Short-Term Changes in Labile Soil C and N Fractions Under Soybeans Exposed to Elevated CO2. (6039)
Authors:
A.L. Peralta* - Univ. of Illinois at Urbana-Champaign M.M. Wander - Univ. of Illinois at Urbana-Champaign
Abstract:
Due to elevated levels of anthropogenic CO2, plant growth has been found to increase along with decomposition rates, litter production, and rhizodeposition (via an increase of fine root production and turnover). The increase in plant production and decomposition rates may result in increased formation of soil organic matter (SOM). The current study focuses on quantifying total and labile stocks of soil organic C and N accumulated throughout depths down to 1-m from a soybean Free-Air Concentration Enrichment (SoyFACE) site located at the University of Illinois at Urbana-Champaign campus. Soil samples from the beginning of the experiment were compared to samples taken after two complete soybean-corn rotations to determine if elevated [CO2] has affected SOM formation. The coarse particulate organic matter (POM) fraction, a fraction that contains labile nutrients, was recovered and analyzed to assess C mineralization potential, while the Illinois Soil N-Test (ISNT) was performed in order to recover information on plant-available N. Preliminary ISNT results suggest that there was no difference in plant-available N where soybeans were exposed to ambient versus elevated [CO2] conditions. Analyses of C and N content in whole soil and POM were completed using combustion analysis, and these results will be discussed further.
Speaker Information: Ariane Peralta, Univ. of Illinois at Urbana-Champaign, 2318 W. John St. Apt. C, Champaign, IL 61821; Phone: 217.390.3429; E-mail: [email protected]
Session Information: Wednesday, November 3, 2004, 12:00 PM-2:00 PM Presentation Start: 12:00 PM (Poster Board Number: 2725)
