About Us | Help Videos | Contact Us | Subscriptions



This article in SSSAJ

  1. Vol. 59 No. 1, p. 224-227
    Received: Jan 24, 1994

    * Corresponding author(s):
Request Permissions


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

  1. M. P. F. Fontes ,
  2. G. B. Gjorup,
  3. R. C. Alvarenga and
  4. P. G. S. Nascif
  1. Departmento de Solos, Universidade Federal de Viçosa, 36570, Viçosa, MG, Brazil



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.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © . Soil Science Society of America