TY - JOUR
T1 - Mineralogical characterization of the fine fraction (<2μm) of degraded volcanic soils and tepetates in Mexico
AU - Hidalgo, Claudia
AU - Etchevers, Jorge D.
AU - Martínez-Richa, Antonio
AU - Yee-Madeira, Hernani
AU - Calderon, Héctor A.
AU - Vera-Graziano, Ricardo
AU - Matus, Francisco
N1 - Funding Information:
Thanks are due to the CONACYT Project 408899-Z and REVOLSO project ICA4-CT-2001-10052 for the financial support given for the development of experiments. To Jean Marc Lapetite del Laboratoire d´Étude des Transferts en Hydrologie et Environnement (LTHE) from the IRD, Grenoble, France, to Leticia Baños from UNAM-Mexico for the XRD support and Karla A. Barrera Rivera from the University of Guanajuato for their collaboration in the obtention of some of the results of this work.
PY - 2010/8
Y1 - 2010/8
N2 - In Mexico, 70% of the land surface shows some degree of degradation. A substantial portion of these degraded soils are located in the central part of the country, where a high population density exerts unusual pressure on the land. The study of these degraded soils is important because of the ecological, social and economic consequence of this ecosystem component. Two types of degraded volcanic soils were studied in the present research: one coming from tepetates (a volcanic tuff, partially altered and ameliorated for production purposes) and the other, a highly eroded Acrisol developed from old volcanic materials. These soils have not been much studied and are here explored due to their potential to sequester carbon. In studies to focus the relationship between mineralogy and the carbon sequestration it will be necessary to clarify the characteristics of the fine fraction of the soil (<2μm). Clays have been reported to show different mechanisms of association with soil organic matter, in accordance with their nature. In this paper, a mineralogical characterization was made of the fine (2-1μm) and very fine (<1 μm) fractions of these soils, considered to be the most active in the sequestration process. The characterization was initially developed by using X-ray diffraction (XRD). However, the results obtained with this technique were not conclusive. In addition, due to the fact that XRD sometimes requires tedious chemical treatments and take time, it is proposed here to use spectroscopical techniques other that the traditional ones to more accurately define the mineralogical characteristics of the studied fractions. The diffuse reflectance infrared Fourier transform (DRIFT), 27Al magic angle spinning nuclear magnetic resonance (27Al MAS NMR), 29Si magic angle spinning nuclear magnetic resonance (29Si MAS NMR), transmission electron microscopic (TEM), high resolution transmission electron microscopy (HRTEM) and Mössbauer spectroscopy were employed.The fine fractions (< 2 μm) of the degraded soils are made up of low activity clays: tubular halloysites in the Te-Tl tepetates and kaolinites in the Acrisol. The coarse (2-1μm) ones in Te-Tl consist also of cristobalite and albite. In Ac-At, akaganeite, goethite and hematite are the principal Fe-mineral components. For this reason, the restoration techniques proposed for these degraded soils must be complemented with appropriate practices of fertilization providing basic elements (Ca, Mg, K and Na) to the soil that can be rapidly lost, and are associated with low activity of the fine fraction.
AB - In Mexico, 70% of the land surface shows some degree of degradation. A substantial portion of these degraded soils are located in the central part of the country, where a high population density exerts unusual pressure on the land. The study of these degraded soils is important because of the ecological, social and economic consequence of this ecosystem component. Two types of degraded volcanic soils were studied in the present research: one coming from tepetates (a volcanic tuff, partially altered and ameliorated for production purposes) and the other, a highly eroded Acrisol developed from old volcanic materials. These soils have not been much studied and are here explored due to their potential to sequester carbon. In studies to focus the relationship between mineralogy and the carbon sequestration it will be necessary to clarify the characteristics of the fine fraction of the soil (<2μm). Clays have been reported to show different mechanisms of association with soil organic matter, in accordance with their nature. In this paper, a mineralogical characterization was made of the fine (2-1μm) and very fine (<1 μm) fractions of these soils, considered to be the most active in the sequestration process. The characterization was initially developed by using X-ray diffraction (XRD). However, the results obtained with this technique were not conclusive. In addition, due to the fact that XRD sometimes requires tedious chemical treatments and take time, it is proposed here to use spectroscopical techniques other that the traditional ones to more accurately define the mineralogical characteristics of the studied fractions. The diffuse reflectance infrared Fourier transform (DRIFT), 27Al magic angle spinning nuclear magnetic resonance (27Al MAS NMR), 29Si magic angle spinning nuclear magnetic resonance (29Si MAS NMR), transmission electron microscopic (TEM), high resolution transmission electron microscopy (HRTEM) and Mössbauer spectroscopy were employed.The fine fractions (< 2 μm) of the degraded soils are made up of low activity clays: tubular halloysites in the Te-Tl tepetates and kaolinites in the Acrisol. The coarse (2-1μm) ones in Te-Tl consist also of cristobalite and albite. In Ac-At, akaganeite, goethite and hematite are the principal Fe-mineral components. For this reason, the restoration techniques proposed for these degraded soils must be complemented with appropriate practices of fertilization providing basic elements (Ca, Mg, K and Na) to the soil that can be rapidly lost, and are associated with low activity of the fine fraction.
KW - HRTEM
KW - Halloysite
KW - MAS NMR
KW - Mössbauer spectroscopy
KW - Tepetates
UR - http://www.scopus.com/inward/record.url?scp=77955428819&partnerID=8YFLogxK
U2 - 10.1016/j.clay.2009.11.007
DO - 10.1016/j.clay.2009.11.007
M3 - Artículo
SN - 0169-1317
VL - 49
SP - 348
EP - 358
JO - Applied Clay Science
JF - Applied Clay Science
IS - 4
ER -