Tuesday, November 6, 2007 - 12:00 PM
180-10

Water Retention Properties along a Carbon Dioxide/Temperature Gradient.

Daniel Giménez, Department of Environmental Sciences, Rutgers, The State University of New Jersey, 14 College Farm Road, New Brunswick, NJ 08901-8551, Hyen Chung Chun, Environmental Sciences, Rutgers, The state university of New jersey, 14 College Farm Road, new brunswick, NJ 08901, Lewis Ziska, USDA-ARS, 10300 Baltimore Avenue, Bldg 001, Room 323, BARC-WEST, Beltsville, MD 20705, and Richard Heck, Land Resource Science, University of Guelph, Guelph, ON N1G 2W1, Canada.

There is evidence that increases in carbon dioxide and temperature decrease the amount of macropore in soils. The objective of this study was to quantify water retention properties in experimental sites containing the same soil, but exposed to a natural gradient of carbon dioxide and temperature. Plots located in urban, suburban, and rural areas in Maryland were excavated and filled with the same fallow agricultural soils in 2002. The maximum differences in temperature and carbon dioxide between the urban and the rural plots was about 3° C and 20%, respectively. After five years of exposure, undisturbed samples were taken in triplicate from selected plots at each site and water retention properties were measured at multiple pressure potentials using a combination of hanging columns and pressure extractors. Results will be discussed.