Document Type

Thesis - Open Access

Award Date


Degree Name

Doctor of Philosophy (PhD)




This study is an outgrowth of preliminary investigation by Hovland and Wesley to determine environmental conditions required by plants to establish vegetative cover on highway back slopes. From the nutritional phase of this study it was determined that nitrogen and phosphorus were the only deficient elements in the four exposed subsoils that were investigated. Deficient nutrients are supplied to exposed subsoils by the application of commercial fertilizer. The fertilizer is usually applied on the soil surface and seldom worked more than a few inches down onto the soil. In th Northern Great Plains, this zone of fertilizer placement dries out rapidly and may remain dry for extended periods of time during the growing season. Phosphorus is relatively immobile in the soil and remains in the vicinity of application for an entire season. Under these conditions, plants growing in infertile subsoils may not be able to absorb enough fertilizer phosphorus to sustain growth even though moisture condition below the fertilized layer is sufficient. Therefore, it was essential to determine the effect of moisture stress on fertilizer phosphorus uptake and its relation to stand failures. It was the purpose of this investigation to study the effect of increasing soil moisture tensions on the uptake of fertilizer phosphorus by plants grown on subsoil materials.

Library of Congress Subject Headings

Soil moisture
Phosphorus -- Physiological effect


Includes bibliographical references



Number of Pages



South Dakota State University