Cationic equilibria in selected soils and soil materials
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Date
1970-12
Authors
Laker, Michiel Christiaan
Journal Title
Journal ISSN
Volume Title
Publisher
University of the Free State
Abstract
The relationship between exchangeable potassium and
ARKe was studied for four agronomically-important soils of the
O.F.S. Region and two commercial clays. Some attention was
also given to the Q/I and Gapon relationships for these soils
and claysc The effects of some factors, e.g. sodium level
and clay:solution ratio, on these parameters were also investigatedo
Linear relationships between Kex and ARKe were found for
all soils and clays used. In most cases the graphs relating
Kex to ARKe had intercepts different from zeroo At extremely
high levels of K saturation in bentonite the slopes of the
graphs changed and different linear relationships were obtained,
the slopes of the upper portions being lower than
those of the lower portions.
At high Kex levels a fairly good numerical similarity
between -∆K and Kex was found in most caseso At Kex level near EK , i.e. that level of Kex where ARKe becomes zero,
-∆KO decreased relative to Kex. At these low Kex levels
-∆KO was therefore not a good indication of Kex.
PBCK proved to be a very constant property of a soil or
clay, being unaffected by most experimental conditions and
by level of K saturation. The PBCK values of these soils
were very lowo PBCK of bentonite was strongly influenced
by clay: solution ratio when ∆K values were expressed as me
per 100g clay.
Increased sodium levels changed the relationships between
Kex and ARKe, but did not cause poorer relationships
between these two parameters. The magnitude of the effect
of sodium was a function of the amount of sodium brought into
the system and the latter was largely a function of the
CEC of a soil.
Description
Keywords
Cationic polymerization, Addition polymerization, Soils, Thesis (Ph.D (Soil Science))--University of the Free State, 1970, Soil materials