Determination of soil texture: Comparison of the sedimentation method and the laser‐diffraction analysis

Abstract

Laser-diffraction analysis (LDA) is a rapid automated method achieving highly resolved frequency distributions of particle sizes. Recently, LDA has come into use in environmental sciences. However, in the size range of silt and clay deviations from the particle-size analysis with the standard pipette method, which is regarded as the reference method for soil-texture classification, have been reported. Therefore, this study concentrates (1) on the verification of systematic relations between both methods using a series of soils of Lower Saxony (Germany) and (2) on the general applicability of the laser-diffraction method to soil-texture classification as well as (3) texture-based estimates of air capacity, available field capacity, and permanent wilting point. The comparison of LDA with the pipette method demonstrated highly significant linear correlations in each of the particle-size fractions from clay to coarse silt. The slope of regressions ranged from 0.4 with fine silt to 3.1 with clay. If the clay content derived from LDA was applied to texture classification, the resulting textural classes differed from the standard textural classes, except for purely sandy samples with a clay content of <5%. However, the linear-regression model enabled an approach of the LDA-based clay content to values produced with the standard pipette method. Using this transformation, a texture classification became practicable in many cases, but, despite of a high significance level between LDA and pipette method, still led to wrong textural classes in several cases. A comparison with regression models from other regions in Europe showed both similarities and discrepancies, even for similar substrates. Hence, the laser-diffraction analysis cannot be used for the texture classification of soil samples without verification by the standard pipette method.

Drought Decreases Growth and Increases Mortality of Coexisting Native and Introduced Tree Species in a Temperate Floodplain Forest

“…The C and N concentrations, the texture (sand and loam percentages), the pH, and the electrical conductivity of soil samples were also assessed to test if they differ between living and dead trees. Soil texture was determined with the laser diffraction method in a Coulter Mastersizer 2000 and clay content was corrected [61]. Soil C and N concentrations and the C/N ratio were determined with an elemental analyzer (Elementar VarioMAX N/CM, Hanau, Germany).…”

Microscope-based computer vision to characterize soil texture and soil organic matter

“…All these methods require sophisticated equipments that are very expensive and needs regular maintenance. Additionally, these methods often show inconsistent results for heterogeneous soil samples as compared to homogenous materials such as quartz or glass beads that are used to calibrate the equipments (Taubner, Roth, & Tippk€ otter, 2009). Other technique such as visible-near infrared (Vis-NIR) spectroscopy suffers from the necessary depth of resolution in measurements.…”

Laser-induced breakdown spectroscopy to determine soil texture: A fast analytical technique

“…Prior to analysis, however, all these methods also require a preprocessing step to disperse the aggregates, which usually takes a full day. Furthermore, these methods do not have proper correspondence with the pipette or hydrometer for determining the size of the smallest particles, clay and silt (Taubner et al, 2009). Soil texture can also be indirectly determined by visible or infrared reflectance spectroscopy (e.g., Chang et al, 2001;Madari et al, 2006;Rossel et al, 2006;Curcio et al, 2013).…”