Short notes and key points of class 9 biology chapter-Improvement in food resources
Share
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
| S.No. | Manure | Fertilizer |
| 1. |
Manure is a natural substance. It is obtained
by the decomposition of animal wastes such as dung (gobar) of cattle and buffaloes and plant residues. |
A fertilizer is a man-made substance.
It is an inorganic salt or an organic compound. |
NCERT solutions for class 9 Science is prepared by Physics Wallah and consist of solution of all questions asked in NCERT Solutions .
Download Free Pdf sheet of Short notes and key points of Biology for class 9 chapter-Improvement in food resources from the link given below.
