scholarly journals Use of class pedotransfer functions based on texture and bulk density of clods to generate water retention curves

2003 ◽  
Vol 19 (3) ◽  
pp. 232-242 ◽  
Author(s):  
A. Bruand ◽  
P. Perez Fernandez ◽  
O. Duval
Keyword(s):  
Bulk Density ◽  
Water Retention ◽  
Pedotransfer Functions

scholarly journals Evaluation of Water Retention Curves by Regression and Machine Learning Methods

2021 ◽  
Vol 1203 (3) ◽  
pp. 032088
Author(s):  
Milan Cisty ◽  
Barbora Povazanova
Keyword(s):  
Bulk Density ◽  
Water Retention ◽  
Pedotransfer Functions ◽  
Water Retention Curve ◽  
Support Vector ◽  
Data Set ◽  
Retention Curve ◽  
Vector Machines ◽  
The One

Abstract The paper presents two methods that simplify the estimation of the water retention curves. The case study is evaluated for the soils of Záhorská lowland in the paper. These methods are based on the supposed dependence of the soil water content on the percentage content of the 1st, 2nd, 3rd and 4th Kopecký grain categories, and the dry bulk density. The representative set of the drying branch of water retention curves was measured using soil samples from the Záhorská lowland region in a laboratory. Particle size distribution and dry bulk density were also determined. In this paper support vector machines and multiple linear regression is compared to estimate the pedotransfer functions that can be used for the prediction of the drying branch of the water retention curve. Both methods were verified on other data set of measured water retention curves than the one which was used for building the models with a close agreement to measured results.

Development of class pedotransfer functions for integrating water retention properties into Portuguese soil maps

Soil Research ◽  
2013 ◽  
Vol 51 (4) ◽  
pp. 262 ◽  
Author(s):  
T. B. Ramos ◽  
M. C. Gonçalves ◽  
D. Brito ◽  
J. C. Martins ◽  
L. S. Pereira
Keyword(s):  
Water Balance ◽  
Bulk Density ◽  
Water Retention ◽  
Swat Model ◽  
Pedotransfer Functions ◽  
Soil Horizon ◽  
Soil Maps ◽  
Catchment Scale ◽  
Small Catchment ◽  
Water Retention Properties

Hydrological modellers have recently been challenged to improve watershed models by better integrating soil information into model applications. Reliable soil hydraulic information is thus necessary for better describing the water balance components at the catchment scale. Frequently, that information does not exist. This study presents a set of class-pedotransfer functions (PTFs) for estimating the water retention properties of Portuguese soils. The class-PTFs were established from a dataset containing 697 soil horizons/layers, by averaging values of total porosity and volumetric water contents at –0.25, –1, –3.2, –6.3, –10, –33, –100, –250, and –1500 kPa matric potentials after grouping data by soil texture class, soil horizon, and bulk density. Fitted retention curves using the van Genuchten model were also obtained for every class-PTF. The root mean square error varied between 0.039 and 0.057 cm3/cm3, with smaller values found when using the 12 texture classes of the International Soil Science Society (ISSS) system rather than the five texture classes of FAO, and when bulk density was also considered. The class-PTFs were then integrated into Portuguese soil maps and its usage was demonstrated by deriving maps of available water capacity to be used for modelling the water balance in a small catchment area with the SWAT model. The model successfully simulated the reservoir inflow when using the derived maps, but the results did not vary much whether using coarser or finer description of the catchment soils. Nonetheless, the class-PTFs contributed to a better soil characterisation than when using coarse-scaled information. The approach followed here was simple, inexpensive, and feasible for modellers with few resources but interested in considering the spatial variability of soil retention properties at large scales and in advancing hydrologic modelling in Portugal.

Deriving point and parametric pedotransfer functions of some gypsiferous soils

Soil Research ◽  
2008 ◽  
Vol 46 (3) ◽  
pp. 219 ◽  
Author(s):  
Mehdi Homaee ◽  
Ahmad Farrokhian Firouzi
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Bulk Density ◽  
Size Distribution ◽  
Water Retention ◽  
Pedotransfer Functions ◽  
Water Retention Curve ◽  
Geometric Standard Deviation ◽  
Retention Curve ◽  
Gypsum Content

