Pulses are the most important food crops after cereals. They are the quickest means to augment protein production in developing countries. Pulse crops belong to the family Leguminosae and subfamilies Papilionoideae, Caesalpinoideae and Mimosoideae. The roots of many species contain nodules, which are habitat of bacteria capable of fixing atmospheric nitrogen.
The word legume is derived from the Latin word Legumen, means any leguminous plant. An alternative terms for the edible seed of leguminous plant is pulse, derived from the Latin word puls, meaning pottage (thick soup). Split cotyledons of dry legume seed is boiled in water, softened, macerated and used as soup.
Since the grains are used for staple purpose, the word grain legume is often used for leguminous plants. All the pulse crops belong to the family Leguminosae – Papilionoideae. Commonly grown pulse crops in India are given in Table 8.1.
Special Features of Legumes:
Legumes are successful crops and are widely spread from tropics to temperate regions.
They have some special features, which makes them indispensable crops:
1. They are useful both as food and fodder besides as green manure crops.
2. Legumes fix atmosphere nitrogen in their root nodules and improve soils fertility.
3. Nitrogen needs of legumes is low and minimises nitrogen requirement of succeeding crops by around one-fourth of its total requirement.
4. Legumes like Crotolaria and Sesbania can tolerate waterlogged conditions and are useful as green manure crops to rice under such situations.
5. Pulses, as intercrops, in widely spaced crops can suppress the weed growth due to their smothering effect.
6. Legumes like Stylosanthes hamata could serve as cover crops and protect the soil against erosion.
7. Fast growing legume trees like Acacia pendula and Leucaena leucocephala fit well into agroforestry system and aid in reclamation of wasteland.
8. Legumes have higher requirement of P, Ca and greater demand for Mo, B, Cu and Zn.
9. Early maturity, relatively thermo and photosensitivity and better canopy structure of legumes make them the ideal crops in intensive cropping systems.
10. Legume seeds are important sources of protein in vegetarian diet.
11. Among plant sources, pulse proteins are rich in lysine with an average of 70 mg g-1 of protein as compared to 25 mg g-1 in cereals.
Nutritional Importance:
About 15 per cent of dietary protein is met from pulses in India as against 9 per cent in the world (Table 8.2).
Availability of foodstuff in India shows that vegetable products provide highest energy of 2,225 k cal, protein 48 g and fat 33.7 g as compared with cereals and animal products. Among vegetable products, highest protein is in pulses. In India, plant products supply 82 per cent dietary protein as against 18 per cent from animal products.
