Legume

Legumes are special plants.

They grow seeds we can eat. We eat beans and peas. Some people call these seeds pulses.

These plants help the soil. They have tiny living things on their roots. These small things take stuff from the air. This helps the plant grow.

When the plant dies, it helps the soil again. This makes the ground good for other plants. Farmers use this to grow food.

Legumes are very good for you. They have lots of protein. They also have fiber.

People have eaten them for a long time. Some even ate them in the Stone Age. Legumes are a great food!

Legumes are a huge family of plants.

This group includes beans, peas, and lentils. Some people call the dry seeds pulses.

Humans eat legumes for protein and fiber. They are also used to make oil.

Legumes do something special for the soil. They have tiny living things on their roots. These are called Rhizobia.

These bacteria take nitrogen from the air. They turn it into a form plants can use. This helps the legume grow strong.

When a legume plant dies, it helps the earth. The nitrogen goes back into the soil. This acts like a natural fertilizer.

Farmers use this to help next crops grow. They often rotate crops to keep soil healthy.

People have eaten these plants for a very long time. Early humans used wild pulses thousands of years ago. Some beans were grown in Peru long ago. Soybeans were first grown in China. Today, we use legumes in many ways. Some grow for food. Others grow for pretty flowers or wood.

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

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.

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.

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.

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.

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.

Legumes are plants belonging to the Fabaceae family, also known as Leguminosae.

This family is the third largest land plant group, following only the Orchidaceae and Asteraceae. It contains approximately 751 genera and 19,000 known species. Legumes are unique because they produce a specific type of fruit. This is a simple dry fruit that develops from a single carpel. Most of these fruits dehisce, which means they open along a seam on two sides. While many people use the term "legume" generally, certain specialized terms exist. When legume seeds are harvested solely for dry grain consumption, they are called pulses.

A defining feature of most legumes is their ability to perform nitrogen fixation. This process relies on a symbiotic relationship with bacteria called Rhizobia. These bacteria live inside small structures on the plant's roots called root nodules.

The Rhizobia take molecular nitrogen (N2) from the atmosphere and convert it into ammonia (NH3). This ammonia is then converted into ammonium, which the plant can use. Because nitrogen is a necessary ingredient for producing proteins, this process makes legumes very rich in nitrogenous amino acids. This biological mechanism allows legumes to thrive even in soils where nitrogen might be limited.

This nitrogen-fixing ability has massive implications for agriculture and the nitrogen cycle.

When a legume plant dies after harvest, its remaining nitrogen is released back into the soil. In the soil, these amino acids are converted into nitrate, which becomes available for future crops. Because of this, farmers often use legumes in crop rotation or polyculture. By alternating legumes with non-legumes, farmers can replenish soil fertility without needing extra nitrogenous fertilizer. Some farmers even use legumes as "green manure." This involves growing the plants and then tilling them directly back into the soil to exploit the captured nitrogen. In Sri Lanka, a specific practice called coconut-soybean intercropping is used in coconut groves to uphold soil fertility.

The variety of legumes available for human use is vast. The Food and Agriculture Organization (FAO) recognizes 11 primary pulses. These include various dry beans like kidney beans, navy beans, and pinto beans. Other important pulses include lentils, chickpeas, and various types of peas. There are also many types of cowpeas, such as the black-eyed pea, and various mung beans. It is important to note that the FAO excludes certain plants from the "pulse" category. This includes green vegetables like green peas, oilseeds like soybeans and peanuts, and forage crops like clover or alfalfa. While these are all legumes, they serve different economic and nutritional purposes.

Legumes are incredibly nutritious for the human diet. They are a significant source of protein, dietary fiber, carbohydrates, and minerals. For example, a 100-gram serving of cooked chickpeas provides 18 percent of the Daily Value (DV) for protein. It also provides 30 percent DV for dietary fiber, 43 percent DV for folate, and 52 percent DV for manganese. Furthermore, legumes are an excellent source of resistant starch. This type of starch is broken down by bacteria in the large intestine to produce short-chain fatty acids, such as butyrate. These fatty acids are used by intestinal cells for energy. Because of this high protein content, legumes are increasingly used as plant-based meat and dairy substitutes.

Humans have been interacting with these plants for tens of thousands of years. Archaeological evidence shows that Neanderthals and early modern humans used wild pulses for meals between 70,000 and 40,000 years ago. Evidence of lentil cultivation has been found in Egyptian pyramids and ancient cuneiform recipes. The soybean was domesticated in China about 5,000 years ago from the wild vine Glycine soja. In the Americas, the oldest domesticated beans were found in Guitarrero Cave in Peru. Even the soybean was introduced to the United States in 1770 by Benjamin Franklin. This long history shows how central legumes have been to human survival and development.

Beyond food, legumes serve many industrial and ecological roles. Some species, like lupins, are grown commercially for their beautiful flowers.

Others, such as Indigofera and Acacia, are used for dye and natural gum production. Some legumes are even used for timber production. However, farmers must protect these crops from various threats. Pests like "bean flies" (Agromyzidae) and black bean aphids can destroy entire crops. Plants also face "biotic" problems like diseases such as rust or root rot, and "abiotic" problems like nutrient deficiencies or pollutants. Managing these factors is essential for maintaining the global supply of these versatile plants.