Document Type
Article
Publication Date
2006
Abstract
Techniques for measuring soil organic C (SOC) turnover in production fields are needed. The objectives of this study were to propose and test nonisotopic and 13 C stable isotopic techniques for assessing SOC turnover. Based on SOC equilibrium and mass balance relationships, an equation was derived: NHC/SOC initial=[1/(SOC× k NHC)](dSOC/dt)+ k SOC/k NHC, where dSOC/dt is the annual change in SOC, NHC is nonharvested C returned to soil, k SOC is the annual mineralization rate of SOC, and k NHC is the annual mineralization rate of NHC. This equation was used to calculate maintenance rates. An isotopic approach based on simultaneously solving the equations was developed to determine C budgets:(i) SOC retained=[SOC final (Δ soil final− Δ PCR)/(Δ SOCretained− Δ PCR)];(ii) Δ SOC retained= Δ soc initial−[ε ln (SOC retained/SOC initial)],(iii) Δ PCR= Δ NHC−[ε ln (PCR/NHC)]; and (iv) SOC final
Publication Title
Agronomy journal
Volume
98
Issue
3
First Page
443
Last Page
450
DOI of Published Version
10.2134/agronj2005.0066
Publisher
American Society of Agronomy
Rights
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S.
Recommended Citation
Clay, D. E., Carlson, C. G., Clay, S. A., Reese, C., Liu, Z., Chang, J., & Ellsbury, M. M. (2006). Theoretical derivation of stable and nonisotopic approaches for assessing soil organic carbon turnover. Agronomy Journal, 98,444-450.