Short notes and key points of class 9 biology chapter-Improvement in food resources

Short notes and key points of class 9 biology chapter-Improvement in food resources

May 13, 2022, 16:45 IST

Class 9 biology chapter-Improvement in food resources

The two major source of our food are plants and animals.

Types of crops

There are three categories of crops: Food crops, Fodder crops and Commercial crops. The food crops give us carbohydrates, proteins, fats, vitamins and minerals.

On the basis of seasonal variations, the crops of India can be classified as:

• Rabi: It is winter crop grown from November to April. Examples are wheat, gram, peas, etc.

• Kharif: It is a rainy season crop grown from June to October. Paddy, soyabean, maize, cotton, etc.

• Zaid: It is a summer season crop grown from April to June. Cucumbers, melons, etc are zaid crops.

The science of improvement in genotype of plants by improving their genetic potentialities is called plant breeding.

The methods of improving plants by breeding are introduction, selection, hybridisation and genetic engineering (Recombinant DNA Technology).

Manures and Fertilizers

• There are sixteen nutrients, which are essential for plants. Carbon and Oxygen are supplied by air; Hydrogen is supplied by water and remaining 13 elements are supplied by soil.
• Out of 13 essential elements supplied by soil, 6 are required in larger amounts. They are called macronutrients. The remaining 7 are required in minor amounts. They are called micronutrients.
• The major materials which are added into the soil to improve and maintain its fertility are grouped under two categories: 1. Manures and 2. Fertilizers.

Differentiate between manure and fertilizer

NCERT solutions for class 9 Science is prepared by Physics Wallah and consist of solution of all questions asked in NCERT Solutions .

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