Soil Textural Classification by a Photosedimentation Method (original) (raw)
Related papers
2019
There are global aspirations to harmonize soil particle size distribution data measured by the laser diffraction method and by traditional sedimentation techniques, e.g. sieve-pipette methods. The need has arisen therefore to build up a database, containing particle-size distribution values measured by the sieving and pipette method according to the Hungarian standard (sieve-pipette methods-MSZ) and the laser diffraction method according to a widespread and widely used procedure. In our current publication , 155 soil samples measured with sieve-pipette methods-MSZ and laser diffraction method (Malvern Mastersizer 2000, HydroG dispersion unit) were compared. Through the application of the usual size limits at the laser diffraction method, the clay fraction was under-and the silt fraction was overestimated compared to the sieve-pipette methods-MSZ results, and subsequently the soil texture classes were determined according to the results of both methods also differed significantly from each other. Based on our previous experience, the extension of the upper size limit of the clay fraction from 2 to 7 µm increases the comparability of sieve-pipette methods-MSZ and laser diffraction method, in this way the texture classes derived from the particle-size distributions were also more in accordance with each other. The difference between the results of the two kinds of particle-size distribution measurement methods could be further reduced with the pedotransfer functions presented.
A FAST METHOD FOR DETERMINING SOIL PARTICLE SIZE DISTRIBUTION USING A LASER INSTRUMENT
Soil Science, 2006
The sieve-pipette is the standard method for determining soil particle size distribution (PSD) because it is precise and reproducible. However, this method requires considerable time. Light diffraction methods for determining PSD are fast, but there is no standard procedure and often, results do not agree precisely with the pipette. The objective of this study was to develop a simple and fast procedure for sample handling and treatment of light diffraction method. A commercially available laserlight diffraction instrument was used. Soil samples were loaded dry into the instrument for ease and speed. A combination of chemical and physical dispersion within the instrument was found to be convenient and effective. Time required to analyze a sample was at most 15 min. Reproducibility between different operators was good, with S.E. ranging from 0.2% to 3.6%. Furthermore, we attempted to identify optimal values for the real refractive index and imaginary refractive index used in the optical model for light diffraction. Values of 1.42 and 0.001 for real refractive index and imaginary refractive index, respectively, were found to give acceptable results when compared with the pipette method. The light diffraction method was not significantly different from the pipette method for sand (P = 0.084), silt (P = 0.743), and clay (P = 0.052). Correlation between the light diffraction and pipette method for sand, silt, and clay was acceptable (R 2 = 0.88, 0.80, and 0.69, respectively). The light diffraction technique does not have a perfect agreement with the pipette method, but it provides data rapidly and was reproducible. This method can be very valuable when a large number of samples need to be analyzed for relative comparisons between different sites. (Soil Science 2006;171:663-674)
1990
This thesis has been submitted in partial fulfillment of requirements for an advanced degree at the University of Arizona and is deposited in the University Library to be made available to borrowers under the rules of the Library. Brief quotations from this thesis are allowable without special permission, provided that accurate acknowledgements of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his or her judgement the proposed use of the material is in the interest of scholarship. In all other instances, however, permission must be obtained from the author. SIGNED.
Soil Particle Size Analysis by Laser Diffractometry: Result Comparison with Pipette Method
IOP Conference Series: Materials Science and Engineering
Soil texture as the basic soil physical property provides a basic information on the soil grain size distribution as well as grain size fraction representation. Currently, there are several methods of particle dimension measurement available that are based on different physical principles. Pipette method based on the different sedimentation velocity of particles with different diameter is considered to be one of the standard methods of individual grain size fraction distribution determination. Following the technical advancement, optical methods such as laser diffraction can be also used nowadays for grain size distribution determination in the soil. According to the literature review of domestic as well as international sources related to this topic, it is obvious that the results obtained by laser diffractometry do not correspond with the results obtained by pipette method. The main aim of this paper was to analyse 132 samples of medium fine soil, taken from the Nitra River catchment in Slovakia, from depths of 15-20 cm and 40-45 cm, respectively, using laser analysers: ANALYSETTE 22 MicroTec plus (Fritsch GmbH) and Mastersizer 2000 (Malvern Instruments Ltd). The results obtained by laser diffractometry were compared with pipette method and the regression relationships using linear, exponential, power and polynomial trend were derived. Regressions with the three highest regression coefficients (R2) were further investigated. The fit with the highest tightness was observed for the polynomial regression. In view of the results obtained, we recommend using the estimate of the representation of the clay fraction (<0.01 mm) polynomial regression, to achieve a highest confidence value R2 at the depths of 15-20 cm 0.72 (Analysette 22 MicroTec plus) and 0.95 (Mastersizer 2000), from a depth of 40-45 cm 0.90 (Analysette 22 MicroTec plus) and 0.96 (Mastersizer 2000). Since the percentage representation of clayey particles (2nd fraction according to the methodology of Complex Soil Survey done in Slovakia) in soil is the determinant for soil type specification, we recommend using the derived relationships in soil science when the soil texture analysis is done according to laser diffractometry. The advantages of laser diffraction method comprise the short analysis time, usage of small sample amount, application for the various grain size fraction and soil type classification systems, and a wide range of determined fractions. Therefore, it is necessary to focus on this issue further to address the needs of soil science research and attempt to replace the standard pipette method with more progressive laser diffraction method.
