賽芻豆（紫花大翼豆） Macroptilium atropurpureum 20210303164005 01

''Macroptilium atropurpureum'', commonly referred to as purple bush-bean,Macroptilium atropurpureum. (n.d.). Tropical Forages Factsheet. Retrieved from http://www.tropicalforages.info/key/Forages/Media/Html/Macroptilium_atropurpureum.htm or ''siratro'' is a perennial legume recognized by its climbing, dense, green vines and deep purple flowers.Macroptilium atropurpureum. (n.d.). United States Department of Agriculture. Retrieved from http://plants.usda.gov/core/profile?symbol=MAAT80 The plant is indigenous to the tropical and subtropical regions of North, Central, and South America, as far north as Texas in the USA and as far south as Peru and Brazil. It has been introduced for use as a food for stock to many tropical regions around the world. It has become an invasive pest plant in a number of areas, including the north-eastern coast of Australia. Rich in protein, ''M. atropurpureum'' is commonly used for cattle pastures intercropped with grass, used in hay, or as a ground cover to prevent

soil erosion Soil erosion is the denudation or wearing away of the upper layer of soil. It is a form of soil degradation. This natural process is caused by the dynamic activity of erosive agents, that is, water, ice (glaciers), snow, air (wind), plants, a ...

and to improve soil quality.

Description

''M. atropurpureum'' is a tropical herbaceous dicot belonging to the family Fabaceae. It rapidly develops dense, hairy, dark green vines about 5 mm in diameter,Macroptilium atropurpureum Fact Sheet. (2012). The State of Queensland, Department of Agriculture,Fisheries and Forestry. Retrieved from http://www.daff.qld.gov.au/__data/assets/pdf_file/0003/65289/IPA-Siratro-PP93.pdf until it reaches its mature size around 120 cm. The vines have bright green

trifoliolate The following is a list of terms which are used to describe leaf plant morphology, morphology in the description and taxonomy (biology), taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflet (bo ...

leaves, which are roughly 2–7 cm long with smooth hairs on the underside.Macroptilium atropurpureum. (n.d.). Queensland Government Department of Agriculture, Fisheries and Forestry. Retrieved from http://www.daff.qld.gov.au/plants/weeds-pest-animals-ants/weeds/a-z-listing-of-weeds/photo-guide-to-weeds/siratro Flowers are dark reddish purple. The seeds are small brown peas with a white spot, found in the plant's pods which hang on the vines in bunches of about 5-10. In weather and soil conditions favourable to the plant, stem nodes close to the soil may root, enabling vegetative propagation of the plant. ''M. atropurpureum'' forms a deep swollen taproot up to 2 cm in diameter.Heuzé V., Tran G., Hassoun P., Lebas F., 2015. Siratro (Macroptilium atropurpureum). Feedipedia, a programme by INRA, CIRAD, AFZ and FAO. https://www.feedipedia.org/node/278 Last updated on October 7, 2015, 13:51

History and distribution

''M. atropurpureum'' is also commonly referred to as 'Siratro' or 'Aztec' (modified races to improve nematode resistance and reduce rust sensitivity, respectively) ''atro'', purple bush-bean (a common English term for the species), ''Purpurbohne'' (a common German term for the species), or ''conchito'' (a common Spanish name for the species). It has a short lifespan, but a high density, with a minimum of 1200 and a maximum of 1700 plants per acre when it is in season and free to grow. ''M. atropurpureum'' is native to Central and South America, as well as the Caribbean Islands, and has been known to grow in some regions of southern North America, including Mexico and the USA in states such as Arizona, Texas, Florida, and Hawaii, as well as coastal regions in Queensland and New South Wales, Australia, and scattered regions across Africa. Its historical use has been to serve as pasture for domesticated livestock, and was the first tropical pasture improved by breeding. Performed in Australia in 1960s, native ''M. atropurpureum'' was bred to resist nematodes in its roots, which created a modified species known as 'Siratro', which developed a rust sensitivity, so 'Aztec' was developed to counter the arisen problem in 1995. On indigenous North and South American farms where ''M. atropurpureum'' was available, it would often be used as a ground cover during dry seasons to take advantage of the nitrogen-fixation abilities the legume has; this prevented

and acted as an organic fertilizer.A. Angus, A. Lee, M. Lum, M. Shehayeb, R. Hessabi, N. Fujishige, S. Yerrapragada, S. Kano, N. Song, P. Yang, P. Estrada de los Santos, S. de Faria, F. Dakora, G. Weinstock and A. Hirsch (2009). Nitrogen-fixing bacteria communities occurring in soils under different uses in the Western Amazon Region as indicated by nodulation of siratro (Macroptilium atropurpureum). An International Journal on Plant-Soil Relationships, 1, 127-145. The species is invasive in New Caledonia, where it was first introduced in 1963.

