Study on Soil Salinization Characteristics of Farmlands Along West Trunk Canal in Ningxia Based on Redundancy Analysis

Abstract

Based on the statistical analysis and redundancy analysis on the soil sampling points along West Trunk Canal in Ningxia of China, the spatial distribution characteristics and relations among total salt content, pH value and salt ions’ composition at different depths are obtained. The correlation coefficients, eigenvalues and interpretation variances of salt ions in each soil layer are analyzed and discussed. According to the analysis, it can be concluded that the farmlands along West Trunk Canal is severely salinized, especially for the soil near the shallow surface. The redundancy analysis results show that in the 0–80 cm soil layer, the angles between CO32- and pH value and HCO3- and pH value, are smaller than other environmental factors, indicating that soil pH value is significantly affected by the content of CO32- and HCO3-, and they are positively correlated. K+ and Cl- have the smaller and acute angle with total salt, indicating that total salt of the soil is significantly affected by the content of K+ and Cl- and they are also positively correlated. Different from others, in the 80–100 cm soil layer, pH value is significantly affected by the content of Na+ and the total salt of the soil is significantly affected by the content of Mg2+, Cl-, CO32- and HCO3-.