Spatial heterogeneity of soil potassium geochemistry: A case study from Tianfu New Area, Chengdu, China

Urban-rural integration zones, situated at the interface between urban and rural environments, undergo profound alterations in arable soil quality attributed to rapid urbanization and intensified agricultural practices. However, there is still insufficiency research on potassium depletion from a spatial perspective, despite the increasing demand for vegetables. To address this gap, the spatial distribution characteristics of soils potassium in Tianfu New District, Chengdu Plain, China, were studied based on geochemistry, geostatistics and Earth system science. The results showed that: (1) Spatial heterogeneity existed in both soil total potassium (STP) and soil available potassium (SAP). However, there was no obvious spatial correlation between STP and SAP, and their spatial extents exhibited minimal overlap. (2) The STP levels are mainly affected by the altitude, slope, stratum exposure and geological background. (3) The SAP content is obviously affected by anthropogenic input, and the enrichment is significantly affected by fertilizers. This study reinforces the notion that the human intervention has strongly affected arable soil quality. The availability of fertilizer (e.g., potash) may significantly affecting food security within China.