The moisture equivalent of heavy soils. II

Abstract

1. The moisture equivalent of pure clay preparations varies with (a) the chemical composition, (b) the method of separation if centrifuged, (c) the replaceable bases.2. The imbibitional water content also shows a close connection with the above variables.3. Good additive relationships can only be obtained from series of soils of the same nature and in some cases, if taken at the same depth. This is, at any rate in part, due to differences existing in composition and properties between clay separated from soils and subsoils.4. Pure silt fractions from different soils showed marked differences in their chemical composition and moisture equivalent.

Emergence of Crops in Clay Soils of the Central Sudan Rainlands in Relation to Soil Water and Air-Filled Pore Space

“…Since the surface layers of beds were initially saturated with water, this may be compared to Drover's 0-3 atm. percentage and the moisture equivalent of Joseph (1927). Kutilek (1969), also using disturbed soil, reported peak release of water at o-1 atm.…”

Effect of Structural Fe Reduction on Water Sorption by Swelling and Non-Swelling Clay Minerals

“…The degree of aggregation of the clay prior to hydration was also found to be a key parameter that affected the moisture content of the clay, as shown by Josheph [9]. By studying submicroscopic samples from centrifugation of soil samples, Josheph showed that there was a significant difference in water capacity between the original clay, the colloid and the residue [9]. By isolating the colloidal material from soils and undertaking washing and performing cation substitution experiments, Anderson concluded that oxide and salt concentration within the clay are also controlling factors [10].…”

“…This was determined by wetting and drying treatments of clay mineral rich soil prior to measuring the vapour pressure-moisture relationship. The degree of aggregation of the clay prior to hydration was also found to be a key parameter that affected the moisture content of the clay, as shown by Josheph [9]. By studying submicroscopic samples from centrifugation of soil samples, Josheph showed that there was a significant difference in water capacity between the original clay, the colloid and the residue [9].…”