Quantification of aluminium in soil of the Solimões Formation, Acre State, Brazil

Revista Brasileira de Ciência do Solo

Thiago Andrade Bernini²  Marcos Gervasio Pereira¹  Lúcia Helena Cunha Dos Anjos¹  Daniel Vidal Perez¹  Ademir Fontana¹  Sebastião Barreiros Calderano¹  Paulo Guilherme Salvador Wadt¹ 

[1] ,UFRRJSeropédica RJ ,Brazil

关键词: exchangeable aluminium;    sedimentary material;    smectite;    western Amazonia;    alumínio trocável;    material sedimentar;    esmectita;    Amazônia ocidental;   

DOI  :  10.1590/S0100-06832013000600015

来源: SciELO

【 摘 要 】

The variety of soils in the State of Acre is wide and their chemical profiles are still not fully understood. The nature of the material of origin of these soils is indicated by the high aluminium (Al) content, commonly associated with high calcium (Ca) and magnesium (Mg) contents. The study objective was to use different methods to quantify Al in soils from toposequences formed from material of a sedimentary nature originating from the Solimões Formation, in Acre, Brazil. Trenches were opened at three distinct points in the landscape: shoulder, backslope and footslope positions. Soil samples were collected for physical, chemical, mineralogical analyses. The Al content was quantified using different methods. High Al contents were found in most of these horizons, associated with high Ca and Mg levels, representing the predominant cations in the sum of exchangeable bases. The mineralogy indicates that the soils are still in a low weathering phase, with the presence of significant quantities of 2:1 minerals. Similar Al contents were determined by the methods of NaOH titration, xylenol orange spectrometry and inductively coupled plasma optical emission spectrometry. However, no consistent data were obtained by the pyrocatechol violet method. Extraction with KCl overestimated the exchangeable Al content due to its ability to extract the non-exchangeable Al present in the smectite interlayers. It was observed that high Al contents are related to the instability of the hydroxyl-Al smectite interlayers.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License