Laser Diffraction as An Innovative Alternative to Standard Pipette Method for Determination of Soil Texture Classes in Central Europe

Abstract

The paper presents the comparison of soil particle size distribution determined by standard pipette method and laser diffraction. Based on the obtained results (542 soil samples from 271 sites located in the Nitra, Váh and Hron River basins), regression models were calculated to convert the results of the particle size distribution by laser diffraction to pipette method. Considering one of the most common soil texture classification systems used in Slovakia (according to Novák), the emphasis was placed on the determination accuracy of particle size fraction <0.01 mm. Analysette22 MicroTec plus and Mastersizer2000 devices were used for laser diffraction. Polynomial regression model resulted in the best approximation of measurements by laser diffraction to values obtained by pipette method. In the case of particle size fraction <0.01 mm, the differences between the measured values by pipette method and both laser analyzers ranged in average from 3% up to 9% and from 2% up to 11% in the case of Analysette22 and Mastersizer2000, respectively. After correction, the differences decreased to average 3.28% (Analysette22) and 2.24% (Mastersizer2000) in comparison with pipette method. After recalculation of the data, laser diffraction can be used alongside the sedimentation methods.

Aggregate and Particle Size Distribution of the Soil Sediment Eroded on Steep Artificial Slopes

“…It was found that the fraction smaller than 2 µm obtained by the LD was lower compared to the sedimentation method, and the fraction smaller than 50 µm had an opposite result. This confirms the conclusions from the previous studies [21,23,[27][28][29][30][31] which state that the laser diffraction underestimates the clay fraction content and overestimates the silt fraction content. Furthermore, it was found that LD and hydrometer gave very similar results for particle size <10 µm.…”

“…In previous studies comparing particle size analysis methods based on different physical principles, it was found that the usability of the methods to obtain particle size distribution differ in the type of soil that is measured, mainly in the particle shape characteristics [23][24][25][26][27][28]. The studies where the sedimentation methods and laser diffraction were compared conclude that the volume representation of the clay fraction obtained by laser diffraction was generally lower than the mass representation of the clay fraction derived by the pipette or hydrometer method, while an opposite trend was determined for the silt fraction [21,23,[27][28][29][30][31]. Conclusions from the study of comparison of laser diffractometer and sieving method are that the sieving method underestimates particles which contain non-equant grain types compared to the laser diffraction, because grains with a width to length ratio of 0.5 can pass through smaller mesh size of the sieve [31].…”

The Evaluation of the Accuracy of Interpolation Methods in Crafting Maps of Physical and Hydro-Physical Soil Properties

“…Agricultural land accounts for 69% of the river basin area. Forests cover 1430 km 2 of the basin, of which 892 km 2 are located in the upper part of the basin [17,40]. In terms of grain size distribution, light soils 3.7%, medium heavy soils, 77.9%, heavy soils 13.6% and very heavy soils 4.8% can be found in the Nitra River Basin [41].…”

“…At present, there are several options and methodological procedures for the processing, treatment and subsequent web distribution of soil properties in the format of a map output. The soil properties are mostly determined on the basis of field sampling using soil pits and augers and the subsequent laboratory analyzes [17,18]. The accumulated data are tied to a sampling point, determined by the spatial coordinates (X, Y, Z).…”

Hydrological Impacts of Climate Change and Land Use

“…The possibility of surface water and groundwater reduction could also affect the availability of water resources in the catchment and further aggravate water stress in the downstream [6]. Some papers in the SI were focused on the impact of climate change on the change of groundwater regime [7] and subsequently on the change of hydrological properties of soils [8]. The authors [9] confirmed in the regions of Central Europe as well as in the Netherlands [10] significant shifts in runoff seasonality, coinciding with the timing of the air temperature rise, marked by earlier snow-melt, followed by a decline in spring flows and a prolonged period of low flows.…”