A Study on Spatial Heterogeneity of Soil Salinity in the Typical Area of Yutian Oasis

Spatial heterogeneity of soil salinity in the typical area of Yutian oasis was analyzed by using geostatistics.Results indicated that soil salinization in Yutian oasis was severe and soil salinity accumulated in surface soil layer.The variational amplitude of soil salinity in surface soil layer was the highest because of the disturbance of human activities.The spatial correlation of soil salinity in the 0—5 cm soil layer was strong;in the 5—30 cm soil layer,in the second place;and in the 30—70 cm soil layer,relatively low.In the horizontal direction from east to west,soil salinity in the 0—30 cm soil layer manifests an increase and decrease trend,while soil salinity in the 30—70 cm soil layer gradually declined.Soil salinity was high in the northern and southern parts of the study area and low in the interior part.In vertical direction,soil salinities in saline land,highly coved grassland and medially coved grassland were relatively high and gradually decreased from soil surface to lower soil layer.Soil salinity in saline land was the highest,the variational amplitude of soil salinity in highly coved grassland was greater than that in medially coved grassland,soil salinities in farmland and lowly coved grassland were relatively lower with low variational amplitudes.The main factor for the spatial heterogeneity of soil salinity in the oasis was the difference of soil and water movement in different landforms and land uses.