Relationships between aggregation and iron oxides in Terra Rossa soils from southern Italy
- 28 February 1991
- journal article
- Published by Elsevier BV in CATENA
- Vol. 18 (1), 51-59
- https://doi.org/10.1016/0341-8162(91)90006-j
Abstract
Thirteen samples from six Terra Rossa profiles of southern Italy were studied to determine the influence of Fe oxides in aggregation. Removal of all the Fe oxides by the citrate-bicarbonate-dithionite treatment resulted, in all samples, in a decrease in the proportion of the silt plus sand fraction and an increase in the clay fraction. The change in the particle size distribution (PSD) was highly correlated with the total Fe oxide content and with the hematite content but not so well correlated with the goethite content. When the samples were treated with acid NH4-oxalate to remove the poorly crystalline Fe oxides, there was a decrease in the proportion of the sand fraction and, in general, an increase in the proportion of silt and little or no increase in the proportion of clay; the change in PSD was better correlated with the ratio oxalate-extractable Si/oxalate-extractable Fe than with any other single property. This indicates that silica may contribute to aggregation, probably by forming bridges between Fe oxides and other soil particles.Keywords
This publication has 12 references indexed in Scilit:
- Iron oxides and particle aggregation in B horizons of some Italian soilsGeoderma, 1989
- Iron oxide mineralogy of terra rossa and its genetic implicationsGeoderma, 1989
- Fragipan Bonding by Silica and Iron Oxides in a Soil from Northwestern ItalySoil Science Society of America Journal, 1989
- Interaction of aluminum and iron oxides and clay minerals and their effect on soil physical properties: A reviewCommunications in Soil Science and Plant Analysis, 1989
- Silica in Duric Soils: I. A Depositional ModelSoil Science Society of America Journal, 1987
- Use of the Kubelka—Munk theory to study the influence of iron oxides on soil colourEuropean Journal of Soil Science, 1986
- Identification of Soil Iron Oxide Minerals by Differential X-ray DiffractionSoil Science Society of America Journal, 1981
- Characteristics of Silica Sorption and Solubility as Parameters to Evaluate the Surface Properties of Tropical Soils: I. The Index of Silica ReactivitySoil Science Society of America Journal, 1977
- Differenzierung der Eisenoxide des Bodens durch Extraktion mit Ammoniumoxalat-LösungJournal of Plant Nutrition and Soil Science, 1964
- Studies on soluble silica in soils. I. The sorption of silicic acid by soils and mineralsSoil Research, 1963