Spatial variation characteristics of soil salinity in typical oasis region

Soil salinization constraints the sustainable development of oasis agriculture in arid area. This study focus on exploring spatial variation of soil salinity in typical oasis region by geostatistical method combined with GIS technique. The main results indicated that soil salinity of 0-30cm topsoil showed strong variability while that of deeper soil layers showed moderate variability. Soil salinity of each layer (0-30, >30-60 or >60-100 cm) demonstrated moderate spatial autocorrelation, and the spatial correlated distances were in the range of 24-28 km. Salinity of certain grade for different layers approximately occupied the same orientation. In every soil layer, the non-salinized soil area occupied a dominant area, accounting for more than 69% of the total, with mild salinized soil followed, accounting for 19% to 30% of the total area, and the moderate salinized soil area of was less than 3.4% while heavy salinized soil only in the 0-30 cm soil layer had very small distribution. With soil depth increasing, the area of non-salinized or moderate salinized soil gradually reduced, while mild salinized soil area increased. This study has important theoretical values for oasis agriculture in arid area and sustainable utilization of soil resources in regional scale, and thus has clear practical application prospects.