Predicting soil nonaqueous phase liquid retention with pedotransfer functions

2014 ◽  
Vol 63 (1) ◽  
pp. 9-18
Author(s):  
Hilda Hernádi ◽  
A. Makó
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Organic Matter Content ◽  
Matter Content ◽  
Pedotransfer Functions ◽  
Soil Parameters ◽  
Retention Data ◽  
Independent Variables ◽  
Liquid Retention

The obtained results of the present study showed the good applicability of the van Genuchten equation for parameterizing NAPL retention data of soils (R2 = 0.99).Sufficient applicability of continuous PTFs for estimating the parameters of NAPL retention curves was found (R2 for α, n and θs was 0.47, 0.84 and 0.86, respectively).The accuracy of parametric and point PTFs increased in case derived values of the independent variables in addition to the PSD (particle size distribution) fractions, bulk density, CaCO3 and organic matter content (R2 = 0.57–0.90 and RMSE = 2.43–5.67 vol%) were used, as compared to PTFs using only the original values of basic soil parameters as predictor variables (R2 = 0,48–0.86; RMSE = 3.56–6.83 vol%).According to the gained results, PTFs seem to be similarly accurate if the particle size distribution of soils — determined by different standard methods — are applied as independent variables.

Evaluating the Integral Suspension Pressure method for measuring the particle size distribution in soils with high organic matter content

2020 ◽  
Author(s):  
Cristina Contreras ◽  
Sara Acevedo ◽  
Sofía Martínez ◽  
Carlos Bonilla
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Soil Analysis ◽  
Organic Matter Content ◽  
Matter Content ◽  
New Methodologies ◽  
Pre Treatment ◽  
Standard Techniques

<p>Typical information in soil databases is the soil texture and particle size distribution. These properties are used for soil description or predicting other soil properties such as bulk density or hydraulic conductivity. Measuring particle size distribution with standards methods such as the pipette or hydrometer is time-consuming because of the sample pre-treatment used to remove organic matter or iron and the sample post-treatment. Nowadays, there are new methodologies for determining soil particle size distribution, such as the Integral Suspension Pressure (ISP) method, which measures the silt content in a semi-automatized process. Thus, the main objective of this study was to evaluate the suitability of the ISP method compared to standard techniques used in soil analysis and evaluate the effect of organic matter content in the ISP measurements. The main results showed that the ISP method is equivalent in accuracy to the pipette, especially for soils rich in silt or sand content. Also, the results demonstrate the convenience of removing the soil organic matter when using the ISP for soils with more than 1.5% organic matter.</p>

WITHIN-PEDON VARIABILITY IN SOIL PROPERTIES

1982 ◽  
Vol 62 (4) ◽  
pp. 631-639 ◽  
Author(s):  
G. T. PATTERSON ◽  
G. J. WALL
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Calcium Carbonate ◽  
Particle Size Distribution ◽  
Soil Properties ◽  
Size Distribution ◽  
Organic Matter Content ◽  
Matter Content ◽  
Soil Drainage ◽  
Soil Material

Replicate soil samples (2–20) from the A, B and C horizons of 41 pedons were collected to measure within-pedon variability of particle size distribution, organic matter content, calcium carbonate equivalent and pH. Variability in soil properties was examined in relation to the mode of origin of the soil material, soil horizonation and soil drainage. Variance in particle size distribution was significantly influenced by mode of deposition as well as by soil horizons, while soil drainage had no significant influence on the variation in particle size distribution. Variance in calcium carbonate equivalent and organic matter content was not influenced by soil drainage or mode of deposition. The number of replicate samples required for statistically reliable evaluation of a pedon at given confidence limits was determined for the soil properties studied. The results of these calculations indicate the need for up to five replicate samples to achieve satisfactory levels of accuracy at the 95% confidence level for some of the soil properties studied.

scholarly journals Pedotransfer functions to estimate water retention parameters of soils in northeastern Brazil

2013 ◽  
Vol 37 (2) ◽  
pp. 379-391 ◽  
Author(s):  
Alexandre Hugo Cezar Barros ◽  
Quirijn de Jong van Lier ◽  
Aline de Holanda Nunes Maia ◽  
Fábio Vale Scarpare
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Particle Size Distribution ◽  
Water Content ◽  
Size Distribution ◽  
Water Retention ◽  
Northeastern Brazil ◽  
Pedotransfer Functions ◽  
Residual Water ◽  
Specific Pressure

