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Calcium Salts and Mechanical Stress Effects on Water‐Dispersible Clay of Oxisols
Author(s) -
Fontes M. P. F.,
Gjorup G. B.,
Alvarenga R. C.,
Nascif P. G. S.
Publication year - 1995
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1995.03615995005900010034x
Subject(s) - oxisol , calcium , dispersion (optics) , chemistry , mineralogy , materials science , soil water , soil science , geology , physics , optics , organic chemistry
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 CaCl 2 , CaSO 4 , and CaCO 3 . 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 CaCO 3 . Calcium chloride and CaSO 4 yielded very low amounts of WDC in the range of 1 to 20 g kg −1 .