Spatial variability and appropriate sampling quantity of soil salinity for various depth layers(0~20 cm

20~60 cm

60~100 cm

and 100~140 cm) was measured and analyzed by using statistics and geo-statistics

which was performed in an approximately 520 hectare field in the Yellow River Delta.The results indicated that soil salinity for all depth layers were generally high and salt accumulation at the surface soil layer was significant;Soil salinity for all depth layers exhibited moderate spatial variation and moderate spatial autocorrelation resulting from compound impact of structural and stochastic factors.The spatial distribution maps of soil salinity interpolated by Kriging interpolation showed apparently that the spatial distribution of soil salinity was mostly controlled by micro-topography and climatic conditions

and there existed spatial correlativity between soil salinity distribution maps of different depth layers.Analysis on the appropriate sampling quantity

which was determined by using Cochran and distributed sampling methods respectively

showed that distributed sampling methods could reduce the appropriate sampling quantity effectively

the appropriate sampling quantity for rational distributed sapling was the most reasonable and practical

and rational distributed sampling could furthest reduce some 35% of the appropriate sampling quantity compared with weighing distributed sampling.The research results can serve as a theoretical and technical basis for the scientific management

amelioration

and utilization of saline soils in the Yellow River Delta.