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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Spatial variability of iron oxides in soils from Brazilian sandstone and basalt

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Author(s):
Silva, Laercio Santos [1] ; Marques Junior, Jose [1] ; Barron, Vidal [2] ; Gomes, Romario Pimenta [1] ; Teixeira, Daniel De Bortoli [3] ; Siqueira, Diego Silva [1] ; Vasconcelos, Vinicius [4]
Total Authors: 7
Affiliation:
[1] Sao Paulo State Univ, Fac Agr & Vet Sci, Res Grp CSME Soil Characterizat Specif Management, Dept Soils & Fertilizers, FCAV, UNESP, Jaboticabal, SP - Brazil
[2] Cordoba Univ, Dept Agron, Cordoba - Spain
[3] Univ Marilia, Unimar, Ctr Agr Sci, Sao Paulo, SP - Brazil
[4] Univ Brasilia, UnB, Dept Geog, Brasilia, DF - Brazil
Total Affiliations: 4
Document type: Journal article
Source: CATENA; v. 185, FEB 2020.
Web of Science Citations: 0
Abstract

Iron oxides as goethite (Gt) and hematite (Hm) are key minerals to better understand the soil-landscape relationships. Soil samples were collected at three stages of landscape dissection from the geological formations of Vale do Rio do Peixe (sandstone) and Serra Geral (basalt) in the Western Paulista Plateau (WPP), Brazil. Both iron oxides were quantified by X-ray diffraction (XRD) and diffuse reflectance spectroscopy (DRS), and the results were subjected to geostatistical analysis in order to assess the usefulness of DRS for characterizing the spatial variability in Gt and Hm. The prevalence and spatial variability of Hm and Gt in the soils were governed by the sandstone/basalt lithological contrast and landscape dissection. Iron oxides in the clay fraction exhibited high spatial variability over a large area and can be robust indicators of geological diversity and landscape dissection in pedoenvironments with low or high contents of iron oxides. Goethite had the highest spatial variability. Based on the spatial pattern of the differences between DRS and XRD estimates, the saturated red color in soil made DRS less useful for quantifying Hm in environments with high iron oxide contents. The maps indicate the sensitivity of XRD and DRS techniques to represent Hm and Gt spatial variability patterns. Gt was more sensitive to landscape dissection while Hm sensitive to lithology. Thus, the DRS technique is efficient in characterizing the spatial variability of these soil oxides in large areas, even considering the complex relations between soil and landscape. (AU)

FAPESP's process: 18/15694-1 - Spatial variability of iron oxides and emission of nitrogen gases (NOx) in soils of the São Paulo Western plateau
Grantee:Laércio Santos Silva
Support Opportunities: Scholarships abroad - Research Internship - Doctorate
FAPESP's process: 17/01704-2 - Spatial variability of iron oxides and phosphate adsorbed in soil Western Paulista Plateau
Grantee:Laércio Santos Silva
Support Opportunities: Scholarships in Brazil - Doctorate