Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School



Farmers and ranchers are becoming more interested each year in supplemental irrigation, particularly where water sources such as permanent streams, rivers and underground aquifers are available. Many of these waters are of doubtful quality and if used for irrigation along with improper management could inducement unfavorable soil conditions, both chemical and physical. Western United States has numerous examples of irrigation projects that have failed because if the use of waters of inferior quality. Several of the surface flooding waters in western South Dakota are abnormally high in total soluble salts and contain high concentrations of sodium and bicarbonate. The Mormon River Project was abandoned by the Bureau of Reclamation because of the high salt and high sodium content of the waters of this river, and development of the Grand River Project is being held in abeyance pending further investigations which are in progress at the present time. A development farm near the Shadehill reservoir on the Grand River has been established to study on a field basis the effects such water has in the soils of this locality. The nature of the Grand River water is such that a moderately high sodium ion content is combined with a bicarbonate ion content approximately equivalent to the alkaline earths. The principal objective of the study reported here within is to determine to what extent the ration of the concentration of bicarbonate ion to the sum of calcium plus magnesium ions affects the exchangeable sodium and soluble salt status of the soil. When irrigation water becomes the soil solution it suffers a shrinkage in volume, because of transpiration and evaporation, resulting frequently in precipitation of the least soluble constituents, which in this case are calcium and magnesium carbonates. The soluble sodium percentage of the soil solution then increases, favoring adsorption of sodium in the cation exchange of the soil. Adsorption of sodium by the cation exchange complex beyond the point of 12 to 15 percent of the cation exchange capacity results almost without exception in deleterious physical and chemical effects, These effects are those characteristically associated with true alkali solid, for example, extreme swelling and shrinkage, high plasticity, poor aeration poor tilth, high pH and dispersion of organic and inorganic collcide.

Library of Congress Subject Headings

Irrigation farming
Soils -- Sodium content


Includes bibliographical references



Number of Pages



South Dakota State University


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