Exploring the spatial distribution and influencing factors of soil PH value of cultivated land in Sichuan Province

Soil pH is a crucial indicator which greatly reflects the cultivated land fertility. Exploring its spatial distribution characteristics and influencing factors is essential for the sustainable utilization of cultivated land. This study characterizes the spatial distribution and influencing factors of pH value of cultivated land in Sichuan Province, China. In particular, spatial autocorrelation, cold hot spot analysis, and geographic detectors were applied in this study. Results revealed that: (1) the pH values of cultivated land soil in Sichuan Province ranged from 3.53 to 8.88, with a mean value of 6.78. Alkaline and slightly acidic soils accounted for the majority, representing 59.5% of the total samples. The overall variability of soil pH in the study area was moderate, with both structural and random factors contributing to its spatial variation. (2) The spatial distribution of soil pH in Sichuan Province exhibited a decreasing trend from northwest to southeast. Neutral soil predominated in the plain and basin regions, while alkaline soil was primarily found in the southeastern part. (3) The spatial variation of soil pH in Sichuan Province demonstrated significant positive spatial clustering. High-value aggregation areas were mainly located in the Chengdu Plain and northern regions, whereas low-value aggregation areas were concentrated in the southern part of the Chengdu Plain and eastern areas. (4) The relative contributions of different factors to soil pH in arable land of Sichuan Province ranked as follows: precipitation > available phosphorus > available potassium > elevation > temperature > organic matter > NDVI > topsoil thickness > total nitrogen.