Directive reference – Art 7; Annex I
A descriptor is a soil property or process assessed for soil health; an indicator is the measured variable used for it. Annex I groups them by how they are assessed.
Part A (criteria set at Union level) covers three descriptors. Salinisation is measured by electrical conductivity in a saturated paste extract, with a target below 4 dS/m; naturally saline, regularly flooded and sea-spray areas are exempt. Loss of soil organic carbon uses national targets for organic soils and, for mineral soils, a SOC/clay ratio above 1/13 with possible corrective factors; unmanaged natural soils are exempt. Subsoil compaction uses subsoil bulk density thresholds by texture class, for example below 1.80 g/cm³ for sandy loam and below 1.47 g/cm³ for clay.
Part B (criteria set by Member States) covers five descriptors. Excess nutrients is assessed by extractable phosphorus against a national maximum. Soil erosion uses the erosion rate against a national maximum. Soil contamination covers heavy metals (for example As, Cd, Pb, Hg, Zn) and selected organic contaminants, taking natural background into account. Reduced water retention and infiltration uses water holding capacity, hydraulic conductivity and air capacity against national minimum thresholds. Loss of SOC (stocks) uses minimum SOC values by texture, linked to national LULUCF targets.
Part C (descriptors without criteria) covers five descriptors. Excess nutrients is also described by total nitrogen and the SOC/N ratio. Acidification uses soil pH, with base saturation optional. Topsoil compaction uses topsoil bulk density. Loss of soil biodiversity uses DNA metabarcoding of fungi and bacteria, with optional earthworms, nematodes and springtails. Soil contamination also covers PFAS (PFAS-21, PFAS-43 or a national selection) and selected pesticides and their metabolites.
Part D (sealing and removal) uses sealed and removed area (km² and % of territory), net annual sealing, settlement area and land-use change to and from it, and optionally the land recycling rate and fragmentation.