Soil quality responses of a tropical Andisol to contrasting land-use systems: Insights from multiple indexing...

Andisols are among the most productive and carbon-rich soils in tropical highland regions, yet their capacity to sustain ecosystem functions is highly sensitive to land-use and management. In this study, we assessed the impact of four contrasting land-use systems - intensive farming, pasture-oat transition, improved pasture, and silvopastoral systems - on soil quality of a tropical Andisol in the Colombian Andes. Additionally, we evaluated the performance and sensitivity of four soil quality approaches: total dataset (SQI1), principal component analysis-based minimum dataset (SQI2), revised minimum dataset (SQI3), and correlation-based weighting (SQI4). A total of 23 soil indicators were measured across 0-30 cm depth and integrated using the four approaches. Our results revealed significant decreases in biological and physical indicators in intensive farming system, including a 29 % reduction in soil organic carbon (C) and 16 % in microporosity relative to improved pasture system. In contrast, improved pasture and silvopastoral systems supported higher enzymatic activity and C stocks, demonstrating their role in enhancing soil structure and long-term C sequestration. Among indices SQI2 and SQI3 demonstrated greater sensitivity in detecting land-use effects compared to other. SQI2, which relies on only seven indicators, demonstrated the highest sensitivity and the strongest correlations with independent soil properties, highlighting it as a robust and cost-effective tool for monitoring soil quality in Andean soils. Our findings underscore the vulnerability of tropical Andisol to unsustainable management and support the application of minimum dataset-based indices for efficient and functionally meaningful soil quality assessment in tropical agroecosystems.