Document Type

Thesis - Open Access

Award Date

1973

Degree Name

Master of Science (MS)

Department

Agronomy

Abstract

Soil management becomes increasingly important with the advent of irrigation agriculture in semi-arid regions. The limitations of soils and also water must be recognized or major environmental damage can occur when soils are not managed properly. Soils and water may have limitations so severe that irrigation agriculture is not possible because of the salts or sodium already in the soils or which may be derived from the water used. In South Dakota, large areas of land will require special soil management if proposed irrigation projects are to be succcssfu1. As much as 57% of the land in South Dakota (excluding the Badlands and Black Hills) is slightly to strongly saline. Some areas contain a sodium-dispersed or claypan layer in the subsoil that imposes further restrictions to irrigation. If both of these limitation (salinity and dispersed 1ayer) exist, the soil is characterized as a saline-alkali soil. Such soils have soluble salts that can decrease plant growth through reduced availability of water to the plant and a claypan that can restrict the growth of plant roots and the moven1ent of air and water to the subsoil. This claypan layer can also cause a water-1ogged topsoil and can increase the erosion hazard during rains due to low permeability. The workability of the soi1 is greatly reduced if a dispersed layer is present. When wet, the claypan is a dense, sticky mass which on drying becomes a hard, structureless or columnar mass breaking into large clods. Amelioration of these soils is possible through the use of: (a) good quality irrigation water, (b) drainage, (c) soil treatments that can replace sodium on the exchange complex with calcium, and (d) leaching to remove excess salts. The objectives of this study were to evaluate various laboratory simulated treatments in their ability to restore desirable physical and chemical characteristics to these problem soils; to determine the effect of leaching in reducing salt content; and to see what changes have taken place in the cation status of the exchange complex.

Library of Congress Subject Headings

Solonetz soils

Reclamation of land

South Dakota Sate University Theses

Format

application/pdf

Number of Pages

49

Publisher

South Dakota State University

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