Science Notes of Improvement In Food Resources Class 9 PDF - FREE Download
Improvement in Food Resources Class 9 Notes: CBSE Science Chapter 12
FAQs on Improvement in Food Resources Class 9 Notes: CBSE Science Chapter 12
1. What is the core summary of the CBSE Class 9 chapter 'Improvement in Food Resources'?
This chapter summarises the scientific approaches to sustainably increase food production to meet the demands of a growing population. It covers three main areas: improving crop yields through better varieties and farming practices; managing crop protection against pests and diseases; and enhancing livestock and fish production through scientific animal husbandry.
2. What are the key concepts to focus on for a quick revision of this chapter?
For a quick revision of Chapter 12, focus on these key concepts: Crop Variety Improvement (hybridization, GM crops), Crop Production Management (nutrient management, irrigation, cropping patterns like mixed cropping and crop rotation), and Animal Husbandry (cattle farming, poultry farming, fish production, and bee-keeping).
3. How do plants obtain the essential nutrients they need for growth?
Plants acquire essential nutrients from three primary sources: air (supplies carbon and oxygen), water (supplies hydrogen and oxygen), and soil (supplies thirteen other nutrients). These soil nutrients are absorbed by the roots and are categorised into macronutrients, required in larger quantities, and micronutrients, required in smaller amounts.
4. Why are both manure and fertilisers important for soil fertility, and what is their key difference?
Both are crucial for enriching soil but serve different roles. Manure is organic matter that improves soil structure, increases water retention, and slowly adds a wide range of nutrients. Fertilisers are commercially produced chemicals that provide specific, concentrated macronutrients like Nitrogen (N), Phosphorus (P), and Potassium (K) for rapid plant growth. Using both ensures long-term soil health and immediate nutrient availability for crops.
5. What are the main benefits of using mixed cropping in agriculture?
The main advantages of mixed cropping, where two or more crops are grown together on the same land, include:
- A reduced risk of total crop failure, as different crops may respond differently to weather or pests.
- Improved soil fertility, especially when a legume crop is grown with a cereal crop.
- A lower chance of pest infestation as pests specific to one crop may not spread easily throughout the field.
6. How does crop rotation help in improving food resources sustainably?
Crop rotation is a sustainable practice because it helps maintain and improve soil health over time. By alternating crops with different nutrient needs (e.g., a cereal followed by a legume), it prevents the depletion of specific nutrients. Legumes, through their root nodules, naturally replenish the soil with nitrogen. This practice also helps break the life cycles of pests and weeds specific to one type of crop, reducing the reliance on chemical pesticides.
7. How does changing a crop's maturity duration lead to an improvement in food resources?
Shortening the maturity duration of a crop offers significant economic benefits. It reduces the overall cost of cultivation because the crop spends less time in the field, requiring fewer resources like water and fertilisers. This allows farmers to grow multiple rounds of crops in a single year, which increases the total annual harvest from the same piece of land.
8. What are the essential management practices for good production in poultry farming?
For optimal production of eggs (from layers) and meat (from broilers), several management practices are essential:
- Maintaining proper hygiene and sanitation in their housing.
- Ensuring a well-ventilated shelter with the correct temperature.
- Providing a nutrient-rich diet tailored to their specific needs (broiler vs. layer).
- Implementing a regular vaccination schedule to prevent common diseases.
9. What are the primary methods for obtaining fish for consumption?
Fish can be obtained through two main methods:
- Capture Fishing: This involves harvesting fish from natural resources such as oceans, rivers, and lakes.
- Culture Fishing (Aquaculture): This is the controlled farming of fish in managed environments like ponds, tanks, or coastal sea areas (mariculture). This method helps meet the growing demand that natural fish stocks cannot fulfill alone.
10. Why is bee-keeping considered an important agricultural activity beyond just honey production?
While honey is a primary product, bee-keeping, or apiculture, is vital for agriculture because bees are crucial pollinators. The cross-pollination carried out by bees as they collect nectar significantly increases the yield and quality of many agricultural crops, such as fruits and seeds. Additionally, beehives provide other valuable products like beeswax, which has various commercial and medicinal uses.

















