天山西部伊犁河流域土壤盐分特征

采用相关分析法与主成分分析法研究了伊犁河流域土壤盐分特征.结果表明:研究区域耕层(3～20 cm)土壤53.68%样地为非盐渍化土壤,18.38%为轻度盐渍化,13.97%为中度盐渍化,8.82%为重度盐渍化,5.15%为盐土;土壤盐渍化类型以硫酸盐渍土为主,占68.41%.盐分组成中,阴离子以SO₄2-和Cl-为主,阳离子以Na+和Ca2+为主;土壤盐分与Cl-和SO₄2-分别呈极显著、显著正相关关系,揭示了土壤盐分大小与w(Cl-)和w(SO₄2-)有关;表层(0～3 cm)土壤盐分平均值占0～60 cm土层盐分平均值的60.19 %,即土壤盐分垂直分布呈现强烈表聚性.主成分分析结果表明,盐分,w(Cl-),w(SO₄2-),w(Mg2+)与w(Ca2+)可作为研究区域土壤盐渍化状况的特征因子.不同土地利用类型条件下,耕层土壤盐分平均值从高到低依次为草地、旱田、稻田、林地.不同灌溉条件下,井灌农田耕层土壤盐分平均值为1.12 g/kg,渠灌农田耕层土壤盐分平均值为0.73 g/kg,渠灌农田耕层土壤盐分平均值比井灌农田小0.39 g/kg.不同时期耕层土壤盐分平均值从高到低依次为非灌溉期、夏灌期、秋灌期. 

Characteristics of Soil Salinity in Ili River Valley,Western Tianshan Mountains

The characteristics of soil salinity in the Ili River Valley,Western Tianshan Mountains,China,were studied based on correlation analysis and principal component analysis methods.Results of the study indicated that:53.68% of soil samples from the root zone soil layer (3-20 cm) were non-salinized,while 18.38% were slightly salinized,13.97% were moderately salinized,8.82% were strongly salinized and 5.51% were saline soils.The types of soil salinization were mainly sulphate saline soils,occupying 68.41%.Anions were mainly SO₄^2- and Cl^- while cations were mainly Na⁺ and Ca²⁺.Soil salinity showed significantly positive correlation with the concentration of Cl^- and SO₄^2-,indicating that the degree of soil salinity depends on the concentration of Cl^- and SO₄^2- of soil to a certain extent.The salinity of the surface soil layer (0-3 cm) occupied 60.19% of the salinity of the 0-60 cm soil layer,indicating that the soil salinity was distributed mainly at the top soil layer.Results of principal component analysis indicated that the salinity,Cl^-,SO₄^2-,Mg²⁺ and Ca²⁺ concentrations could be the characteristic factors for expressing soil salinization in the study area.The abundance of salinity of the root zone soil layer for different land use types was in the following order:grassland>glebe field>paddy field>forest land.Under different irrigation conditions,the salinity of the root zone soil layer of farmlands irrigated with groundwater and surface water was 1.12 g/kg and 0.73 g/kg respectively.However,the salinity of the root zone soil layer of farmlands irrigated with surface water was 0.39 g/kg lower than farmlands irrigated with groundwater.The abundance of salinity of the root zone soil layer for different periods was in the following order:non-irrigated period>summer irrigation period>autumn irrigation period.