abiotic stresses (drought, salinity, heat, cold, frost), shorter maturity duration, and wider adaptability. This is primarily achieved through hybridisation, where genetically dissimilar plants are cross-bred. Another technique is genetic modification, where genes for desired characteristics are introduced into the crop plants. Biofortification is a specific aspect of variety improvement focused on enhancing nutritional content.

Crop production management focuses on optimising the growing conditions for crops. It includes three main aspects:

1. Nutrient Management: Plants require essential nutrients for growth, which are obtained from soil, air, and water. Nutrients are categorized into macronutrients (e.g., Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, Sulphur), required in large quantities, and micronutrients (e.g., Iron, Manganese, Boron, Zinc, Copper, Molybdenum, Chlorine), needed in small amounts. These nutrients are supplied to the soil through manure (organic matter from animal excreta and plant waste, e.g., farmyard manure, compost, vermicompost) and fertilisers (commercially produced plant nutrients like NPK). Manure enriches soil with organic matter, improving water retention and aeration, while fertilisers provide specific nutrients quickly. Biofertilisers use microorganisms to enhance nutrient availability.
2. Irrigation: Supplying water to crops at appropriate intervals is critical for optimal growth, especially in regions with insufficient rainfall. Various irrigation methods are employed, including wells (dug wells, tube wells), canals, river lift systems, and tanks. Modern techniques like drip irrigation and sprinkler systems conserve water and ensure efficient delivery.
3. Cropping Patterns: Strategic arrangement of crops to maximise benefits. Mixed cropping involves growing two or more crops together (e.g., wheat + gram). Inter-cropping involves growing two or more crops simultaneously in definite row patterns (e.g., maize + soyabean). Crop rotation involves growing different crops in sequence on the same land, which helps in pest/disease control and maintains soil fertility, especially when legumes are rotated with non-legumes.

Crop protection management aims to safeguard crops from damage. This involves managing weeds (unwanted plants that compete for nutrients, light, and space), insect pests (which can cut roots, stems, bore into fruits, or suck sap), and diseases (caused by pathogens like bacteria, fungi, viruses). Methods include manual removal of weeds, use of weedicides, biological control, and use of pesticides for pests and diseases. Preventive measures like disease-resistant varieties and proper sanitation are also crucial. Post-harvest storage of grains is also critical to prevent losses from biotic factors (insects, rodents, fungi, bacteria) and abiotic factors (moisture, temperature).

Comparison of Kharif and Rabi Crops

Practical Examples of Food Resource Improvement

• {"title":"Benefits of Crop Rotation","description":"A farmer plants wheat (a cereal) in one season and then switches to gram (a legume) in the next season. The wheat crop utilizes soil nitrogen. When gram is planted, it, being a leguminous plant, replenishes soil nitrogen through nitrogen-fixing bacteria in its root nodules. This practice reduces the need for synthetic nitrogen fertilisers, maintains soil fertility, and can increase the overall yield over time by improving soil health."}
• {"title":"Integrated Farming Systems","description":"In some rural areas, farmers combine crop cultivation with livestock rearing (e.g., cattle or poultry) and pisciculture. The animal excreta can be used to fertilise the crops and fish ponds, providing nutrients. The waste from crops can be used as fodder for livestock. This cyclical system minimizes waste, reduces reliance on external inputs, and provides multiple sources of income (grains, milk, meat, fish), enhancing the overall food resources and farmer's livelihood."}
• {"title":"Improved Poultry Breeds","description":"Through cross-breeding between Indian (e.g., Aseel) and exotic (e.g., Leghorn) poultry breeds, new varieties like Broilers have been developed. These breeds are specifically selected for faster growth rate, higher feed efficiency, lower maintenance costs, and better egg-laying capabilities (in layers). This genetic improvement directly leads to higher production of meat and eggs, improving food availability."}

Exam Tip: Differentiate and Elaborate

In your exams, questions from this chapter often require you to differentiate between similar terms (e.g., mixed cropping vs. inter-cropping, manure vs. fertilisers, Kharif vs. Rabi crops). Practice writing these comparisons in a tabular format, highlighting key distinguishing features. Also, be prepared to elaborate on the advantages and disadvantages of various farming practices or animal husbandry techniques. Use flowcharts or bullet points to present your answers clearly and concisely. Remember to provide relevant examples for better understanding and scoring.

Quick Revision Check

• Q: What are the three main types of crop production management? A: Nutrient management, irrigation, and cropping patterns.
• Q: Name two macronutrients and two micronutrients required by plants. A: Macronutrients: Nitrogen, Phosphorus. Micronutrients: Iron, Zinc.
• Q: Give one advantage of inter-cropping over mixed cropping. A: In inter-cropping, crops are grown in definite patterns, allowing for easier harvesting and spraying of pesticides for individual crops.
• Q: What is the main objective of animal husbandry? A: Scientific management of animal livestock, including breeding, feeding, disease control, and shelter, for food and other useful products.

Frequently Asked Questions