Alfalfa

Alfalfa (Medicago sativa)

The alfalfa (Medicago sativa, also seed alfalfa, alfalfa, alfalfa or clover Perpetual, Eng. Lucerne) is an evergreen, hardy crop from the legume family ( Fabaceae ), subfamily Papilionaceae ( Faboideae ).

Description

The stems can be up to one meter. The plant has a deep root system of more than 4.5 meters in size, which makes them survive unfavorable periods of precipitation ( droughts) well.

Ecology

Alfalfa grows as Hemikryptophyt ( stem plant), sometimes called Chamaephyt. She is an outspoken deep roots. By Journal joints nocturnal sleep movements are possible, whereby the leaflets fold up to protect against night time heat loss upwards.

Like other legumes ( Leguminosae ), the alfalfa the ability with the help of symbiotic root nodule bacteria ( rhizobia ) take nitrogen from the air, and is therefore in a position to form regardless of the amount of nitrogen in the soil protein. The alfalfa lives with her host-specific species Sinorhizobium meliloti in symbiosis.

The flowers are vormännliche " nectar leading butterfly flowers " with quick mechanism. The tension between the boat and Gender column is caused by a spongy tissue on the bottom of the stamen tube. The pollen is already emptied at the opening of the flower and the visitors thrown when sitting on the belly. In a quick process pollinators received a blow, which does not bother many bee species. But avoid the adaptive honeybees after some time the unpleasant shock by reaching the nectar with its proboscis from the side. Result, however, remains of pollination. Therefore, since the 1960s, leaf-cutter bee Megachile rotundata the type are applied to achieve seed set. The flowers are self- sterile because pollen and stigma are separated by a membrane which is ruptured by the fast mechanism. Bloom time is from June to September.

The flowers are almost exclusively visited by bumblebees such as, but experiments in Sweden revealed. There alfalfa fields were dusted in less than 1% of bees, but 78% of bumblebees. In Finland, one has therefore laid cultivation in those areas where still occur very many bumblebees.

The seeds are from the mehrsamigen, spiral, only slightly open shells ejected by the wind. They can then roll as fruit spread further; However, usually there is a random dispersal by ungulates. Fruit ripening takes place in August. Vegetative propagation is possible by branching of the rhizome.

Agriculture

The alfalfa is grown worldwide as a cattle feed, as well as foods ( sprouts ). Very often, if not mostly, it does not concerns with the cultivated plants in Central Europe to the pure type Medicago sativa, but the bastard alfalfa (Medicago x varia).

History

Even in Persia alfalfa was an important food plant for horses. According to tradition, she was sent to about 470 BC in Greece. From there they came to about 150-50 BC to Italy, where it was used as a feed for sheep. At the beginning of the 16th century AD brought the Spanish colonialists, the alfalfa to America, primarily to Mexico and Peru. After Germany they came from Italy by Waldensian around 1700. Sickle Alfalfa is grown in northern areas only been about 200 years.

As alfalfa and meadows ( = red ) clover in the 19th century to Australia and New Zealand were introduced, it was found that no significant seed yield could be achieved because of there not occurring bumblebees. Then in 1885 four bumblebee species were imported to ensure pollination At the suggestion of Charles Darwin.

Up to the present time, alfalfa has claimed in temperate to sub-humid tropical areas.

Cultivation

Their nitrogen-fixing ability improves the efficiency of agricultural soils. When grown on suitable soils that alfalfa is a rich fodder plant. The seeds are sown in the spring on a good remote seedbed with a pH of about 6.8-7.5.

Alfalfa is usually harvested as silage or grass meal pellets, because of high disintegration losses rarer than hay, but can also be used for grazing. They reached the age of five to twelve years, depending on, for example, soil and climate. In Germany it is used 2-3 years, longer in other climates. In most climates alfalfa is cut three or four times a year. The yield is about 10 t dry matter / ha per year, but varies regionally, depending on weather and stage of maturity, when it is cut. The plant should go once a year to flower, to several years to remain usable.

Genetically modified alfalfa

2005 was approved both as a food and as feed in the U.S., the first genetically modified (GM ) alfalfa. Developed by Monsanto 's Roundup Ready alfalfa is resistant to Roundup ( a broad-spectrum herbicide ). In the first year of cultivation in 2006 this alfalfa was grown in the U.S. on an area of ​​approximately 80-100,000 hectares.

2007, the approval in the U.S. was repealed after extensive protests by environmental and consumer protection groups on the orders of a California court again, as the only approval must be preceded by a comprehensive environmental impact assessment. Since then, only under severe restrictions on cultivation was possible. In December 2009, the United States Department of Agriculture (USDA ) with its audit report, which looked at the risk of environmental damage as " unlikely" and recommended to release the cultivation of Roundup Ready alfalfa without any restrictions. On January 27, 2011, the Animal and Plant Health Inspection Service of the USDA announced that Roundup Ready alfalfa is approved after extensive and transparent examinations again without restriction for cultivation.

Additional approvals for cultivation of the product made ​​in Canada and Japan. Field trials were also conducted in Argentina and in 1994 in Belgium and Spain, a commercial use is for the time being, however, not expected in Europe.

Composition

100 g fresh sheet material include:

Other ingredients are coumarin derivatives and saponins. Seeds contain harmful amino acid canavanine, which is degraded during germination most of.