内蒙古河套灌区土壤盐渍化特征OA

This study investigates the variability characteristics of soil salinization in the Hetao Irrigation District of Inner Mongolia and determines the types of soil salinization.Correlation analysis and principal component analysis were employed to study the salinization characteristics of the 0-100 cm soil profile in the area.The results indicate that:① The overall soil in the study area is alkaline,with alkalinity increasing with depth.The pH of the soil in the 10～100 cm layer is significantly higher than that in the surface 0～10 cm layer(P<0.05).Soil pH demonstrates weak variability and is evenly distributed spatially.The total dissolved salt concentration decreases with increasing soil depth,exhibiting a typical epilimnetic distribution:high concentration in the surface layer and low concentration in the deeper layers.Variability in total dissolved salts is strong in the upper 0～40 cm layer and moderate in the lower 41～100 cm layer,showing spatial differences with depth.② The main anions and cations in the study area's salinity are SO42-and Na++K+,respectively.The mass ratio of Na+and K+accounts for over 60%of the total cation mass,significantly higher than that of other cations(P<0.05).Additionally,the mass ratio of sulfate ions constitutes 90%of the total anion mass,significantly exceeding that of other anions(P<0.05).The ion mass ratios,from high to low,are SO42-,Na++K+,Ca2+,Mg2+,Cl-,HCO3-,and CO32-.With increasing soil depth,the mass ratios of all ions,except CO32-,gradually decrease,a trend consistent with the total dissolved salt concentration.③ Correlation and principal component analyses reveal that SO42-,Cl-,Na++K+play dominant roles in soil salinization in the study area,with sulfate salts being the primary salts present.pH and CO32-primarily influence soil alkalinity,defining the alkaline characteristics of the soil.This in-depth study identifies the main factors affecting soil salinity characteristics in the Hetao region of Inner Mongolia,providing a solid theoretical foundation for managing local saline-alkaline land.