花棒(Hedysarum scoparium)对雅鲁藏布江中游山坡流动沙地土壤理化性质的影响

The Effects of Hedysarum scoparium Restoration on Physical and Chemical Properties of Soil in Hillside Shifting Sandy Land in Middle Reaches of Yarlung Zangbo River, China

为深入了解人工固沙植被对山坡流动沙地土壤理化性质的影响,对雅鲁藏布江中游山南宽谷段山坡流动沙地固沙植被区(试验组)和裸地(对照组)土壤养分和机械组成进行测定,分析人工植被花棒(Hedysarum scoparium)对土壤养分和机械组成的改良效果。结果表明,与同一海拔高度对照组采样点土壤相比,花棒生长地土壤的pH值和全钾含量显著降低,全氮与有机质含量显著升高。土壤养分优劣程度表现为全钾>全氮>有机质>全磷。样地中土壤粒度以细砂粒和中砂粒为主,花棒生长地土壤中细砂粒含量(53.79%)较对照组土壤细砂粒含量(49.34%)有一定程度的提高,表明人工种植的花棒可以使土壤粒径不断细化,对植被表层土壤养分含量具有增加效果。样地中土壤粗砂粒、极粗砂粒、石砾占比与土壤养分含量均没有表现出显著相关性,黏粒和极细砂粒占比与土壤养分含量相关性较高。土壤颗粒越小对土壤影响越大,即对土壤养分的贡献越大。花棒作为一种根系发达的植物,对雅鲁藏布江中游山坡流动沙地土壤质地具有改良作用,可以作为当地一种较好的山坡流动沙地人工恢复植物。

To better understand the influence of artificial sand fixation vegetation on soil physical and chemical properties in the flowing sandy land of hill side,The soil nutrients and mechanical composition at the sand fixation vegetation restoration area(experimental group)and the bare land(control group)in the Shannan broad valley section were measured.The valley is located at the middle reaches of the Yarlung Zangbo River.The improvement effect of Hedysarum scoparium on the soil nutrients and mechanical composition was then analyzed.The results show that the pH and total potassium content of the Hedysarum scoparium rhizome soil decreased significantly,while the total nitrogen and organic matter content increased observably when compared with the control group soil at the same altitude.The ranking of quality of soil nutrients is total potassium>total nitrogen>organic matter>total phosphorus.The soil particle in the sample plot is mainly fine sand and medium sand,and the content of fine sand in the Hedysarum scoparium rhizome soil of flower stick(53.79%)is higher than that in the control group(49.34%),which indicates that the artificial flower stick can make the soil particle size continuously to be finer,and has an increasing effect on the nutrient content of the surface soil of vegetation.In the mechanical composition of soil,there was no correlation between coarse sand,extremely coarse sand,gravel and soil nutrients,however there was a high correlation between clay and very fine sand and soil nutrient content.The above findings show that the smaller the soil particles were,the greater the impact on the soil can be,which means the greater contribution to the soil nutrients.In conclusion,as a plant with developed root system,Hedysarum scoparium is helpful to improve the texture of the flowing sandy soil in the middle reaches of the Yarlung Zangbo River,and can be chosen as a high quality artificial restoration plant in the flowing sandy land.