Pedotransfer functions (PTF) were developed to estimate the parameters (α, n, θr and θs) of the van Genuchten model (1980) to describe soil water retention curves. The data came from various sources, mainly from studies conducted by universities in Northeast Brazil, by the Brazilian Agricultural Research Corporation (Embrapa) and by a corporation for the development of the São Francisco and Parnaíba river basins (Codevasf), totaling 786 retention curves, which were divided into two data sets: 85 % for the development of PTFs, and 15 % for testing and validation, considered independent data. Aside from the development of general PTFs for all soils together, specific PTFs were developed for the soil classes Ultisols, Oxisols, Entisols, and Alfisols by multiple regression techniques, using a stepwise procedure (forward and backward) to select the best predictors. Two types of PTFs were developed: the first included all predictors (soil density, proportions of sand, silt, clay, and organic matter), and the second only the proportions of sand, silt and clay. The evaluation of adequacy of the PTFs was based on the correlation coefficient (R) and Willmott index (d). To evaluate the PTF for the moisture content at specific pressure heads, we used the root mean square error (RMSE). The PTF-predicted retention curve is relatively poor, except for the residual water content. The inclusion of organic matter as a PTF predictor improved the prediction of parameter a of van Genuchten. The performance of soil-class-specific PTFs was not better than of the general PTF. Except for the water content of saturated soil estimated by particle size distribution, the tested models for water content prediction at specific pressure heads proved satisfactory. Predictions of water content at pressure heads more negative than -0.6 m, using a PTF considering particle size distribution, are only slightly lower than those obtained by PTFs including bulk density and organic matter content.

scholarly journals Particle Size Distribution of Natural Clayey Soils: A Discussion on the Use of Laser Diffraction Analysis (LDA)

Geosciences ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 55
Author(s):  
Aleksandra Gorączko ◽  
Szymon Topoliński
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Diffraction Analysis ◽  
Size Distribution ◽  
Clay Fraction ◽  
Laser Diffraction ◽  
Pedotransfer Functions ◽  
Clayey Soils ◽  
Selection Of

Particle size distribution is one of the most significant factors determining physical soil properties. Laser diffraction analysis (LDA) is an alternative method to the traditional hydrometric methods (HM) used to determine particle size distribution in soils. However, significant differences in fraction content are found in relation to the applied methods of a particle size test. Above all, measurements performed by LDA for clayey soils usually produce different results to those based on Stokes’ equation. Methodical problems, such as an appropriate method of dispersing the sample and the selection of LDA calculation theory, also play a significant role in fine soils. This paper contains the results of analyses of Neogene clays from Poland, which are characterized by differentiation with regard to the content of clay fraction particles. In this article, the validity of using laser diffraction analysis (LDA) for the identification and characterization of clayey sediments with common genesis is assessed. The possibility of finding reliable pedotransfer functions to the convert LDA results to a hydrometric analysis is discussed.

Relationships between field texture and particle-size distribution in Australia and their implications

Soil Research ◽  
2007 ◽  
Vol 45 (6) ◽  
pp. 428 ◽  
Author(s):  
Budiman Minasny ◽  
Alex B. McBratney ◽  
Damien J. Field ◽  
Grant Tranter ◽  
Neil J. McKenzie ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Classification System ◽  
Soil Classification ◽  
Particle Size Analysis ◽  
Pedotransfer Functions ◽  
Size Analysis ◽  
Texture Contrast ◽  
Australian Soil

This paper aims to establish the means and ranges of clay, silt, and sand contents from field texture classes, and to investigate the differences in the field texture classes and texture determined from particle-size analysis. The results of this paper have 2 practical applications: (1) to estimate the particle size distribution and its uncertainty from field texture as input to pedotransfer functions, and (2) to examine the criteria of texture contrast soils in the Australian Soil Classification system. Estimates of clay, silt, and sand content for each field texture class are given and this allows the field texture classes to be plotted in the texture triangle. There are considerable differences between field texture classes and particle-size classes. Based on the uncertainties in determining the clay content from field texture, we establish the probability of the occurrence of a texture contrast soil according to the Australian Soil Classification system, given the texture of the B2 horizon and its overlying A horizon. I enjoy doing the soil-texture feel test with my fingers or kneading a clay soil, which is a short step from ceramics or sculpture. Hans Jenny (1984)

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