All living organisms require food for their growth and survival. The food supplies carbohydrates, proteins, fats, vitamins, and minerals. The two major sources of food are the plants and animals which are obtained from agriculture and animal husbandry. In the present time due to the tremendous increase of human population, the demand for food and shelter are also increased.
Higher grain output can be achieved by bringing more land under cultivation. The other possibility is to increase production efficiency of both plants and animals. Increase in production can be brought about by the development and use of improved varieties with high yield and better managerial practices (both pre and post-harvest).
It is important that food production should be increased without degrading our environment and disturbing natural balance. This is possible through genetic improvement of crop plants (a second green revolution) domesticated animals adopting sustainable agriculture and animal husbandry.
Sources of food:
(i) Cereals: These are rich in carbohydrate and thus provide energy.
e.g. Rice, wheat, maize, sorghum, barley, millets.
(ii) Pulses: These are rich in protein and thus helpful for bodybuilding.
e.g. Gram, moong, pea, lentil, and, pigeon pea.
(iii) Oilseed crops: These are rich in oil and fatty acids.
e.g. Groundnut, sunflower, soya bean, mustard, sesame.
(iv) Vegetable crops: These provide vitamins, minerals along with small quantities of carbohydrate protein and oils.
Leaves: Cabbage, spinach, Trigonella, lettuce
Roots: Carrot, radish, turnip, sweet potato
Stems: Potato, corms, rhizomes (ginger)
Bulbs: Onion, garlic
Fruits: Tomato, brinjal, gourd, cucumber
Flowers: Cauliflower, Bauhinia, banana
(v) Spices: - They are used for enhancing palatability.
e.g. Chilly, black pepper, ginger, turmeric.
(vi) Fodder crops: These provide green fodder to the cattle.
e.g. Berseem, sorghum, maize, oat, sudangrass, alfalfa.