Nitrogen-rich microbial products provide new organo-mineral associations for the stabilization of soil organic matter

Kopittke, Peter M., Hernandez-Soriano, Maria C., Dalal, Ram C., Finn, Damien, Menzies, Neal W., Hoeschen, Carmen and Mueller, Carsten W. (2017) Nitrogen-rich microbial products provide new organo-mineral associations for the stabilization of soil organic matter. Global Change Biology, . doi:10.1111/gcb.14009


Author Kopittke, Peter M.
Hernandez-Soriano, Maria C.
Dalal, Ram C.
Finn, Damien
Menzies, Neal W.
Hoeschen, Carmen
Mueller, Carsten W.
Title Nitrogen-rich microbial products provide new organo-mineral associations for the stabilization of soil organic matter
Journal name Global Change Biology   Check publisher's open access policy
ISSN 1365-2486
1354-1013
Publication date 2017-12-22
Year available 2017
Sub-type Article (original research)
DOI 10.1111/gcb.14009
Open Access Status Not yet assessed
Total pages 9
Place of publication Chichester, West Sussex United Kingdom
Publisher Wiley-Blackwell Publishing
Language eng
Subject 2306 Global and Planetary Change
2304 Environmental Chemistry
2303 Ecology
2300 Environmental Science
Abstract Understanding the cycling of C and N in soils is important for maintaining soil fertility while also decreasing greenhouse gas emissions, but much remains unknown about how organic matter (OM) is stabilized in soils. We used nano-scale secondary ion mass spectrometry (NanoSIMS) to investigate the changes in C and N in a Vertisol and an Alfisol incubated for 365 days with C and N pulse labeled lucerne (Medicago sativa L.) to discriminate new inputs of OM from the existing soil OM. We found that almost all OM within the free stable microaggregates of the soil was associated with mineral particles, emphasizing the importance of organo-mineral interactions for the stabilization of C. Of particular importance, it was also found that N-rich microbial products originating from decomposition often sorbed directly to mineral surfaces not previously associated with OM. Thus, we have shown that N-rich microbial products preferentially attach to distinct areas of mineral surfaces compared to C-dominated moieties, demonstrating the ability of soils to store additional OM in newly formed organo-mineral associations on previously OM-free mineral surfaces. Furthermore, differences in N enrichment were observed between the Vertisol and Alfisol presumably due to differences in mineralogy (smectite-dominated compared to kaolinite-dominated), demonstrating the importance of mineralogy in regulating the sorption of microbial products. Overall, our findings have important implications for the fundamental understanding of OM cycling in soils, including the immobilization and storage of N-rich compounds derived from microbial decomposition and subsequent N mineralization to sustain plant growth.
Keyword Nano-scale secondary ion mass spectrometry
Organo-mineral interactions
Soil carbon cycling
Soil carbon storage
Stable isotopes
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: HERDC Pre-Audit
School of Agriculture and Food Sciences
 
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Created: Sun, 31 Dec 2017, 20:25:54 EST