Abstract:Soil salinization is one of the main causes of land degradation, and it affects both sustainable and environmental improvements in arid areas. In this study, we analyzed and exploited the spatial variability of saline-alkaline soil types in the study area under different currently popular saline-alkaline soil classification standards to obtain important information for land reclamation or restoration according to local conditions.The Manas River Basin, which was reclaimed nearly 50 years ago, was selected as the study area because it is a typical mountain-basin structure in western China. Soil properties (pH, soil salinity, and ions) were used as indicators to analyze the spatial characteristics of the distribution of different land-use types of non-agricultural land (abandoned farmland, salt-affected land, bare soil, and desert) with both statistical and geo-statistical methods. There were two popular classification standards used in this paper:The United States Salinity Laboratory classification and Russia Anion classfication (1) With respect to surface soil (0-20 cm), 68% of the surface samples were non-saline soil, and different types of saline soils (slight, moderate, severe and extreme saline soils) classified by the first classification were distributed all over the overflow zone, alluvial plain, and dry delta areas.From south to north, soil salinity increased, decreased, and then increased. The variation in soil salinity was low and affected by random factors, while pH increased overall with moderate variations, affected by both random and structural factors. The types of(Cl/SO42-)anion soil types were classified into four classes:the sulfate, chloride-sulfate, sulfate-chloride and chloride soils, while (CO32-/SO42-) anion soil types were classified into three classes:the sulfate-soda soil,soda soil and soda-sulfate soil. The surface anion soil of the overflow zone area was chloride soil; other anion soil types were from sulfate-chloride soil type to chloride-sulfate soil; sulfate soil,soda saline soil type, exhibited a normal distribution from south to north. The variation in anions was slight and moderate, which means that the influence of random and structural factors was the same as that described in The United States Salinity Laboratory classification. (2) One-way analysis of variance of the characteristics of the saline soil types was carried out for 0-100 cm soil layers in the five landscapes (alluvial fan, alluvial plain, overflow zone, dry delta, and desert) showed that the soil salt content accumulated over the surface, pH increased from south to north either, and the most significant landscape type was the overflow zone. The anion soil types in the vertical (from top to bottom) profile of the overflow zone landscape changed from sulfate-chloride type to chloride type, while the anion soil types of the alluvial plain and dry delta landscapes were chloride-sulfate type; other anion soil types were distributed over the alluvial fan and desert. This study of the spatial heterogeneity of saline-alkaline soil types will provide scientific guidance for government to manage soil resources.