Spectroscopic assessment of soil organic matter in urban soils under diverse land use systems

Soil organic matter (SOM) is a key indicator of soil health in cities. However, its monitoring in heterogeneous urban landscapes is still constrained by the cost and time requirements of conventional analyses. Visible and near-infrared (Vis-NIR) spectroscopy offers a rapid, non-destructive, and cost-effective alternative, but its use in urban soils and its integration with emerging measurement standards remain limited. In this study, we evaluated the ability of Vis–NIR spectroscopy to predict SO