Microbial function in adjacent subtropical forest and agricultural soil

Brackin, Richard, Robinson, Nicole, Lakshmanan, Prakash and Schmidt, Susanne (2013) Microbial function in adjacent subtropical forest and agricultural soil. Soil Biology & Biochemistry, 57 68-77. doi:10.1016/j.soilbio.2012.07.015


Author Brackin, Richard
Robinson, Nicole
Lakshmanan, Prakash
Schmidt, Susanne
Title Microbial function in adjacent subtropical forest and agricultural soil
Journal name Soil Biology & Biochemistry   Check publisher's open access policy
ISSN 0038-0717
1879-3428
Publication date 2013-02-01
Sub-type Article (original research)
DOI 10.1016/j.soilbio.2012.07.015
Volume 57
Start page 68
End page 77
Total pages 10
Place of publication Kidlington, Oxford, United Kingdom
Publisher Pergamon
Collection year 2014
Language eng
Abstract Soil microbial communities and their activities are altered by land use change; however impacts and extent of these alterations are often unclear. We investigated the functional responses of soil microbes in agricultural soil under sugarcane and corresponding native soil under Eucalyptus forest to additions of contrasting plant litter derived from soybean, sugarcane and Eucalyptus in a microcosm system, using a suite of complimentary techniques including enzyme assays and community level physiological profiles (CLPP). Initially agricultural soil had 50% less microbial biomass and lower enzyme activities than forest soil, but significantly higher nitrification rates. In response to litter addition, microbial biomass increased up to 11-fold in agricultural soil, but only 1.8-fold in forest soil, suggesting a prevalence of rapidly proliferating 'r' and slower growing 'K' strategists in the respective soils. Litter-driven change in microbial biomass and activities were short lived, largely returning to pre-litter addition levels by day 150. Decomposition rates of sugarcane and soybean litter as estimated via CO2 production were lower in agricultural than in forest soil, but decomposition of more recalcitrant Eucalyptus litter was similar in both soils, contradicting the notion that microbial communities specialise in decomposing litter of the dominant local plant species. Enzyme activities and community level physiological profiles (CLPP) were closely correlated to microbial biomass and overall CO2 production in the agricultural soil but not the forest soil, suggesting contrasting relationships between microbial population dynamics and activity in the two soils. Activities of enzymes that break down complex biopolymers, such as protease, cellulase and phenol oxidase were similar or higher in the agricultural soil, which suggests that the production of extracellular biopolymer-degrading enzymes was not a factor limiting litter decomposition. Enzyme and CLPP analyses produced contrasting profiles of microbial activity in the two soils; however the combination of both analyses offers additional insights into the changes in microbial function and community dynamics that occur after conversion of forest to agricultural land.
Keyword Dynamics
Enzymes
CLPP
Sugarcane
Cropping
Deforestation
Soil health
Litter decomposition
Nitrification
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Agriculture and Food Sciences
Official 2014 Collection
 
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