Microbial response to the addition of soluble organic substrates

Hoyle, F.C.ORCID: 0000-0001-6946-918X and Murphy, D.V. (2007) Microbial response to the addition of soluble organic substrates. Soil Research, 45 (7). p. 559.

Abstract

Soil microbial activity is often limited by the absence of readily available carbon (C) based substrates. Addition of a range of soluble organic substrates to soil has been shown to either accelerate or constrain the rate of CO2-C evolution. The aim of this study was to investigate the capacity of the microbial population to become activated in response to small additions of glucose-C (10–50 µg C/g soil) and 19 other soluble organic substrates (30 µg C/g soil) in soil either amended or not with cellulose. Rapid utilisation (equivalent to 25–35%) of added glucose was demonstrated in an initial flush of respiratory activity measured as CO2-C. However, the cumulative amount of respired C in 23 days indicated no additional release of CO2-C from the native soil organic matter (SOM) following application of glucose to soils, and a highly variable secondary phase of C mineralisation distinct from the initial glucose mineralisation phase. Although several C substrates resulted in the evolution of ‘extra’ CO2-C, no obvious association was observed between the response and the chemical structure of each substrate.

Item Type:	Journal Article
Publisher:	CSIRO Publishing
Copyright:	© CSIRO 2007
URI:	http://researchrepository.murdoch.edu.au/id/eprint/62381

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