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Legume

life science Maturity 5-7 Next article →

Legumes are a huge group of plants in the pea family, known as Fabaceae.

Various legumes
Various legumes

This family is the third largest of all land plants. It includes about 19,000 different species and 751 genera. Some legumes are grown as food, while others are used for animal feed. When we eat the dry seeds of these plants, we call them pulses.

Pulse in Nanglo
Pulse in Nanglo

This name is used by the Food and Agriculture Organization to describe crops harvested only for their dry seeds. This excludes green vegetables like peas or beans used for oil, such as peanuts.

Legumes have a very special way of helping the earth through nitrogen fixation.

Soil fertility - nitrogen fixation by root nodules on Wistaria roots, with hazelnut to show size
Soil fertility - nitrogen fixation by root nodules on Wistaria roots, with hazelnut to show size

Most legumes have tiny bacteria called Rhizobia living in small bumps on their roots. These bumps are called root nodules. The bacteria take nitrogen from the air and turn it into ammonia. This process provides the plant with the nitrogen it needs to make proteins. When the plant dies, that nitrogen goes back into the soil.

Nitrogen Cycle
Nitrogen Cycle

This acts like a natural fertilizer for the next crops that grow there.

Because they help the soil, farmers use legumes in many smart ways. Many farmers use crop rotation, which means they switch what they plant each season. They might grow a legume one year to add nitrogen to the ground. They can also use legumes as green manure by plowing them back into the soil. In Sri Lanka, farmers use a method called coconut-soybean intercropping. This means they grow soybeans in coconut groves to keep the soil healthy. This helps keep the land strong for many years.

Humans have enjoyed these plants for a very long time.

Early humans and Neanderthals used wild pulses for meals 70,000 to 40,000 years ago. We have found evidence of lentil growing in ancient Egypt and China. The soybean was first grown in China about 5,000 years ago. In the Americas, the oldest beans were found in Guitarrero Cave in Peru. Even Benjamin Franklin helped bring the soybean to the United States in 1770.

Today, we use legumes for much more than just a simple meal. They are a great source of protein, fiber, and minerals like manganese. Some legumes, like lupins, are grown for their beautiful flowers.

Flower garden in Ushuaia (5542996965)
Flower garden in Ushuaia (5542996965)

Other plants in this family are grown for timber or to make dyes and gums. Even animals eat legumes to help them grow better. Whether they are in a garden, a forest, or on a farm, legumes are everywhere.

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🖼️ Images & Media (8)
File:Various legumes.jpg
Various legumes.jpg
File:Soil fertility - nitrogen fixation by root nodules on Wistaria roots, with hazelnut to show size.JPG
Soil fertility - nitrogen fixation by...
File:Nitrogen Cycle.jpg
Nitrogen Cycle.jpg
File:Pulse in Nanglo.jpg
Pulse in Nanglo.jpg
File:Peanut 9417.jpg
Peanut 9417.jpg
File:TrifoliumRepensFlowers.jpg
TrifoliumRepensFlowers.jpg
File:Flower garden in Ushuaia (5542996965).jpg
Flower garden in Ushuaia (5542996965).jpg
File:Pulses for Sale in Market - Darjeeling - West Bengal - India (12431603075).jpg
Pulses for Sale in Market - Darjeeling -...
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