Spatial Variability of Soil Bulk Density in the Yellow River Delta

Spatial variability of soil bulk density for various layers was measured and analyzed by using traditional statistics and geo-statistics,which was performed in characteristic field in the Yellow River Delta.The results indicate that soil samples for all layers showed compaction trend to some extent,and the variation in bulk density for all layers was rather weak.Soil bulk density all exhibited moderate spatial autocorrelation resulting from compound impact of structural and stochastic factors.Fractal dimension proved that bulk density for all layers showed weak spatial dependency,and the variability of claypan in depth and distribution was the crucial reason of resulting in the spatial heterogeneity of bulk density.The spatial distribution maps interpolated by Kriging interpolation showed that spatial distribution of salinity was closely related to soil texture,and bulk density for all layers exhibited the similarity in spatial distribution in a certain range.The further correlation analysis indicate that soil bulk density for all layers was significantly correlated with each other.The spatial distribution maps of bulk density,which were obtained through the study on spatial variability,can serve as a scientific basis for the regional management,harness and amelioration of moderate-and-low-yield farmlands and obstacle soils in the Yellow River Delta.