Introduction: Soil salinization and alkalinization in the arid zones of southern Peru pose major challenges to agricultural sustainability, particularly in the olive orchards of Bella Unión, where irrigation relies on surface and groundwater of variable quality. This study aimed to assess soil quality and its spatial variability to support site-specific management in olive (Olea europaea L.) orchards. Methods: A total of 160 composite soil samples (0–30 cm) were collected from representative olive orchards and analyzed for pH, electrical conductivity (ECe), organic matter (OM), available phosphorus (Pav), available potassium (Kav), texture, and calcium carbonate equivalent (CCE). The Soil Quality Index (SQIw) was calculated and combined with multivariate and geostatistical analyses to identify key soil quality indicators and characterize their spatial variability. Results: Soils showe...