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Alfalfa

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Alfalfa, also known by the name lucerne in the United Kingdom and Australia, is a vital perennial flowering plant.

Lucerna - Budaörs
Lucerna - Budaörs

It belongs to the legume family known as Fabaceae. This plant is highly valued worldwide as a major forage crop. Farmers use it for grazing, hay, and silage to feed livestock. It also serves as a green manure or cover crop to help soil. Because it is a perennial, it can live for four to eight years. Some varieties can even live for more than 20 years depending on the climate.

The plant uses a unique biological mechanism to thrive in many environments. Alfalfa forms a tough structure called a crown at the top of its root system. This crown contains shoot buds that allow the plant to regrow after being grazed or harvested. The root system is also incredibly deep and strong. In loose soil, these taproots can extend about 6 feet per year. This depth allows the plant to reach groundwater during droughts. This makes the crop very resilient against soil erosion and dry weather.

A fascinating part of alfalfa's growth is its relationship with bacteria. The plant engages in symbiotic nitrogen fixation with bacteria called rhizobia. Specifically, a type called Sinorhizobium meliloti lives on the plant's roots. These bacteria form small, growing bumps on the root hairs called indeterminate nodules. Inside these nodules, the bacteria transform atmospheric nitrogen into ammonia. This ammonia is a form of nitrogen that the plant can actually use. In exchange, the alfalfa provides the bacteria with carbohydrates for energy. This process improves the nitrogen levels in the surrounding soil.

Alfalfa has a history that spans thousands of years and many continents.

Alfalfa fields in the United States
Alfalfa fields in the United States

It is believed to have originated in south-central Asia. The Roman writer Pliny recorded that it arrived in Greece around 490 BC. In the 4th century AD, the writer Palladius described its use in his book Opus Agriculturae. He noted that one jugerum of alfalfa could feed three horses for a year. In the 16th century, Spanish colonists introduced the plant to the Americas. Later, in the 1850s, alfalfa seeds were imported from Chile to California. This led to the rapid spread of the crop across the western United States.

Today, alfalfa is a massive global industry with significant nutritional value. It is often the highest-yielding forage plant when grown in suitable soils. It is especially important for high-producing dairy cows because of its high protein content. The plant also contains highly digestible fiber. It is used to feed beef cattle, horses, sheep, and goats. Even meat rabbits rely on alfalfa hay for protein. In poultry farming, dehydrated alfalfa is used to color egg yolks and meat. This is because the plant is rich in carotenoids. Humans also consume alfalfa in the form of sprouts, powders, or tea.

Farmers must manage several challenges when cultivating this crop. One issue is autotoxicity, where alfalfa seeds struggle to grow in soil from previous alfalfa stands. To fix this, farmers rotate the crop with plants like corn or wheat. Pests can also cause problems, such as the alfalfa weevil or the spotted alfalfa aphid. The aphid sucks sap and injects toxins into the leaves.

Apis mellifera - Medicago sativa - Valingu
Apis mellifera - Medicago sativa - Valingu

On the bright side, alfalfa is an "insectary plant." It provides a home for predatory insects that can protect other crops like cotton. To keep these helpful insects, farmers might mow in strips rather than the whole field.

Harvesting the crop requires specific steps to ensure quality and storage.

Alfalfa hay, 1915
Alfalfa hay, 1915

Most alfalfa is cut and turned into hay or silage. In many climates, the crop is cut three to four times per year. In very warm areas like Arizona, it can be harvested up to 12 times. A machine called a mower-conditioner can be used to crimp the stems. This helps the plant dry faster after it is cut. Once dry, a tractor pulls a baler to collect the hay.

Alfalfa square bales
Alfalfa square bales

Farmers use small square bales for individual animals or large round bales for cattle ranches.

Alfalfa round bales
Alfalfa round bales

These different sizes make it easier to transport and store this important food source.

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🖼️ Images & Media (9)
File:Apis mellifera - Medicago sativa - Valingu.jpg
Apis mellifera - Medicago sativa - Valingu.jpg
File:Luzerne Kalahari.jpg
Luzerne Kalahari.jpg
File:Alfalfa hay, 1915.jpg
Alfalfa hay, 1915.jpg
File:Alfalfa round bales.jpg
Alfalfa round bales.jpg
File:Alfalfaoutput.png
Alfalfaoutput.png
Alfalfa fields in the United States.webp
File:Lucerna - Budaörs.jpg
Lucerna - Budaörs.jpg
File:Alfalfa square bales.jpg
Alfalfa square bales.jpg
File:Watering alfalfa field.JPG
Watering alfalfa field.JPG
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