Growing conditions

One of the most strategic advantages to ''M. atropurpureum'' is its ability to grow and prosper in varied soil types. It is propagated naturally by legumes bursting and sending seeds forcefully into the ground. Growing season varies geographically, but typically will be in the spring and summer. It can be grown in soils that are coarse and fine, as well as all variations between. Primarily, it is grown on pasture fields interseeded with a grass to retain the soil and prevent erosion. ''M. atropurpureum'' is often found by roadsides, in vegetation around waterways and coastal regions, and on disturbed ground. ''M. atropurpureum'' can grow in soils with a pH level as low as 5.0 and as high as 8.0. It can also survive in most temperatures, requiring a minimum temperature of 23 °F, and has an average salinity and shade tolerance. It requires an average precipitation between 15 and 111 cm. ''M. atropurpureum'' has been tested on several occasions to find additional benefits. When used on a cow pasture intercropped with traditional grass in Australia, it improved milk yield by 2 kg per day. It also improved yields from domestic animals such as goats in Kenya, Zambia, Tanzania, and other African countries. Because of its nitrogen-fixing abilities as a legume, ''M. atropurpureum'' acts as an efficient source of protein for animals when intercropped with grass on the pastures of subsistence and low-income farms, especially in Central and South America. In addition to improving yield, it acts as a ground cover for farmers who need a nutrient-rich ground cover to counter soil erosion and improve soil quality.

Limitations

''M. atropurpureum'' is considered a pest plant under some local government law, including some small local governments in Australia. It has negative effects on native shrubs, grasses, and young trees by smothering them under its dense vines and not allowing them enough sunlight or soil nutrients to grow. 'It' also has a few limitations which include its intolerance to poor water drainage, its declining nutritional value after continued grazing, and its susceptibility to leaf disease. In periods of heavy rainfall, ''M. atropurpureum'' is susceptible to foliar blight (infection from a pathogenic organism).

Nutrients

''M. atropurpureum'' is primarily grown for its high protein content, with protein accounting for about 16% of the plants' dry matter (25% of a ''M. atropurpureum'' vine). Primary amino acids include aspartic acid and proline. It also is a good source of calcium, potassium, and manganese.

Habit

In growth, ''M. atropurpureum'' sprawls outward to cover the ground. By doing so, it acts as an efficient weed suppressor, as it competes with weeds for soil nutrients, and smothers them under its vines. Planting it on a weed-infested field will reduce and kill weed populations, and improve the soil at the same time. It fixes nitrogen from 55 to 175 kg N/ha/year.Macroptilium atropurpureum (DC) Urb. (n.d.). Food and Agricultural Organization of the United Nations. Retrieved from http://www.fao.org/ag/agp/AGPC/doc/gbase/data/pf000049.htm When ''M. atropurpureum'' was used as living mulch in banana plantations, fruit yields improved. Primarily, it should be used for a simple ground covering to control erosion and for revegetation of low-fertility land.

Gallery

File:賽芻豆（紫花大翼豆） Macroptilium atropurpureum 20210303164005 06.jpg File:賽芻豆（紫花大翼豆） Macroptilium atropurpureum 20210303164005 10.jpg File:賽芻豆（紫花大翼豆） Macroptilium atropurpureum 20210303164005 14.jpg File:賽芻豆（紫花大翼豆） Macroptilium atropurpureum 20210303164005 12.jpg File:賽芻豆（紫花大翼豆） Macroptilium atropurpureum 20210303164005 16.jpg File:賽芻豆（紫花大翼豆） Macroptilium atropurpureum 20210303164005 18.jpg