土壤水盐信息与容重在垂直方向的空间结构性研究

Space Structure of Soil Water and Salt Information and Density in the Vertical Direction

通过对土样含水率和EC值的测定，运用地质统计学理论研究在垂直方向上土壤水盐的空间结构性及容重的变化情况。统计分析表明，水分的变异性小于盐分的变异性。容重在垂直方向上的离散性和空间变异性都很小。容重在距地表2．0m深垂直剖面内的均值为1．48g／cm^3。运用OK法估计区域水盐信息，结果表明，试验田内的测点与微成水试验田外的测点土壤含水率在垂直剖面上的分布，主要区别是干燥层位置明显下移，表层和底层含水率变化范围基本保持一致。试验田内的测点EC分布基本上从0～80cm深度内为单调递减，80cm以下EC值基本上为一常数。微咸水试验田外的测点，剖面上存在有明显的变化，在距地面约90cm深度处有EC峰值。土壤容重在80cm以下深度土层基本上稳定，大约在1．45g／cm^3左右。与统计分析均值计算结果1．48g／cm^3非常接近。

Through the determination of the soil moisture content and value of the EC, we use the geostatistics theoretical to research the space structure of soil water and salt in the vertical direction and changes of density in the vertical direction. Statistical analysis showed that the variability of water is less than the salt. The Bulk density of the dispersion and spatial variation is very small in the vertical direction. The av- erage bulk density is 1.48 g/cm^3 in the 2.0 m deep vertical profile. We used the method of OK to estimates the information of regional water and salt The results showed that, between the II and I point the distribution characteristics and main differences of soil moisture content in the vertical profile is that the position of the drying layer is obviously lower than the level positions, surface and bottom water content changes in the scope of the basic line. Basically the EC distributing of II point keep the monotone decreasing state largely from 0 to 80 cm depth. Below 80 cm depth EC is a constant value basically. On the side profile of the I test pits, there is a clearly changes and EC arrive at the peak value in about 90 cm depth below the ground. Soil bulk density is basically stable in the following 80 cm soil depth and the soil bulk density is about 1.45 g/cm^3 , which is very close to the results of the statistical analysis 1.48 g/cm^3