Astragalus adsurgens Pallas
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Astragalus adsurgens Pallas
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Leguminoseae Synonyms
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Author: J.M. Suttie |
Common names North China Milkvetch, Standing Milkvetch Status North China milkvetch is a perennial which occurs naturally in Northern China, Japan, Korea and Mongolia and in N. America in Alaska, the Aleutian Islands, and the northern parts of the USA and Canada. It has recently been domesticated in Central China as a fodder and is usually cut for hay or silage. North China milkvetch it is a tall, deep-rooted, scandent, herbaceous and strongly perennial which may reach 1.5 metres in height. Its leaves are pinnate and flowers usually blue to bluish purple. It can be grown on poor soils and withstands drought and cold well; it is less well liked as a fodder than lucerne but is hardier on some poor sites; seed production was a problem since in the more northerly areas late-flowering ecotypes were cut back by frost before seed-set but researchers have now produced earlier-flowering varieties. It has been widely used in pasture renovation, watershed management and fodder development in the Loess Plateau area. Environmental adaptation North China milkvetch withstands very cold winters but requires a hot growing season. It prefers well-drained soils of high pH and survives on low rainfall, from 300 mm per year, but uses a great deal of the available moisture. The common Chinese cultivars have been developed in central to northern areas and are very late flowering; their range in cold, northerly areas is limited by difficulties of seed production; they flower too late and are cut by frost. The crop may, of course, be grown for fodder in areas with too short a growing season for good seed-set. Cultivation and management Seed rate and establishment: it is usually line sown at about 5 kg/ha of scarified seed at the onset of the rains, but may be broadcast. It is not usually harvested in the first year in semi-arid areas. Maintenance and management: mowing and perhaps weeding is all the crop usually receives once established, but top dressing with phosphatic fertiliser would improve its longevity and production. Seed production: is by cutting the whole plant once the seeds are fully formed, drying and threshing; seed growing areas must fit the flowering pattern of the cultivar. Crop use and grazing management Its palatability is only moderate and it is better accepted as silage or hay than in the fresh state. Maintenance and management: mowing and perhaps weeding is all the crop usually receives once established, but top dressing with phosphatic fertiliser would improve its longevity and production. Conservation Hay: in northeast China Astragalus is cut by hand once annually, in early September: partially dried in the field and then cured at the homestead. Ten to fifteen centimetres of regrowth are necessary before the onset of the severe frosts. As with sweet clover in fuel-scarce areas, the stems may be used as fuel and the finer portions reserved as feed. Silage: silage-making is a more expensive technique but is popular in those parts of north-eastern China where Astragalus is the main fodder; Astragalus is less palatable than other fodders and a considerable amount of refuse may be left by the stock; silage made from Astragalus, however, is relished by the livestock and none is refused so ensiling has gained popularity locally despite the high labour requirement for chopping with the simple equipment available. Yields: vary from area to area but are generally in the 2.5 - 3 tonnes/hectare over the first three or four years and then fall off sharply; Astragalus stands thins out rapidly after the third season: these yields are reasonable for the rainfall but could probably be improved, as could longevity, if an improved fertiliser regime were used. Crop Improvement There is a potential for further selection within local ecotypes but the crop has lost importance since state-encouraged sowing of degraded watersheds declined and forage planting is now generally private. It grows wild as far north as the Mongolian Republic and Alaska so ecotypes which can produce seed in shorter growing seasons must be available. Pests&Diseases No major pests and diseases have been reported but older stands may suffer root damage from rodents. Links
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