Full soil particle size fingerprints determined by laser diffraction of 48 selected test samples from Flanders (Belgium)

A set of 48 soil test samples was selected for a study (1) comparing two common methods for granulometric analysis: pipette-sieving method versus laser diffractometry (LD), (2) comparing the results among various LD instruments and (3) analysing the effect size of various settings on LD instruments (e.g. effect of diffraction models & optical parameters). All 48 samples originated from soils of Flanders (North of Belgium) and were taken in 4 landuses (croplands (n=8), grasslands (n=18), gardens (n=13) and natural habitats (n=9)) on the most common soil types and textures. The samples widely varied in organic carbon content and pH. The datasets are the output of the full soil textural ‘fingerprint’ (particle size range from 0,4 - 2000 µm) of the test samples analysed by a Beckman COULTER LS13320 laser diffraction instrument. Pretreatment of the soil samples was conducted according to ISO 11464 and the removal of organic matter and carbonates was done according to ISO 11272 as for the Sieving and Sedimentation method. Background information is given in the presentation (PDF): “Should laser diffraction become the new standard for soil particle size analysis ?” The equivalent LD diameters applied to convert the pipette based standard limits for clay fraction (2 µm) were set to 6 µm when using LD particle sizes and for silt (50 µm) to 63 µm (LD size). For each test sample the full textural fingerprint is given according to size bins showing for each bin the mean fraction (in vol%) of 5 replicated measurements along with the standard deviation (sd) under repeatability conditions. Based on the full fingerprint various fractions can be derived and statistically compared. The full fingerprint is also useful for calibrating pedotransfer functions for estimating other soil physical properties and for in silico modeling purposes.