V. Rasiah

Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)




Rainfall is usually marginal for optimum crop production in the North Central Great Plains. As a result many farmers in this region are installing irrigation systems to supplement rainfall. The most common system installed is the center pivot. However, while this system has a low labor requirement it is costly. Economic reports from South Dakota State University indicate marginal to negative comparisons of irrigated crop production to dryland production. Sprinkler irrigation systems such as side roll, tow lines, hand move, side move with trail lines etc. and surface irrigation depend on root zone soil water storage to extend intervals between irrigations to gain advantages of reduced costs in system design and labor requirements, lower soil evaporation and reduce weed germination. Large root zone water storage is also needed when center pivot systems are towed between two fields with growing crops. The most significant parameters about which information is lacking in making design and associated management decisions concerning the above irrigation options are root zone depth in specific South Dakota soils and root activity in the lower part of the root zone. Questions arise such as: How rapidly and to what depth do roots penetrate in different South Dakota soils? Does root growth cease with flowering? What root density is required in a soil horizon to be significant in water uptake? It was with these questions in mind that a study was initiated into the root length density and water uptake pattern of soybeans in three South Dakota soils.

Library of Congress Subject Headings

Roots (Botany)


Crops and water

South Dakota State University Theses



Number of Pages



South Dakota State University