This study examines the stoichiometric relationships between soil organic carbon (SOC), phosphorus (P₂O₅), and pH in mountain-brown soils of the Hisar and Turkestan ranges (Central Asia). Soil profiles were sampled across watershed, slope, and footslope positions to assess vertical and regional patterns. SOC and available phosphorus (expressed as P₂O₅) decreased with depth across all soil subtypes, whereas pH and carbonate content increased concurrently along the profiles. Although surface SOC concentrations were comparable between regions, significant differences were observed in phosphorus availability and related stoichiometric indices (C:P₂O₅ and N:P₂O₅). Soils of the Hisar range showed indicators of stronger phosphorus-related constraints, expressed by steeper declines in available P fractions and higher N:P₂O₅ ratios. These findings suggest that phosphorus availability and soil chemical conditions, rather than SOC concentration alone, play a key role in shaping stoichiometric conditions potentially associated with SOC stabilization in mountain ecosystems. The results emphasize the importance of integrating nutrient stoichiometry into assessments of SOC dynamics in carbonate-dominated mountain soils.