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- Paul White and Dr. Charles W. Rice
- Department of Agronomy
- Kansas State University
- Manhattan, KS
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- Atmospheric CO2 levels have increased from 260 to 370 ppmv
(IPPC, 2004).
- Increasing soil C storage may assist in offsetting increases in CO2
due to fossil fuel emissions until cleaner fuel technology is available
on a large scale.
- Understanding dynamics of C flow in differently managed ecosystems will
be important to forecast C-sequestration effectiveness and extent.
- Possible manipulation of ecosystem to increase soil C storage potential
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- During one growing season:
- Measure the mineralization of 13C-labeled plant residue
- Measure the changes in soil TC and TN
- Measure the changes in soil TC and 13C in macro- and
microaggregates
- Determine microbial community changes in response to added residue
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- Continuous Sorghum under No-Tillage (NT) and Conventional Tillage (CT)
- 4 Blocks
- 2 Residue Levels: Control (no residue) and 0.5% by weight
- 7 Sample Times: 0, 3, 16, 25, 40, 68, and 159 d
- Data analyzed using SAS v9 Proc Mixed and means separated at the 5%
significance level (SAS Institute, Cary N.C).
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- Addition of 0.5% by weight grain sorghum residue did not have
significant impacts on soil C and N dynamics during the growing season Indicating
relative macro system stability
- Decomposition kinetics and residual 13C levels were not
different between tillage regimes
Label detectable throughout growing season
- 13C Aggregate analysis and microbial lipids analysis may
indicate management effects at a finer resolution
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25
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- Geronimo Watson, Karina Fabrizzi, Jamey Duesterhaus, and undergraduate
lab techs
- Dr. Chuck Rice
- Dr. Mary-Beth Kirkham
- Dr. Clenton Owensby
- Dr. Dallas Pederson
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