TRANSMITTANCE OF LIGHT THROUGH SOIL–WATER SUSPENSIONS FROM B HORIZONS OF SOLONETZIC AND CHERNOZEMIC SOILS

Abstract

A quantitative measurement of the dispersion of colloidal material from B horizons of Solonetzic and Chernozemic soils was determined by standardized measurements of transmittance of light through aqueous suspensions of soil material. The transmittance of light through the suspension was read on a spectrophotometer which was set at a wavelength of 918 mμ to read 100% transmittance through distilled water.Transmittance of light through suspensions from Solonetzic soils was much lower than transmittance through suspensions from Chernozemic soils. Tentative limits have been set which place the soils with transmittance readings of 23% or less in the Solonetzic Order, and those above this in the Chernozemic Order. Using these limits, 67, 98, and 71% of the Solonetz, Solodized Solonetz, and Solod soils, 100, 98, and 76% of the Calcareous, Orthic, and Eluviated Chernozemic soils could be placed in the same orders in the laboratory as they were in the field.