Improvement in Food Resources - Revision Notes

 CBSE Class 9 Science

Revision Notes
Improvement in food resources

1. Food Resources: Cereals (Wheat, rice, maize, millets and sorghum) provide us carbohydrates; Pulses (Grams, pea and lentil) provide us proteins; Oil seeds (Soya bean, ground nut, sesame, and castor) provide us fats; Vegetables, spices and fruits provide us a range of minerals, nucleic acids and vitamins.

In addition to these food crops, fodder crops like berseem, oats or sudan grass are raised as food for the livestock are called as fodder crops.

2. The Kharif crops: The crops grown in rainy season are called as Kharif crops (Paddy, Soya bean, pigeon pea and maize). They are grown from June to October.

3. The Rabi crops: The crops grown in winter season are called Rabi crops (Wheat, gram, peas, and mustard). They are grown November to April.

Compare Kharif crops and Rabi crops:






Kharif crops

June to October ( Rainy Season)

Paddy, Soya bean, and maize


Rabi crops

Nov. to April ( winter season)

Wheat, gram, peas, and mustard

4. The Green Revolution: Food supplies are generally as proteins, carbohydrates, fats, minerals, nucleic acids and vitamins in all living organisms. Indian population is growing enormously. Green Revolution is the need of the hour to increase food-grain production.

5. Sustainable Practices: For sustained livelihood, one should undertake mixed farming, inter cropping, and integrated farming practices, for example, combining agriculture with livestock/ poultry/ fisheries/bee-keeping. The major group of activities for improving crop yield can be classified as: Crop varietal improvement, Crop production improvement, Crop protection improvement

6. The Crop varietal improvement:

a) Hybridization: It refers to crossing between genetically dissimilar plants;It is all to get higher yield, improved quality, biotic and abiotic resistance, change in maturity duration, wider adaptability and desirable agronomic characteristics.





Inter varietal Hybridization

between different varieties


Inter specific Hybridization

between different species


Inter generic Hybridization

between different genera


Genetically Modified Crops (GMC).

Another way of improving the crop is by introducing a gene that would provide desired characteristic.

7. The Crop production improvement: They include” no cost production”,” low cost production” or “high cost production” practices.

  1. Nutrients (Sixteen elements are required for growth are called as essential elements Carbon, oxygen, hydrogen+ Macro nutrients & Micronutrients. They increase the yield)


Macro nutrient

Micro nutrient


Six elements are required in larger quantity

Other seven elements are required in small quantity


Ex.Nitrogen, phosphorus, calcium, Potassium, magnesium, sulphur

Ex. Iron, manganese, boron, zink, copper, molybdinum, chlorine

  1. Manure & Fertilizers:





Manure is prepared by the decomposition of animal excreta and plant waste is called as Humus. It decides the texture of the soil.
Compost: Farm waste, cow dung etc.
Vermi compost: Compost prepared by using earthworms.

Fertilizers are commercially produced plant nutrients. Excess fertilizers destroy the soil fertility.
Organic farming: No use of chemicals fertilizers, herbicides, pesticides etc.
Culturing blue green algae, neem leaves, healthy cropping systems.


It is cheap and prepared in rural homes and fields

It is costly and is prepared in factories


It is voluminous and bulky

It is compact and concentrated



It is inconvenient to store, transport, handle.

It is easy to store, transport, handle.


It is not nutrient specific.

It is nutrient specific and can provide specifically nitrogen, phosphorus etc.


Add great humus to the soil

Does not add humus to the soil.

3. Irrigation: India has variety of water resources: Wells, canals, river lift system, tanks, rainwater harvesting, water shedding management to increase in ground water levels and to check the water flowing away to the sea. Planning to reduce soil erosion.

4. Cropping patterns:

S N.

Mixed cropping


Crop rotation


Two or more crops Grown simultaneously on the same piece of land

Two or more crops grown simultaneously on the same piece >of land in a definite pattern

Growing different crops on a piece of land in a pre-planned succession


Ex. Wheat+ Gram Wheat+ Mustard; Wheat+ gram; Groundnut+sunflower.

Soyabean + maize/bajra + Cowpea

Two or three crops can be grown in a year depending upon the duration.


A type of insurance against failure of one of the crops.

A few rows of one crop alternate with a few rows of a second crop. Crops are selected such that their nutrient requirements are different. This ensures the maximum utilization of the nutrients supplied and prevents pests and diseases spreading in the crop field

The availability of moisture and Irrigation facilities decides the choice of the crop to be cultivated.

8. Crop protection improvement/ management: Field crops are infested by large number of weeds, insects pests, diseases & storage of grains



Insect pests


Storage of grains


Weeds are unwanted plants in the crop field

Insect pest is nuisance in the crop field

Disease is caused by pathogens in the field

Different factors are responsible.


Weeds take up nutrients and reduce the growth

Insect pest affect the health of crop and reduce the yield.

Diseases alter the physiology of crops and reduce the yield

Different factors reduce the quality of stored grains


Ex. Xanthium, Parthenium

Ex. Caterpillars, dragonfly

Ex. Bacteria, Virus

Botic factors: insects, rodents, fungi Abiotic factors: moisture & temperature


Removal of weeds at an early stage is recommended.

Spray weedicides

Spread of chemicals such as pesticides

Spread of chemicals to kill pathogens

Systematic management of ware house.

9. Animal Husbandry: It is a scientific management of animal livestock, includes feeding, breeding and diseases control. Animal-based farming includes cattle farming, Poultry farming, fish farming, and bee Keeping.



Cattle farming

Poultry farming

Fish farming

Bee Keeping.



Milk (milch animals) and draught labor (draught animals) in agriculture.

Meat, chicken, egg production

Cheep source of animal protein. Fish production is aquaculture. Growing of marine fishes is Called mari culture.

Honey, wax, Medicinal preparations.

Additional income to the farmer.


Cross breeding:
To get desired qualities

Exotic- quality of lactation Indigenous breeds- quality of disease resistance

Exotic &
Indigenous breeds

Both Exotic & Indigenous fishe sare used

Exotic- high honey collection capacity & stingless.
Indigenous bees-are used


Desirable maintenance

Good ventilation in sheds Roughage/ concentrates Protection from parasites &skin diseases Vaccination

Good ventilation in sheds Roughage/ concentrates Protection from parasites & skin diseases Vaccination

Fish farming/locating large schools of fish/use of satellites and echo-sounds
In Composite fish culture seed is wild, mixed with other species. Hormonal stimulation to bring desired quality in fish production.

Value or quality depends upon the pasturage or the flowers available for the taste of honey.



Exotic or foreign breeds (Jercy, brown Swiss)Local breeds (Red sindhi, Sahiwal)

Exotic-Leghorn Indigenous breeds- Aseel

Fresh water (Macrobrachium)& Marine(Peneaus) prawns Fresh water fishes Marine fishes(Bombay duck, sardines) Common

Apisceranaindica Dorsata A. florae