Field and laboratory characterization of soil water desorption properties and comparison of plant available water for two Virginia soils

Soil water movement and desorption studies were conducted on two agriculturally important soil series. The soils selected were the Norfolk soil (a fine loamy, siliceous, thermic, Typic Paleudult) and the Cecil soil (a clayey, kaolinitic, thermic, Typic Hapludult). Water desorption properties were investigated in the laboratory and in situ. The soil water desorption curves developed in the laboratory for both soils were relatively uniform. This observation was also true for most horizons for the desorption curves developed from the field data. The results for the B horizons of the Cecil soil showed the greatest variability, with the field data being the most variable. Comparisons of the field and laboratory water contents at given tensions show the field values were lower than laboratory values for horizons with over 40 percent sand and less than 30 percent clay. Field values were higher than laboratory values in the B horizons of both soils. In all other horizons, the field values were close to those obtained in the laboratory. The Norfolk soil was found to contain more plant available water than the Cecil soil. The selection of an upper limit for plant available water estimation is critical, especially for the Norfolk soil. The Cecil soil yielded little water between -.05 and -.30 bars, whereas the Norfolk soil yielded a relatively large amount of water (more than 3 times greater) in this range. This would nearly double the predicted plant available water for the Norfolk soil. Results of this study show that the irrigation management of the Cecil soil would require smaller amounts of water applied frequently, whereas the Norfolk soil could hold larger amounts of plant available water applied less frequently. This would allow more time between irrigations.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Agronomy

Department dc:contributor.department

Agronomy

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1985

Author dc:creator

• Starner, David Eugene

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/10919/53087

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/53087