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出 处:《中国草地》1993年第4期4-8,共5页Grassland of China
基 金:国家自然科学基金
摘 要:对羊草草原割草强度与土壤盐渍化关系进行的两年研究表明,割草次数增加和留茬高度过低均使土壤表层含水量下降,土体内上升水流加大,土体下部盐分随上升水流到达地表积聚,造成土壤盐渍化;pH值上升,碱化度增高,植物群落生物量下降;优质牧草数量减少,植物群落组成发生变化;耐盐碱植物种类增多,草地质量下降。The relation ship between cutting intensity and soil salinization was discussed in this paper on the bases of an experiment in 1990—1991. The results of the experiment showed that the water content in the soil decreased with the increase of cutting intensity. The salts that remained under the lower soil layer was brought up to the soil surface with the up—water fliw and accumulated there, resulting in increases of pH and ESP (Na) in the soil. As well as the product of plant was decreased, the composition of plant community changed because of the degeneration of environment. The amount of grasses of high quality decreased and plants that resist to salinity reased, As a result, the quality of grassland degenerated.
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