[Spatial variability of soil nutrients and salinity in coastal saline-alkali land based on belt transect method].

A north-south transect was established in the saline-alkali land of Yellow River old course at Diaokou of northern Yellow River Delta, Shandong Province of East China to analyze the spatial distribution characteristics of soil nutrients and salinity and related affecting factors by using geostatistics method. In the study area, the nugget/still of soil organic matter, total nitrogen (TN), available phosphorus (AP), and available potassium (AK) contents and soil salinity were 0.38, 0.40, 0.50, 0.32, and 0.34, respectively, which demonstrated that these five parameters were moderately spatial dependence. The soil organic matter and TN contents in this transect had a similar distribution pattern, soil AK content was highly correlated to soil salinity, while soil AP content presented a fluctuated distribution. According to the comprehensive analysis of soil organic matter content and salinity, this transect was classified into three types, i.e., high salinity and low fertility, high salinity and high fertility, and low salinity and high fertility. The spatial distribution pattern of the five soil parameters was closed related to the soil parental material, land use pattern, distance to sea, and road block.