Spatial simulation of soil total potassium in regional scale for Loess Plateau Region

To understand the spatial heterogeneity of soil total potassium in regional scale for Loess Plateau Region and its influencing factors, In the study, a total of 283 sampling sites were investigated in order to estimate the spatial variation of soil total potassium (STK) across the entire Loess Plateau (620, 000 km²). Spatial simulation and classical linear regression were used to quantify the relationships between STK and bulk density, clay and silt content, soil pH, precipitation, temperature, and elevation. The best state-space models explained more than 97% of the STK variation, while the best linear regression model explained less than 26% of the STK variation. The results showed that all the state-space models described the spatial variation of STK much better than that of the corresponding linear regression models. Spatial simulation is recommended as a useful tool for quantifying spatial relationships between soil properties and the other environmental factors in large-scale regions.