Results 131 to 140 of about 1,581 (179)

Positive Permanent Charge in Oxisols

Soil Science Society of America Journal, 1982
Abstract The existences of a positive permanent charge can be inferred from charge characteristics of highly weathered tropical soils; it was found to be related to isomorphous substitution of Ti(IV) for Fe(III) in iron oxides. Comparable near‐constant values were found from anion adsorption at pH 7.0 to 9.0.
Tessens, E., Zauyah, Siti
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57Fe Mössbauer studies of oxisols

Hyperfine Interactions, 1991
Mossbauer spectroscopy is a valuable complement to the standard analytical techniques of soil science for characterizing the iron content of soils, and for studying the mineralogical transformations that occur during pedogenesis from the point of view of the iron.
J. M. D. Coey, J. D. Fabris, Mauro Resende   +2 more
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Bivalent Ion Adsorption by an Oxisol

Soil Science Society of America Journal, 1989
Abstract Surface excesses of the bivalent ions Ca 2+ , Mg 2+ , and SO 2‐ 4 were measured on a Brazilian Oxisol suspended in Ca(ClO 4 )
Charlet, Laurent, Sposito, Garrison
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Phosphate Adsorption on an Oxisol

Soil Science Society of America Journal, 1977
Abstract Adsorption isotherms for phosphate on the A and B horizon of an oxisol from Papua New Guinea showed high affinity adsorption at low solution concentrations and a linear increase in adsorption at higher solution concentrations. Adsorption increased with decrease in pH in the range 3 to 8.
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Sorption of Paraquat on Clay Components in a Taiwan's Oxisol

Journal of Environmental Science and Health, Part B, 2003
The sorption of herbicides in soils is mainly influenced by clay components. The objectives of this study were to evaluate the contribution of clay components on paraquat sorption. The surface soils (0-20 cm) of a Laopi pedon (Fine, mixed, Hyperthermic Typic Hapludox) were separated clays into whole (< 2.0 microm), coarse (0.2-2.0 microm), and fine ...
Zeng-Yei, Hseu, Shih-Hao, Jien, Shuang-Fu, Cheng   +2 more
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Phosphate supplying power of rock phosphates in an oxisol

Plant and Soil, 1980
The P-supplying power of triple superphosphate, three apatitic rock phospates and a calcined aluminum rock phosphate were tested by measuring the quantities of fertilizer P recovered in soybean and in four chemical extractants, after 3-day and 75-day periods of contact between soil and fertilizer.
van Raij, B., van Diest, A.
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Magnetic properties of iron-rich oxisols

Physics and Chemistry of Minerals, 1988
Four occurrences of highly magnetic soil in Brazil have been analysed with a view to identifying the magnetic minerals and quantifying the soil magnetization. Techniques used include X-ray diffraction, X-ray fluorescence and Mossbauer spectroscopy. This approach leads us to identify several ways that these soils, which have spontaneous magnetization in
Jacqueline E. M. Allan, J. M. D. Coey, Mauro Resende, J. D. Fabris   +3 more
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Water fluxes in oxisols: A comparison of approaches

Water Resources Research, 1992
Two approaches to simulating soil water flow were evaluated: a capacity‐type water flow model combined with a plant water uptake model based on the concept of plant‐available water, and a numerical solution to the Richards equation combined with a potential‐driven water uptake model.
I. W. Buttler, S. J. Riha
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On the Measurement of Permanent Charge in Oxisols

Soil Science Society of America Journal, 1983
Abstract It is shown that the method used recently by Tessens and Zauyah to measure net permanent charge in Oxisols, based on a recommendation by Gillman and Uehara, can be justified theoretically without an appeal to diffuse double‐layer theory, or to any other detailed, molecular model of the interfacial region.
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Tree growth on a compacted Oxisol

Soil and Tillage Research, 1991
Abstract For a site at Barora, Solomon Islands, assessment was made of survival and growth of Gmelina arborea and Terminalia brassii planted on a heavy clay soil degraded by crawler tractor logging of primary forest and other processes. Experimental paired plots were established in 1981 on six classes of degraded soil and in undisturbed forest as a ...
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