Soil density-porosity relationship across land use systems in the mountainous ecosystem of the Pir Panjal region, Jammu and Kashmir

This study investigated the effects of four land use systems namely, Natural Forest; Pasture Land; Terraced Maize and Upland Rice on selected soil physical properties in the mountainous valley of Pir Panjal, Jammu & Kashmir. Geo-referenced soil samples were collected from three depth intervals (0–15 cm, 15–30 cm, and 30–60 cm) using a stratified random design and undisturbed cores were obtained to determine bulk density. Conducting sampling across steep terrain, variable elevations, and limited field access posed major logistical challenges. Ensuring uniform sampling precision in highly heterogeneous soil conditions of a fragile mountain ecosystem further required meticulous field and laboratory procedures. Results revealed a clear gradient in soil structural stability corresponding to land use intensity. Natural Forest soils had the lowest bulk density and highest porosity, reflecting superior structural conditions, while intensively cultivated Upland Rice soils showed the highest bulk density and lowest porosity. Pasture and Terraced Maize systems exhibited intermediate values. Land use exerted a significant influence (p ≤ 0.05) on soil physical properties, whereas soil depth and its interaction with land use were not statistically significant. Bulk density and porosity emerged as sensitive indicators of soil physical degradation linked to land use. This study contributes valuable empirical evidence on the vulnerability of Himalayan soils to intensive land use transitions. It highlights the critical role of permanent vegetation cover and organic matter in preserving soil physical health and reinforces the need for conservation-focused land management to ensure long-term soil sustainability in this vulnerable mountain ecosystem.