Physical and Mineralogical Data to Determine Soil Hydraulic Properties

Abstract

A study was conducted to determine relationships among physical, mineralogical, and soil hydraulic properties of Ultisols developed in unconsolidated sediments of the Lower Coastal Plain. Soil water retention curves, saturated hydraulic conductivity, bulk density, quantitative mineralogy, surface area, and particle size distribution were determined by horizon for seven pedons and relationships among them were analyzed by regression analysis procedures. Fine sand, sand and clay percentages were highly correlated with saturated hydraulic conductivity, surface area and volumetric water contents at specific pressure heads. Correlation coefficients > 0.95 were obtained for regression equations estimating soil water retention curves from particle size data. These relationships can be useful for quick characterization of soil hydraulic properties from particle size distribution data. No significant correlations were found between soil hydraulic and mineralogical properties of the clay fraction.

Comparison of three methods of measuring surface area of soils

“…The percent W20 and percent W47 were also excellent predictors of CEC and water retained at 1.5 MPa. The surface areas measured by the EGME, N 2 and H 2 O sorption methods generally do not indicate the soils ability to transmit water or gases (Puckett et al 1985;Petersen et al 1996), but hopefully will indicate the sorbing power of the soil for constituents in these fluids. SA EGME is believed to represent the total SA of the soil minerals, but it is not clear if it includes the contribution of the amorphous substances.…”

“…Water retention (Puckett et al 1985;Petersen et al 1996), shrink-swell properties (Ross 1978;de Jong et al 1992) and sorption of organic and inorganic substances (Greenland 1965;Scheidegger and Sparks 1996) in soils are affected by the extent and nature of the solid surfaces. Surface area is related to clay content and type, but the contribution of amorphous organic (Pennell et al 1995) and mineral compounds to the surface area of soils is not clear.…”

Estimation of water retention and availability in soils of Rio Grande do Sul

“…Baumer & Brasher (1982) considered the effect of mineralogy in studies of soil water retention as an important variable. In a study by Puckett et al (1985) in soils with similar mineralogy, the variables particle size distribution, bulk density and porosity were adequate to estimate water retention, while in soils with great mineralogical variation Hodnett & Tomasella (2002) affirmed that mineralogy is a variable that significantly influences soil water retention and, when available, must be considered in the generation of pedotransfer functions.…”

Estimating Hydraulic Conductivity Using Pedotransfer Functions

“…Two of these methods also estimate bulk density. Soilpar 2 uses PTFs of Jabro (1992), Jaynes and Tyler (1984), Puckett et al (1985), andCampbell (1985) to estimate saturated hydraulic conductivity. Function PTFs, which estimate the parameters of retention functions are implemented: Rawls and Brakensiek (1989), to estimate the Brooks and Corey (1964) function parameters; Vereecken et al (1989), to estimate the van Genuchten (1980) function parameters; Campbell (1985) to estimate the Campbell function parameters (Campbell, 1974)); Mayr and Jarvis (1999), to estimate the parameters of the Hutson and Cass (1987) modification of the Campbell function.…”