Date of Award:
5-1974
Document Type:
Thesis
Degree Name:
Master of Science (MS)
Department:
Plants, Soils, and Climate
Department name when degree awarded
Soil Science and Biometrology
Committee Chair(s)
J. J. Jurinak
Committee
J. J. Jurinak
Committee
R. L. Smith
Committee
L. King
Abstract
Two soils were used in this soil column study. Yolo loam soil a non-calcareous, non-gypsiferous soil from central California and Vernal soil a calcareous soil from eastern Utah.
Initial studies were conducted where the solubilities of pure CaC03 and CaS04 ' 2H20 were determined in the presence of Logan river water, a KCl solution (2.8 mmhos/cm) and a K2S04 solution (2. 7 mmhos/cm). Gypsum was more soluble in the KCl solution than in the K2S04 solution. The solubility product of both gypsum and lime were determined from the analytical data. The formation of CaS040 and CaC030 ion pairs were considered to be the most important complex ions present. A reasonable agreement was observed between the theoretical values of Ksp and the calculated Ksp. Essentially the same results were obtained when these waters were used in leaching the columns of Yolo and Vernal soil columns
The solubility of gypsum was greatest using the KCl leaching' solution and least using the K2S04 leaching solution. Logan river water gave intermediate values.
Calcium carbonate was most soluble in the K2S04 leaching solution and les s in the KCl solution. It was found that measuring the Ca2+ concentration in the effluent was a more reliable index to steady state condition than using an electrical conductivity measurement. Unsaturated flow removed more salt per unit volume of effluent than saturated flow. The relative area method was used to analyze the effluent under saturated moisture flow. It was found that a certain amount of Ca2+ derived from gypsum dissolution precipitated in the column as CaC03. This amount was greater than 15% of the Ca2+ dissolved from gypsum.
Checksum
e96c098918ae9a05205696e301bb5a85
Recommended Citation
Alawi, Badier J., "Dissolution and Precipitation of Gypsum in the Soil Under Irrigation" (1974). All Graduate Theses and Dissertations, Spring 1920 to Summer 2023. 2196.
https://digitalcommons.usu.edu/etd/2196
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