Clay Research
Year : 2005, Volume : 24, Issue : 2
First page : ( 145) Last page : ( 157)
Print ISSN : 0255-7193.

Clay illuviation in calcareous vertisols of peninsular India

Satyavathi P.L.A., Ray S.K., Chandran P., Bhattacharyya T., Durge S.L., Raja P., Maurya U.K., Pal D.K.*

Division of Soil Resource Studies, National Bureau of Soil Survey and Land Use Planning, Amravati Road, Nagpur, 440 010

*Corresponding author: E-mail address: paldilip2001@yahoo.com; dkpal@nbsslup.ernet.in

Abstract

In view of diverse understanding on the movement and accumulation of clay particles in Vertisols, a study on seven benchmark calcareous Vertisols representing a climosequence from sub-humid moist to arid dry climate was undertaken. The Vertisols have clay enriched slickensided horizons (Bss) (≥8% absolute increase from the eluvial horizon). The study indicates that the clay enrichment in the Bss horizons due to illuviation of clay particles and their subsequent accumulation in the Bss horizons have been possible because of the dispersion of the clay particles caused by Mg²⁺ and Na⁺ ions when precipitation of soluble Ca²⁺ ions as calcium carbonate (CaCO₃) occurs. The formation of CaCO₃ and the illuviation of clay are two pedogenetic processes occurring simultaneously as comtemporary pedogenic events in drier climate since the late Holocene. Thus, the argilliturbation towards proisotropic pedoturbation has not been able to overtake the clay illuviation in Vertisols under study for thousands of years.

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