Assessing soil health requires indicators that capture both the structural condition of soils and their capacity to perform essential ecosystem functions. Soil structure is a key component of soil health because it influences water flow, aeration, root development, carbon storage, and biological activity.
However, assessing soil structure holistically remains a challenge.
Detailed metrics like X-ray computer tomography-derived pore geometry or saturated hydraulic conductivity (Ksat) provide valuable insights into soil structure and function but are costly and time-consuming to measure and rely on delicate undisturbed sampling. The Visual Evaluation of Soil Structure (VESS) offers a rapid field-based soil structural quality assessment, yet it remains unclear whether relationships previously reported between VESS and established structural indicators also hold across contrasting land-use types and soil properties, leaving its potential as a universal soil health indicator unknown.

Consequently, we investigated whether VESS supports the functional assessment of more detailed structural soil metrics across different land uses and soil textures. In this study, 66 sites representing cropland, grassland, and forest ecosystems across Switzerland were sampled.
At each site, VESS was performed and four undisturbed soil cores were collected from the topsoil for assessment of CT-derived macropore metrics and soil hydraulic properties. VESS scores were compared with CT-derived macroporosity, macropore connectivity, Ksat, soil texture, pH, bulk density, and soil organic carbon.

VESS scores were well distributed across both land-use types and textural classes and did not show a consistent trend with either factor alone. This indicates that visual soil structural quality cannot be explained by land use or texture in isolation and suggests that VESS can be applied across a broad range of soil conditions.
Sites with favorable VESS scores generally exhibited larger and better connected macropore networks resulting in higher Ksat-values, indicating that several relationships previously reported in agricultural systems also persist across contrasting land-use types and textures, although their interpretation depends on the dominant type of soil structure formation. Our findings suggest that VESS provides a rapid first assessment of soil structural quality and supports the interpretation of more detailed soil health indicators. The value of VESS-application is greatest when its interpretation is combined with basic soil properties (to assess conditions of structure formation), making it a promising indicator for efficient large-scale soil health monitoring across different land use types.