Causes of morphological discontinuities in soils of Depressão Central, Rio Grande do Sul State, Brazil

Scientia Agricola

Cristiane Regina Michelon²  Antonio Carlos De Azevedo¹  Fabrício De Araújo Pedron¹  Ricardo Simão Diniz Dalmolin¹  Sidinei Klochnner Stürmmer²  Juliana Gonçalves²  Sérgio Luis De Jesus¹ 

[1] ,UFSM Programa de Pós-Graduação em Ciência do Solo Santa Maria RS ,Brasil

关键词: soil morphology;    subtropical soils;    soil discontinuity;    morfologia do solo;    solos subtropicais;    descontinuidades pedogenéticas;   

DOI  :  10.1590/S0103-90162010000300010

来源: SciELO

【 摘 要 】

Morphological, particularly textural, discontinuities between horizons increase soil erodibility in Depressão Central, Rio Grande do Sul State (Brazil). Characterization of such discontinuities would help to understand landscape evolution and to model near-surface hydrology. The objective of this research was to explore the relationship between morphological discontinuity and deposition of transported materials during pedogenesis. Transported material was meant to be mineral particles found in the soil profile, transported probably by water or gravity, that were not present neither in the parent material nor derived from it. Five soils of this region (two Alfisols, two Ultisols and one Mollisol) were sampled and morphological, sand grain size statistics, chemical and mineralogical analyses were used to search for evidences of deposition of transported materials. Two soils had abrupt textural change but no evidence of deposition of transported materials, two soils had less contrasting morphology and some characteristics that are possibly related to deposition, and one soil had no morphological discontinuity, but had deposition of material enriched in magnetite-maghemite in the sand fraction of the A horizon. Therefore, there were no relationship between morphological discontinuity and deposition of transported materials for these profiles in the Depressão Central.

【 授权许可】

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