ISO 11272:2017 - Soil quality - Determination of dry bulk density
Overview
ISO 11272:2017 specifies standardized laboratory and field procedures to determine the dry bulk density of soils. The standard defines three primary methods - the core method, excavation (sand replacement) method, and clod method - all based on measuring the oven‑dry mass of a soil sample and the sample volume. Dry bulk density is a fundamental soil property used to calculate solids content, porosity and to convert concentrations between mass/volume and mass/mass.
Key technical topics and requirements
- Three accepted methods
- Core method: For stoneless or slightly stony soils. Thin‑walled metal core samplers (100–400 cm3) are used; samples are dried at (105 ± 2) °C to constant mass. Take at least six cores per soil layer where representative data are required.
- Excavation (sand replacement) method: For soils with gravel or stones. Excavated volume is determined by filling the hole with dry graded sand (particle size 500–700 µm) using a funnel (5 cm falling height) and measuring displaced sand volume.
- Clod method: Uses coated or stabilized clods to determine volume; included as a laboratory alternative where core sampling is impractical.
- Apparatus and accuracy: Specifies ovens, desiccators and balances (core method balance accuracy to 1/1 000 of the measured value; excavation method balance accuracy 0.1 g). Sieving, sand grading and cleaning procedures are described where applicable.
- Moisture control and drying: Samples must be oven dried to constant mass and cooled in a desiccator; procedures address swell/shrink soils (clays, peats) and combined water‑content measurements.
- Calculations and reporting: Dry bulk density is calculated as oven‑dry mass divided by sample volume. The standard also details the information to include in the test report and includes annexes (e.g., use of plastic balls for volume determination and water density vs. temperature).
Practical applications and typical users
- Environmental consultants and soil scientists assessing soil structure, compaction, porosity and contaminant mass balances.
- Agronomists and land managers evaluating tillage effects, root zone density and crop‑growth constraints.
- Geotechnical and civil engineers needing in‑situ density values for foundation and earthworks design.
- Accredited testing laboratories performing routine soil characterization and regulatory compliance testing.
Related standards and references
- ISO 11508 (particle density) - used with dry bulk density to compute porosity and solids content.
- Normative references cited in ISO 11272: ASTM D1556, ASTM D2167, ASTM D4914, ASTM D5030, DIN 18125‑2.
- Annexes in ISO 11272 provide practical alternatives (plastic balls) and temperature correction data for water density.
Keywords: ISO 11272:2017, dry bulk density, soil quality, core method, excavation method, clod method, soil sampling, bulk density determination, soil porosity, soil testing.
