🌱 Public methodology
SoilDiag — Living Soil diagnostic
The BIOM365 tools' methodology is published and grounded, indicator by indicator, in the field's reference work: each tool sets out what it measures, how it computes it, its sources and its limits.
Use the tool →What it measures
The biological health of a soil at a given moment (not its intrinsic « quality »), through field indicators achievable without a laboratory. The quality / health distinction and the need for guide-values are set out by Cerema.
How it computes
A weighted sum of indicators aligned with the 4 soil functions of the MUSE grid (biodiversity reservoir, biomass, carbon, water regulation), returning a per-function profile in addition to the score. Each class maps to a published guide-value (e.g. earthworms: order of magnitude ~280 ind./m² in urban settings). Protocols: structure (VESS), earthworms (OPVT), infiltration (mini-Porchet), compaction (penetrometry), texture (textural triangle), organic matter (colorimetry).
≥ 3 points per homogeneous zone, imposed season window (excluding drought / frost / waterlogged soil); outside the window or in extreme moisture, the earthworm and infiltration indicators are flagged unreliable. Non-lethal earthworm counting. Orientation diagnostic.
Standardised multi-plot aggregation + physico-chemical composite, moisture measurement, enriched bio-indicators (earthworm ecological categories, epigeal fauna), optional laboratory analyses. Feeds the « initial soil state » and the ecological soil quality monitoring (initial state / impact assessment).
Common methodological foundation
- Verifiability — a data point carrying a score must be provable — mandatory in PRO.
- Conservativeness — without evidence, we do not overestimate; declarative input is flagged.
- Consistency — any time-series data is comparable — bounded observation effort.
Two quality indices accompany each score: a reliability index (input completeness; below a threshold the score reads « not computable ») and a confidence index (traces the source of each value; by convention, the lowest of its components' indices).
On screen: a 0-100 score + a one-word label + a colour. Performance axis (Excellent / Good / Fair / Low / Critical), thresholds aligned with the internal grade so a displayed score and its history never contradict each other. Exposure axis for BiodivPass and TerraLink (Contained exposure → Immediate action).
Thresholds and weightings rely on the guide-values and reference frameworks cited, and are consolidated continuously with the scientific committee (Biodiversity Standard Council).
Stated limit
A point-in-time state diagnostic; texture and organic matter estimated by eye (inter-observer variability); the fauna guide-values are comparative orders of magnitude, not regulatory thresholds.
Sources & references
- Cerema — Indicators for soil quality
- MUSE project — soil functions & indicators
- VESS — Visual Evaluation of Soil Structure (SRUC)
- OPVT — Observatoire Participatif des Vers de Terre
- Plante & Cité — Acting for urban soils
- ACT Biodiversity — methodology (ADEME/OFB)
- Avoid-Reduce-Offset sequence (OFB)
The measurement protocols rely on the recognised methods above. Thresholds and weightings are consolidated continuously with the scientific committee (Biodiversity Standard Council).