Overview
EN ISO 11274:2019 - Soil quality: Determination of the water‑retention characteristic - Laboratory methods (ISO 11274:2019) specifies laboratory procedures to measure the soil water‑retention characteristic for the drying (desorption) curve. Prepared under CEN/ISO, the standard defines methods, apparatus and reporting rules to determine the relationship between soil water content and matric pressure (suction) across the full practical range used in soil science and environmental assessment.
Key topics
- Scope and limitations
- Applies only to the drying/desorption curve (not the wetting curve).
- Covers laboratory measurements of matric pressures from near 0 kPa down to very negative pressures.
- Four laboratory methods (selected by pressure range and sample type):
- Sand, kaolin or ceramic suction tables: 0 kPa to −50 kPa.
- Porous plate and burette apparatus: 0 kPa to −20 kPa.
- Pressure plate extractor: −5 kPa to −1 500 kPa.
- Pressure membrane cells: −33 kPa to −1 500 kPa.
- Guidance for method selection - criteria to choose the most appropriate method for soil texture, sample size and target pressure range.
- Sampling and sample preparation - general requirements to obtain representative laboratory samples and prepare them for testing.
- Detailed procedures and apparatus - step‑by‑step descriptions for assembly, operation, equilibration and measurement for each method.
- Data expression and reporting - conversion to fine‑soil basis where applicable, calculations, precision and required test report contents.
Applications
EN ISO 11274:2019 is practical for:
- Soil scientists and research laboratories establishing the water‑retention curve for different soil types.
- Agronomists and irrigation planners estimating plant‑available water and irrigation scheduling.
- Hydrologists and modelers using water‑retention data for vadose‑zone and drainage modeling.
- Environmental consultants and geotechnical engineers assessing drainable porosity, contaminant transport potential and slope/soil stability.
- Regulatory or certification labs requiring standardized, reproducible soil water‑retention measurements for comparison across sites and time.
By standardizing the laboratory methods (suction tables, porous plates, pressure plate extractors and membrane cells) and specifying how to express results, EN ISO 11274:2019 supports consistent, comparable water‑retention data for applied research, design and regulatory use.
Related standards
This document was prepared by ISO/TC 190 (Soil quality). For comprehensive soil characterization, EN ISO 11274:2019 is typically used alongside other ISO/CEN soil quality standards covering sampling, physical and chemical test methods and reporting requirements.
