Biological drainage Characteristics of Alakalized Desert Soils in Northwestern China |
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出 版 社:Journal of Arid Environments |
发表时间:2002/12 |
台 站:
阜康荒漠生态试验站
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作 者:Chengyi Zhao |
点 击 率:2556 |
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关 键 字:null |
摘 要:null |
关 键 字(英文):Alakalized Desert Soils, Biological Drainage, Soil Sodicity and SAR |
摘 要(英文):In one study, 92% of cored soil samples of the affected fields showed SAR values above 5, while 42% had values above 15. One ameliorative approach, bio-drainage using different desert vegetation, was used to control the high water tables and reverse the observed salinity/sodicity trends in the border area of the Manas Alluvial Fan. Results of this study indicate that both conventional and biological drainage is attractive options for controlling the local hydrology and limiting or diminishing salinity- sodicity trends. |
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Soil salinity/sodicity surveys in the area showed relatively high levels of the Sodium Adsorption Ratio (SAR) in the upper soil layers. 92% of cored soil samples of the affected fields showed SAR values above 5, while 42% had values above 15. The bio-drainage using different desert vegetations, was used to control the high water tables and reverse the observed salinity/sodicity trends in the border area of the Manas Alluvial Fan. The groundwater table dropped to below 2.28 m in the summer of the fifth year, which was sufficient to prevent secondary salinization. A related plot study showed that desert plants consumed large amounts of soil water while leaving most of the salts behind. The salt contents of leaves and young branches were different for different vegetation. Soil profile salt distributions for the deep-rooted and shallow-rooted systems were different in two of the three years after planting. Commercial forestry of Lycium barbarum and other timber products under current conditions, and without irrigation, appears a viable agricultural alternative that could bring higher returns than for wheat or cotton. Results of this study indicate that both conventional and biological drainage is attractive options for controlling the local hydrology and limiting or diminishing salinity- sodicity trends. |