HOME
        TheInfoList






A legume (/ˈlɛɡjm, ləˈɡjm/) is a plant in the family Fabaceae (or Leguminosae), or the fruit or seed of such a plant. The seed is also called a pulse. Legumes are grown agriculturally, primarily for human consumption, for livestock forage and silage, and as soil-enhancing green manure. Well-known legumes include alfalfa, clover, beans, peas, chickpeas, lentils, lupins, mesquite, carob, soybeans, peanuts, and tamarind. Legumes produce a botanically unique type of fruit – a simple dry fruit that develops from a simple carpel and usually dehisces (opens along a seam) on two sides.

Legumes are notable in that most of them have symbiotic nitrogen-fixing bacteria in structures called root nodules. For that reason, they play a key role in crop rotation.

Root nodules on a Wisteria plant (a hazelnut pictured for comparison)

Many legumes contain symbiotic bacteria called Rhizobia within root nodules of their root systems (plants belonging to the genus Styphnolobium are one exception to this rule). These bacteria have the special ability of fixing nitrogen from atmospheric, molecular nitrogen (N2) into ammonia (NH3).[17] The chemical reaction is:

N2 + 8H+ + 8e → 2NH3 + H2

Ammonia is then converted to another form,

Some tropical legumes that are closely self-pollinated are: Macroptilium atropurpureum 'Siratro', Macroptilum lathyroides, Centrosema pubescens, Neonotonia wightii, and Lotononis bainesii. However, the autogamous annual Stylosanthes humilis proved otherwise by adapting in response to changing conditions during an experiment, and was found to be composed of several genotypes showing heterogeneity.

Two legumes used for pasture with cross-pollination are: Desmodium intortum and Desmodium uncinatum. When the flower is opened, this is the only time fertilization will take place. These two species' characteristics vary in morphology and ruggedness.[16]

Many legumes contain symbiotic bacteria called Rhizobia within root nodules of their root systems (plants belonging to the genus Styphnolobium are one exception to this rule). These bacteria have the special ability of fixing nitrogen from atmospheric, molecular nitrogen (N2) into ammonia (NH3).[17] The chemical reaction is:

N2 + 8H+ + 8e → 2NH3 + H2

Ammonia is then converted to another form, ammonium (NH+
4
), usable by (some) plants by the following reaction:

NH3 + H+ → NH+
4

This arrangement means that the root nodules are sources of nitrogen for legumes, making them relatively rich in plant proteins. All proteins contain nitrogenous amino acids. Nitrogen is therefore a necessary ingredient in the production of proteins. Hence, legumes are among the best sources of plant protein.

When a legume plant dies in the field, for example following the harvest, all of its remaining nitrogen, incorporated into amino acids inside the remaining plant parts, is released back into the soil. In the soil, the amino acids are converted to nitrate (NO
ammonium (NH+
4
), usable by (some) plants by the following reaction:

NH3 + H+ → NHplant proteins. All proteins contain nitrogenous amino acids. Nitrogen is therefore a necessary ingredient in the production of proteins. Hence, legumes are among the best sources of plant protein.

When a legume plant dies in the field, for example following the harvest, all of its remaining nitrogen, incorporated into amino acids inside the remaining plant parts, is released back into the soil. In the soil, the amino acids are converted to nitrate (NOWhen a legume plant dies in the field, for example following the harvest, all of its remaining nitrogen, incorporated into amino acids inside the remaining plant parts, is released back into the soil. In the soil, the amino acids are converted to nitrate (NO
3
), making the nitrogen available to other plants, thereby serving as fertilizer for future crops.[18][19]

In many traditional and organic farming practices, crop rotation involving legumes is common. By alternating between legumes and non-legumes, sometimes planting non-legumes two times in a row and then a legume, the field usually receives a sufficient amount of nitrogenous compounds to produce a good result, even when the crop is non-leguminous. Legumes are sometimes referred to as "green manure".

Sri Lanka developed the farming practice known as coconut-soybean intercropping. Grain legumes are grown in coconut (Cocos nuficera) groves in two ways: intercropping or as a cash crop. These are grown mainly for their protein, vegetable oil and ability to uphold soil fertility.[20] However, continuous cropping after 3–4 years decrease grain yields significantly.[21]

Distribution and productionSri Lanka developed the farming practice known as coconut-soybean intercropping. Grain legumes are grown in coconut (Cocos nuficera) groves in two ways: intercropping or as a cash crop. These are grown mainly for their protein, vegetable oil and ability to uphold soil fertility.[20] However, continuous cropping after 3–4 years decrease grain yields significantly.[21]

Legumes are widely distributed as the third-largest land plant family in terms of number of species, behind only the Orchidaceae and Asteraceae, with about 751 genera and some 19,000 known species,[22][23] constituting about seven percent of flowering plant species.[24][25]

Storage

Seed viability decreases with longer storage time. Studie

Seed viability decreases with longer storage time. Studies done on vetch, broad beans, and peas show that they last about 5 years in storage. Environmental factors that are important in influencing germination are relative humidity and temperature. Two rules apply to moisture content between 5 and 14 percent: the life of the seed will last longer if the storage temperature is reduced by 5 degree Celsius. Secondly, the storage moisture content will decrease if temperature is reduced by 1 degree Celsius.[26]

Pests and diseases