Alfalfa (/ælˈfælfə/), also called lucerne and called Medicago sativa is a perennial flowering plant in the legume family Fabaceae. It is cultivated as an important forage crop in many countries around the world. It is used for grazing, hay, and silage, as well as a green manure and cover crop. The name alfalfa is used in North America. The name lucerne is the more commonly used name in the United Kingdom, South Africa, Australia, and New Zealand. The plant superficially resembles clover (a cousin in the same family), especially while young, when trifoliate leaves comprising round leaflets predominate. Later in maturity, leaflets are elongated. It has clusters of small purple flowers followed by fruits spiralled in 2 to 3 turns containing 10–20 seeds. Alfalfa is native to warmer temperate climates. It has been cultivated as livestock fodder since at least the era of the ancient Greeks and Romans. Alfalfa sprouts are a common ingredient in dishes made in South Indian cuisine.
Alfalfa seems to have originated in south-central Asia, and was first cultivated in ancient Iran. According to Pliny (died 79 AD), it was introduced to Greece in about 490 BC when the Persians invaded Greek territory.
Alfalfa is a perennial forage legume which normally lives four to eight years, but can live more than 20 years, depending on variety and climate. The plant grows to a height of up to 1 m (3.3 ft), and has a deep root system, sometimes growing to a depth of more than 15 m (49 ft) to reach groundwater. Typically the root system grows to a depth of 2–3 metres depending on subsoil constraints. Owing to deep root system, it helps to improve soil nitrogen fertility and protect from soil erosion. This depth of root system, and perenniality of crowns that store carbohydrates as an energy reserve, make it very resilient, especially to droughts. Alfalfa is more drought-hardy than drought-tolerant and the persistence of the plant also depends on the management of the stand. It has a tetraploid genome.
Alfalfa is a small-seeded crop, and has a slowly growing seedling, but after several months of establishment, forms a tough “crown” at the top of the root system. This crown contains shoot buds that enable alfalfa to regrow many times after being grazed or harvested; however, overgrazing of the buds will reduce the new leaves on offer to the grazing animal.
Like other legumes, its root nodules contain bacteria, Sinorhizobium meliloti, with the ability to fix nitrogen, producing a high-protein feed regardless of available nitrogen in the soil. Its nitrogen-fixing ability (which increases soil nitrogen) and its use as an animal feed greatly improve agricultural efficiency.[
Alfalfa can be sown in spring or fall, and does best on well-drained soils with a neutral pH of 6.8–7.5. Alfalfa requires sustained levels of potassium and phosphorus to grow well. It is moderately sensitive to salt levels in both the soil and irrigation water, although it continues to be grown in the arid southwestern United States, where salinity is an emerging issue. Soils low in fertility should be fertilized with manure or a chemical fertilizer, but correction of pH is particularly important.
Pests and diseases
Like most plants, alfalfa can be attacked by various pests and pathogens. Diseases often have subtle symptoms which are easily misdiagnosed and can affect leaves, roots, and stems. Some pests, such as the alfalfa weevil, aphids, armyworms, and the potato leafhopper, can reduce alfalfa yields dramatically, particularly with the second cutting when weather is warmest. Spotted alfalfa aphid, broadly spread in Australia, not only sucks sap but also injects salivary toxins into the leaves.
Alfalfa is rich in chlorophyll, carotene, protein, calcium and other minerals, vitamins in the B group, vitamin C, vitamin D, vitamin E, and vitamin K. The sun-dried hay of alfalfa has been found to be a source of vitamin D, containing 48 ng/g (1920 IU/kg) vitamin D2 and 0.63 ng/g (25 IU/kg) vitamin D3. There is reference to vitamin D2 and vitamin D3 being found in the alfalfa shoot; this is awaiting verification.
Sprouting alfalfa seeds is the process of germinatingseeds for consumption usually involving just water and a jar. However, the seeds and sprouts must be rinsed regularly to avoid the accumulation of the products of decay organisms along with smells of rot and discoloration. Sprouting alfalfa usually takes three to four days with one tablespoon of seed yielding up to three full cups of sprouts.
The United States National Institutes of Health (US NIH) reports there is “Insufficient evidence to rate effectiveness [of alfalfa] for” the following:
- High cholesterol. Taking alfalfa seeds seems to lower total cholesterol and “bad” low-density lipoprotein (LDL) cholesterol in people with high cholesterol levels.
- Kidney problems.
- Bladder problems.
- Prostate problems.
- Upset stomach.
- Other conditions.
Like all things moderation is the key. Before consuming large quantities spend some time doing the research to make an informed choice.