Effect of Particle Optical Properties on Size Distribution of Soils Obtained by Laser Diffraction
Environmental and Engineering Geoscience, 2010
Particle size distribution (PSD) is essential information for those in the fields of engineering and environmental geosciences, sedimentology, and pedology. The PSD can be determined by conventional sieve, hydrometer, and pipette methods. However, since the 1980s, the PSD of soils has also been determined via the laser diffraction method, which is more reliable and faster and which can be used repeatedly. With this method there are two optical theories commonly used for the determination of PSD: the Mie and the Fraunhofer theories. The main difference between these theories is that the Mie theory requires the refractive index (RI) and absorption coefficient (AC) values of the particles and the RI value of the suspending medium, whereas the Fraunhofer theory does not. Although the Mie theory is more appropriate for soil samples, especially for the determination of clay-size fraction, there are not yet agreed-upon values of RI and AC for soils samples that can be used by researchers and practitioners. In this study, acceptable values for RI and AC were investigated extensively by analyzing 35 natural soil samples that were mainly of sedimentary origin. Based on the results obtained, the values of 1.55 and 0.1 for RI and AC, respectively, are suggested for laser diffraction analysis of naturally occurring sedimentary soil samples with respect to geotechnical practices. Furthermore, in order to demonstrate the pitfalls of using the Fraunhofer theory for the analysis of soil samples, especially for clay-size particles, the PSDs and clay-size fractions obtained from the Mie and Fraunhofer theories were also compared by setting different RI and AC values for the Mie theory.
Journal of Plant Nutrition and Soil Science, 2011
This paper presents the influence of selected methodological aspects on the results of particlesize distribution (PSD) as measured by the laser diffraction method (LDM). The investigations were carried out using the Mastersizer 2000 with Hydro MU attachment (Malvern Ltd., UK). It was found that for the investigated soils: (1) optimal speed of pump and stirrer was 2500 rpm, (2) optimal measurement time was ≈ 1 min, (3) there are two, practically equivalent methods for soil-sample dispersion: chemical (with the use of a solution of sodium hexametaphosphate) or physical (by means of ultrasound application for 4 min at a maximum power of 35W), (4) one must not use the chemical and physical dispersing methods simultaneously, because this can lead to aggregation (not dispersion) of soil particles, (5) the Fraunhofer theory (physical models) can be used to convert scattered-light data to PSD. In the case of the Mie theory, the best results were obtained for a refractive index (RI) in the range of 1.5-1.6 and an absorption index (AI) of 1.0. It was also found that most of the discussed parameters depend on design of the measuring device and on the type and volume of the investigated suspensions. It is necessary, therefore, to explain how the data was obtained every time and to specify the details in the methodological part of the paper.
Water
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%...
African Journal of Agricultural Research, 2012
The main objective of this study is to evaluate the ability of Visible Near-Infrared Reflectance Spectroscopy (VNIRS) to predict diverse soil properties in grinding different particular size effect. In this study, 60 soil samples were collected from the fields including different soil ordo (entisols, inceptisols, vertisols and mollisols) in Isparta (Atabey) district; crushed samples were subjected into five different mesh sizes (4.76 to 2.00, 2.00 to 1.00, 1.00 to 0.50, 0.5 to 0.25 and <0.25 mm, respectively). Each soil samples were scanned with a visible near-infrared spectrometer, with a spectral range of 350 to 2500 nm, at five different particular sizes. The spectral reflectances were used to predict some physical properties of the soil (texture, field capacity and wilting point) using partial least squares (PLS) regression. PLS analysis was used to develop calibration models between smoothed-first derivative 6nm-spaced spectral reflectance data and soil physical analysis measured clay, silt, sand, field capacity and wilting point. The results showed that while soils need to be crushed to pass through 0.25 mm sieve in order to determine wilting point and amount of clay, mesh size was found non-significant in determining sand, silt and field capacaity and the results obtained from the reflectance values taken from field samplings proved to be satisfactory.
SOIL TEXTURE ANALYSIS USING PARTICLE SIZE ANALYZER
Soil texture analysis was performed by using Laser Defreaction Particle Size Analyzer (LDPSA) in some soil samples of-Sungai Chalit, Raub, Pahang, Malaysia during August, 2017. The analysis was done in material technology laboratory of Malaysian Nuclear Agency. Depending on the locations of the collected samples, the particle sizes were found within the ranges 12.40-52.62%, 46.43-84.12% and 0.65-4.27% for sand, silt and clay, respectively. The analytical result shows that among the various particle sizes of the samples, silt and sand were present in major quantity, whereas clay in minor quantity. The particle size data were also fitted into the soil texture triangle and observed that out of five analyzed samples; three samples are grouped as silt loam, other two samples were grouped as silt only and sandy loam.