Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School



An adequate supply of phosphorus in the soil is essential for optimum crop production. Phosphorus has often been referred to as the master key to agriculture and to life. South Dakota soils have become depleted in phosphorus as a result of its removal from the soil, primarily by cropping. It is known that in South Dakota only a small percent of the phosphorus which is removed annually by crops is returned to the soil through application of fertilizer or manure. In many soil areas signs of a deficiency of available soil phosphorus are becoming evident. This is indicated by the appearance of phosphorus deficiency symptoms in crops, lower crop yields and the response of crops to the application of phosphate fertilizer. The depletion of soil phosphorus to a level which limits the yields of crops has aroused considerable interest in the use of phosphate fertilizers. The various types of phosphate fertilizers which are available for use include water soluble phosphates, ammonium citrate soluble phosphates, and relatively insoluble phosphate. It is the purpose if this study to compare the efficiency of some of these phosphate fertilizers, varying in solubility, with respect to crop response and uptake of phosphorus, by the growing of plants on South Dakota soils. Fields experiments were conducted on four different soils located in Brookings, Clark, Deuel and McCook counties. The experiments during the first year were located on established stands of alfalfa. Two of the fields were harvested the second year. An additional experiment was laid out using barley as the crop. Brief descriptions of the soils on which the experiments were located are given below: Vienna Loam—Brookings county. This soil is a well-drained soil developed in glacial till of Tazewell age. It occurs on gently sloping landscape. The surface soil is very dark grayish-brown to black, very friable noncalcareous loam. The lower horizons shade to a grayish-brown or brownish-gray color and the soil becomes strongly calcareous at about 20 to 28 inches. Singsaas Silt Loam—Deuel county. This is a well-drained soil developed from glacial till of Cary age on a nearly level slope. This soil has been worked extensively by worms, which have destroyed the zonal profile horizonation. Houdek Loam—Clark county. This soil was developed from loam till of Mankato age. The landscape is nearly level to undulating. It is a well-drained, dark grayish brown, slightly acid (pH 6.4) loam. Silty Clay Loam—McCook county. The soil at the site is an unnamed series occurring on nearly level Mankato ground moraine. It has a strongly developed profile which based on the B horizon characteristics appears to have undergone a slight degree of solonization.

Library of Congress Subject Headings



Includes bibliographical references



Number of Pages



South Dakota State University