Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Plants, Soils, and Climate

Committee Chair(s)

Alvin R. Southard


Alvin R. Southard


Raymond W. Miller


It is necessary to study the genesis of the Payson and Trenton polypedons in northern Utah to understand why the Payson polypedon is an Alfisol, while the Trenton polypedon is a Mollisol. Even though the soil-forming factors appear similar, the soils differ at the order level. Two pedons, one belonging to the Payson polypedons and the other belonging to the Trenton polypedon, have been described and sampled by genetic horizons. Both pedons have essentially the same climate, slope, age, elevation, and are developed on the parent material of Lake Bonneville sediments.

The differences in physical, chemical and mineralogical properties among the horizons in the same pedon and between the Payson and Trenton pedons is due to differences in deposition as alluvium or lacustrine sediments during different periods.

The high amount of exchangeable sodium in both pedons reflects the development of texture in natric horizons and helps the movement of fine clay and organic matter from the eluvial to the illuvial horizons.

The light color of the surface of the Payson pedon is related to high amounts of calcium carbonate in the Al horizon, bleaching of soil particles within the structural units by sodium, and the presence of large amounts of light-colored minerals in the epipedon of the Payson soil.