Parametric description of the soil water retention curve as well as the hydraulic conductivity curve is needed for modelling water movement and solute transport in the vadose zone. The objective of this study was to derive pedotransfer functions (PTFs) to predict the water retention curve and the van Genuchten and the van Genuchten–Mualem parameters of some gypsiferous soils. Consequently, 185 gypsiferous soil samples were collected and their physical properties were measured. The particle size distribution was determined in 2 steps: (i) with gypsum, by covering the particles with barium sulphate; (ii) without gypsum, using the hydrometry method. The easily obtainable variables were grouped as (1) particle size distribution, bulk density, and gypsum content; and (2) bulk density, gypsum content, geometric mean, and geometric standard deviation of the particle diameter. Stepwise multiple linear regression method was used to derive the PTFs. Two types of parametric and point functions were derived using these variables. The first group of variables predicted water retention and the van Genuchten and van Genuchten–Mualem parameters better than the second group. The gypsum content appeared to be the second dominant parameter for predicting water retention at 0, −330, −1000, −3000, −5000, and −15 000 cm. The derived PTFs were compared with the Rosetta database as independent dataset. The validity test indicated that in order to predict the hydraulic properties of gypsiferous soils the derived PTFs are more accurate than what can be obtained from the Rosetta database. Removal of gypsum increased the water retention at pressure heads of 0, –100, –330, –1000, –3000, –5000, and –15 000 cm (P < 0.01). The results also indicated that hydraulic parameters were different for the same soil with and without gypsum.

New pedotransfer functions for soil water retention curves that better account for bulk density effects

2021 ◽  
Vol 205 ◽  
pp. 104812
Author(s):  
Zhengchao Tian ◽  
Jiazhou Chen ◽  
Chongfa Cai ◽  
Weida Gao ◽  
Tusheng Ren ◽  
...  
Keyword(s):  
Bulk Density ◽  
Soil Water ◽  
Water Retention ◽  
Pedotransfer Functions ◽  
Soil Water Retention ◽  
Density Effects

Evaluation of soil pedotransfer functions for soils of the Csallóköz and Szigetköz regions

2003 ◽  
Vol 51 (3) ◽  
pp. 355-367 ◽  
Author(s):  
V. Štekauerová ◽  
J. Šútor ◽  
C. Farkas
Keyword(s):  
Particle Size ◽  
Bulk Density ◽  
Soil Water ◽  
Water Retention ◽  
Laboratory Method ◽  
Pedotransfer Functions ◽  
Soil Water Retention ◽  
Statistical Relationships ◽  
Measured Water ◽  
Good Agreement

In this study pedotransfer functions (PTFs) were developed to estimate the soil water retention curves (SWRCs) for Rye Island (Csallóköz, S. W. Slovakia). A representative set of soil water retention curves was measured using a laboratory method on samples taken from soils the study area. Particle size distribution and bulk density were determined as well. Multiple regression analysis was used for estimating nine statistical relationships in order to predict the drying part of the SWRCs. Texture and bulk density were used as predictors. Pedotransfer functions were verified on another set of measured water retention curves from the same territory as well as on SWRCs determined for soils of the Szigetköz region in Hungary. A good agreement was found between the calculated and measured SWRCs for the Slovakian soils, while somewhat poorer estimates could be given for Hungarian soils.

A generally applicable pedotransfer function that estimates field capacity and permanent wilting point from soil texture and bulk density

2008 ◽  
Vol 88 (5) ◽  
pp. 761-774 ◽  
Author(s):  
J. A. P. Pollacco
Keyword(s):  
Organic Matter ◽  
Soil Moisture ◽  
Bulk Density ◽  
Soil Texture ◽  
The United States ◽  
Pedotransfer Functions ◽  
Pedotransfer Function ◽  
Data Set ◽  
Wide Range ◽  
Fitting Parameters

Hydrological models require the determination of fitting parameters that are tedious and time consuming to acquire. A rapid alternative method of estimating the fitting parameters is to use pedotransfer functions. This paper proposes a reliable method to estimate soil moisture at -33 and -1500 kPa from soil texture and bulk density. This method reduces the saturated moisture content by multiplying it with two non-linear functions depending on sand and clay contents. The novel pedotransfer function has no restrictions on the range of the texture predictors and gives reasonable predictions for soils with bulk density that varies from 0.25 to 2.16 g cm-3. These pedotransfer functions require only five parameters for each pressure head. It is generally accepted that the introduction of organic matter as a predictor improves the outcomes; however it was found by using a porosity based pedotransfer model, using organic matter as a predictor only modestly improves the accuracy. The model was developed employing 18 559 samples from the IGBP-DIS soil data set for pedotransfer function development (Data and Information System of the International Geosphere Biosphere Programme) database that embodies all major soils across the United States of America. The function is reliable and performs well for a wide range of soils occurring in very dry to very wet climates. Climatical grouping of the IGBP-DIS soils was proposed (aquic, tropical, cryic, aridic), but the results show that only tropical soils require specific grouping. Among many other different non-climatical soil groups tested, only humic and vitric soils were found to require specific grouping. The reliability of the pedotransfer function was further demonstrated with an independent database from Northern Italy having heterogeneous soils, and was found to be comparable or better than the accuracy of other pedotransfer functions found in the literature. Key words: Pedotransfer functions, soil moisture, soil texture, bulk density, organic matter, grouping

scholarly journals Assessment of pedotransfer functions for estimating soil water retention curves for the amazon region

