Aerobic respiration of mineral-bound organic carbon in a soil

Dinesh Adhikari; Sarrah M Dunham-Cheatham; Dawit N Wordofa; Paul Verburg; Simon R Poulson; Yu Yang

doi:10.1016/j.scitotenv.2018.09.271

Aerobic respiration of mineral-bound organic carbon in a soil

Sci Total Environ. 2019 Feb 15;651(Pt 1):1253-1260. doi: 10.1016/j.scitotenv.2018.09.271. Epub 2018 Sep 21.

Authors

Dinesh Adhikari¹, Sarrah M Dunham-Cheatham², Dawit N Wordofa³, Paul Verburg⁴, Simon R Poulson⁵, Yu Yang⁶

Affiliations

¹ Department of Civil and Environmental Engineering, University of Nevada, Reno, 1664 N. Virginia Street, Reno, NV 89557, USA; Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA 94550, USA.
² Department of Civil and Environmental Engineering, University of Nevada, Reno, 1664 N. Virginia Street, Reno, NV 89557, USA; Department of Natural Resources & Environmental Science, University of Nevada, Reno, 1664 N. Virginia Street, Reno, NV 89557, USA.
³ Department of Civil and Environmental Engineering, University of Nevada, Reno, 1664 N. Virginia Street, Reno, NV 89557, USA.
⁴ Department of Natural Resources & Environmental Science, University of Nevada, Reno, 1664 N. Virginia Street, Reno, NV 89557, USA.
⁵ Department of Geological Sciences & Engineering, University of Nevada, Reno, 1664 N. Virginia Street, Reno, NV 89557, USA.
⁶ Department of Civil and Environmental Engineering, University of Nevada, Reno, 1664 N. Virginia Street, Reno, NV 89557, USA. Electronic address: yuy@unr.edu.

PMID: 30360257
DOI: 10.1016/j.scitotenv.2018.09.271

Abstract

Associations with minerals can potentially augment soil organic carbon (SOC) stability by reducing the bioavailability and degradation of SOC. However, few studies have directly measured aerobic respiration of mineral-bound SOC. In this study, we investigated the microbial aerobic respiration and bioavailability of ferrihydrite-sorbed glucose (Fh-GLU) and ferrihydrite-sorbed formic acid (Fh-FA) by adding ¹³C-labeled compounds to a soil. During an 11-day incubation, 30.2% of free, non-Fh-sorbed glucose (GLU) and 61.8% of free formic acid (FA) were respired, whereas 4.2% and 27.9% of Fh-GLU and Fh-FA were respired, respectively. Our results demonstrated that Fh-bound GLU/FA had lower bioavailability compared to free organic compounds. Associations with Fh led to greater inhibition in the bioavailability of GLU than that for FA. The priming effects of added compounds on the respiration of native SOC were decreased by their association with Fh. Our results demonstrated that the bioavailability and priming effect of organic compounds depend on their interactions with minerals.

Keywords: Iron oxide; Mineral; Organic carbon; Respiration.