HR: 09:15h
AN: B51B-06    [PDF]
TI: Monitoring Soil Carbon Inputs and Changes with Crop Type and Management Practice Using Pyrolysis-Molecular Beam Mass Spectrometry
AU: Leventhal, J
EM: jleventhal@wideopenwest.com
AF: Diversified Geochemistry, 8944 W. Warren Dr., Lakewood, CO 80227
AU: * Magrini-Bair, K A
EM: kim_magrini@nrel.gov
AF: National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, CO 80401
AU: Hoover, C M
EM: choover@fs.fed.us
AF: USDA Forest Service Northeastern Research Station, P. O. Box 267, Old Route 6, Irvine, PA 16329
AU: Doyle, G L
EM: gdoyle@grl.ars.usda.gov
AF: Grazing Lands Research Laboratory, 7207 W. Cheyenne St., El Reno, OK 73036
AU: Follett, R L
EM: rfollett@lamar.colostate.edu
AF: USDA-ARS, 301 S. Howes, Room 407, Fort Collins, CO 80522
AU: Kimble, J
EM: john.kimble@usda.gov
AF: USDA-NRCS-NSSC, 100 Centennial Mall North, Lincoln, NE 68506
AU: Davis, M F
EM: mark_davis@nrel.gov
AF: National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, CO 80401
AU: Evans, R J
EM: bob_evans@nrel.gov
AF: National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, CO 80401
AB: With the increasing need to produce more renewable bioenergy products comes the need to assess the impacts of these agricultural cropping practices on soil carbon inputs and changes. In addition, the anticipated increased use of short rotation woody crops for biomass and bioenergy programs requires that we improve our understanding of the effects of management on soil quality and soil organic matter. We have developed an atmospheric pressure rapid pyrolysis technique that can analyze up to 150 samples per day with direct sampling molecular beam mass spectrometry (py-MBMS). The advantage of this technique is that complex biomaterials can be rapidly pyrolyzed and subsequent fragment condensation reduced which provides molecular data for both light and heavy pyrolysis products. Because of the chemical richness of the resultant mass spectra, we use multivariate statistical analysis techniques to provide efficient pattern recognition and identify major pyrolysis products. These products can then be used to characterize soil organic matter content and composition. Preliminary results from 0-5 cm soils cores taken from soils that were cropped with either continuous till or no till sorghum or soybeans show that we can easily distinguish between till and no till regardless of crop type. Analysis of depth increments of forest soils that experienced a chronosequence of wind disturbances showed that we could distinguish depth, location, and recent and older soil organic matter species of the soil cores with this technique. Analysis of well-characterized CRP (Conservation Reserve Program) soils again allowed us to distinguish depth and location and to accurately predict soil microbial biomass contents. We will present these results and discuss their implications for quantitatively assessing the impacts of bioenergy cropping on soil organic matter.
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2003 Fall Meeting