2014 ◽  
Vol 38 (3) ◽  
pp. 730-743 ◽  
Author(s):  
João Carlos Medeiros ◽  
Miguel Cooper ◽  
Jaqueline Dalla Rosa ◽  
Michel Grimaldi ◽  
Yves Coquet
Keyword(s):  
Soil Water ◽  
Water Retention ◽  
Soil Layer ◽  
Direct Determination ◽  
Exchange Capacity ◽  
Pedotransfer Functions ◽  
Water Retention Curve ◽  
Spatial And Temporal Variability ◽  
Soil Water Retention Curve ◽  
Soil Water Retention

Knowledge of the soil water retention curve (SWRC) is essential for understanding and modeling hydraulic processes in the soil. However, direct determination of the SWRC is time consuming and costly. In addition, it requires a large number of samples, due to the high spatial and temporal variability of soil hydraulic properties. An alternative is the use of models, called pedotransfer functions (PTFs), which estimate the SWRC from easy-to-measure properties. The aim of this paper was to test the accuracy of 16 point or parametric PTFs reported in the literature on different soils from the south and southeast of the State of Pará, Brazil. The PTFs tested were proposed by Pidgeon (1972), Lal (1979), Aina & Periaswamy (1985), Arruda et al. (1987), Dijkerman (1988), Vereecken et al. (1989), Batjes (1996), van den Berg et al. (1997), Tomasella et al. (2000), Hodnett & Tomasella (2002), Oliveira et al. (2002), and Barros (2010). We used a database that includes soil texture (sand, silt, and clay), bulk density, soil organic carbon, soil pH, cation exchange capacity, and the SWRC. Most of the PTFs tested did not show good performance in estimating the SWRC. The parametric PTFs, however, performed better than the point PTFs in assessing the SWRC in the tested region. Among the parametric PTFs, those proposed by Tomasella et al. (2000) achieved the best accuracy in estimating the empirical parameters of the van Genuchten (1980) model, especially when tested in the top soil layer.

Multiscale Pedotransfer Functions for Soil Water Retention

2007 ◽  
Vol 6 (4) ◽  
pp. 868-878 ◽  
Author(s):  
Raghavendra B. Jana ◽  
Binayak P. Mohanty ◽  
Everett P. Springer
Keyword(s):  
Soil Water ◽  
Water Retention ◽  
Pedotransfer Functions ◽  
Soil Water Retention

The effects of biochar on soil physical properties and winter wheat growth

2012 ◽  
Vol 103 (1) ◽  
pp. 13-18 ◽  
Author(s):  
Rachel C. Devereux ◽  
Craig J. Sturrock ◽  
Sacha J. Mooney
Keyword(s):  
Pore Size ◽  
Bulk Density ◽  
Water Retention ◽  
Average Pore Size ◽  
Water Repellency ◽  
Soil Bulk Density ◽  
Average Pore ◽  
Wheat Growth ◽  
Wetting Ability ◽  
X Ray Computed

ABSTRACTBiochar has been reported to improve soil quality and crop yield; however, less is known about its effects on the physical and, in particular, structural properties of soil. This study examines the potential ability of biochar to improve water retention and crop growth through a pot trial using biochar concentrations of 0%, 1·5%, 2·5% and 5% w/w. X-ray computed tomography was used to measure soil structure via pore size characteristics; this showed that pore size is significantly affected by biochar concentration. Increasing biochar is associated with decreasing average pore size, which we hypothesise would impact heavily on hydraulic performance. At the end of the experiment, average pore size had decreased from 0·07 mm2 in the 0% biochar soil to 0·046 mm2 in the 5% biochar soil. Increased biochar concentration also significantly decreases saturated hydraulic conductivity and soil bulk density. It was also observed that increased biochar significantly decreases soil water repellency. Increased water retention was also observed at low matric potentials, where it was shown that increased biochar is able to retain more water as the soil dried out. The application of biochar had little effect on short-term (<10 weeks) wheat growth, but did improve water retention through a change in soil porosity, pore size, bulk density and wetting ability.

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