With the aid of an electromagnetic induction gauge (EM38) and its mobile sensing system,spatial variability of soil salinity was analyzed in a field (200 hm²) typical of the Yellow River Delta for two critical seasons by using the univariate indicator Kriging procedure,and a soil salinity probability map at two different periods plotted based on the chosen criteria.Results indicate that apparent soil electrical conductivity is significantly correlated with salinity,and follows approximately the pattern of logarithmic normal distribution with some outliers in both seasons.Nested spherical models are fitted for indicator semivariance of the apparent soil electrical conductivity in both periods.Structural factors lead to isotropic spatial variability of soil salinity in autumn,while stochastic factors enhance anisotropy of soil salinity in spring,especially in the directions of north-south and eastwest.Soil salinity probability maps in different seasons show that the extent of soil salinization is generally high in the study area,and surface accumulation of soil salts during the drought season is the primary reason for this phenomenon.The joint application of the electromagnetic induction gauge and the indicator Kriging method provides a new approach to survey and quality evaluation of soil resources at different scales ranging from farms to regional levels,and reference in decision making for and management of agricultural water-soil resources.