HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Fontes, M. P. F. Articles by Nascif, P. G. S. Search for Related Content PubMed Articles by Fontes, M. P. F. Articles by Nascif, P. G. S. Agricola Articles by Fontes, M. P. F. Articles by Nascif, P. G. S.

Calcium Salts and Mechanical Stress Effects on Water-Dispersible Clay of Oxisols

Departmento de Solos, Universidade Federal de Viçosa, 36570, Viçosa, MG, Brazil

* Corresponding author.

ABSTRACT

It can be hypothesized that clay dispersion as a function of lime application and mechanical stresses is an important factor in the deterioration of physical conditions of some Brazilian Oxisols. Therefore, a laboratory study was conducted to test the influence of these varaibles on clay dispersion. Different water-dispersible clay (WDC) contents and incubation times varying from 0 to 50 d were tested. The Ca salts used were CaCl₂, CaSO₄, and CaCO₃. The methodologies utilized to measure WDC and vary mechanical stresses were: (i) manual soil sample shaking for 1 min with a glass rod (low-energy stirring system, LESS); and (ii) shaking in a reciprocating shaker for 3 h (high-energy shaking system, HESS). The LESS did not yield significant amounts of WDC regardless of the Ca salt used. The HESS yielded approximately 120 to 311 g kg^–1 of WDC by itself or when combined with CaCO₃. Calcium chloride and CaSO₄ yielded very low amounts of WDC in the range of 1 to 20 g kg^–1.

Received for publication January 24, 1994.