Colloidal Properties of Some Florida Soils
1958
Fiskell, J. G. A. | Gammon, N. | Yuan, T. L. | Zmeskal, O.
The relationships between the mineralogical nature of the colloid and the moisture equivalent, exchange capacity, and base saturation of several sandy loam and sandy soils are discussed. In profiles of Red Bay, Norfolk, and Tifton fine sandy loams exchange capacity, Ca, Mg, and K decreased with depth but clay content and aluminum saturation of these soils increased. In other Coastal Plain soils, namely Klej, Lakeland, and Bladen profiles, a low major base saturation was found with pH values above 5.0 and a high amount of exchangeable aluminum. Calcareous soils and montmorillonitic soils which also usually overlie calcareous material such as Pompano, Felda, and Sunniland sands contained appreciable aluminum extracted by neutral N NH₄OAc. Titration curves were made of clays from several soils which differed in the vermiculite, montmorillonite, kaolinite, quartz, and gibbsite content and considerably different buffering capacities were observed. X-ray diffraction patterns indicated that the mineralogical nature of the clay fraction is rather similar in all horizons of any particular soil profile with no consistent accumulation of one mineral over another. The significance of the exchange complex of these colloids is discussed in terms of major bases, aluminum, and pH. Examples of the accumulation of phosphate and heavy metals are given.
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