EN ISO 20130:2020 - Overview
EN ISO 20130:2020 (ISO 20130:2018) is a CEN-adopted international standard for assessing soil quality by measuring patterns of enzyme activity in soil samples. The method uses colorimetric substrates in micro-well (96‑well) plates to determine multiple hydrolase activities (arylamidase, arylsulfatase, β‑galactosidase, α‑ and β‑glucosidase, N‑acetyl‑glucosaminidase, acid/alkaline/global phosphatases, urease). Measurements are made after controlled incubation (typically at 25 °C ± 2 °C or 37 °C ± 2 °C), reaction stoppage, centrifugation and absorbance reading with a microplate spectrophotometer.
Key topics and technical requirements
- Scope: simultaneous (or individual) measurement of several soil hydrolases using colorimetric assays to profile microbial extracellular enzyme activities relevant to C, N, P and S cycles.
- Principle: incubation of soil extract with colorimetric substrates in micro‑well plates; color development is quantified spectrophotometrically.
- Enzymes covered: ARN, ARS, β‑GAL, α‑GLU, β‑GLU, NAG, PAC, PAK, PHOS and URE (see standard for enzyme codes).
- Laboratory conditions: defined incubation temperatures, standardized substrate and standard preparation, stopping procedure, centrifugation and supernatant transfer prior to absorbance measurement.
- Calibration & calculations: establishment of calibration curves (e.g., p‑nitrophenol or equivalents), expression of results and validity criteria are specified.
- Quality assurance: includes interlaboratory validation, intralaboratory checks and informative annexes summarizing ring test results and method validation.
Applications and users
Who uses EN ISO 20130:2020:
- Environmental and soil testing laboratories conducting soil quality monitoring.
- Ecotoxicology and environmental chemistry teams assessing toxicant impacts on soil microbial function.
- Agricultural researchers and land managers tracking soil health, seasonal changes and management effects.
- Regulatory agencies and consultants performing contaminated site assessments or chemical testing.
Practical uses:
- Detecting harmful effects of pollutants or anthropogenic agents on soil enzymatic function.
- Comparing contaminated sites against control soils.
- Researching microbial-mediated decomposition and nutrient cycling (C, N, P, S).
Related standards
- ISO 18400‑206 (soil sampling for microbiological assessment) - referenced for sample collection, handling and storage.
- EN ISO 20130 includes informative Annex A (validation/intralaboratory tests) and Annex B (international ring test).
EN ISO 20130:2020 provides a standardized, reproducible approach for measuring soil enzyme activity using colorimetric microplate assays, supporting robust soil quality assessment, ecotoxicology studies and environmental monitoring.