Influence of Vegetation Cover and Soil Properties on Water Infiltration: A Study in High-Andean Ecosystems of Peru

Water infiltration into soil is a key process in regulating the hydrological cycle and sustaining ecosystem services in high-Andean environments. However, limited information is available regarding its dynamics in these ecosystems. This study evaluated the influence of three types of vegetation cover and soil properties on water infiltration in a high-Andean environment. A double-ring infiltrometer, the Water Drop Penetration Time (WDPT, s) method, and laboratory physicochemical characterization were employed. Soils under forest cover exhibited significantly higher quasi-steady infiltration rates (is, 0.248 ± 0.028 cm·min−1) compared to grazing areas (0.051 ± 0.016 cm·min−1) and agricultural lands (0.032 ± 0.013 cm·min−1). Soil organic matter content was positively correlated with is. The modified Kostiakov infiltration model provided the best overall fit, while the Horton model better described infiltration rates approaching is. Sand and clay fractions, along with K+, Ca2+, and Mg2+, were particularly significant during the soil’s wet stages. In drier stages, increased Na+ concentrations and decreased silt content were associated with higher water repellency. Based on WDPT, agricultural soils exhibited persistent hydrophilic behavior even after drying (median IQR from 0.61 0.38 s to 1.24 0.46 s), whereas forest (from 2.84 3.73 s to 3.53 24.17 s) and grazing soils (from 4.37 1.95 s to 19.83 109.33 s) transitioned to weakly or moderately hydrophobic patterns. These findings demonstrate that native Andean forest soils exhibit a higher infiltration capacity than soils under anthropogenic management (agriculture and grazing), highlighting the need to conserve and restore native vegetation cover to strengthen water resilience and mitigate the impacts of land-use change.