Evaluating soil stabilisation by biological processes using step-wise aggregate fractionation

M. R. Ashman, P. D. Hallett*, P. C. Brookes, J. Allen

*Corresponding author for this work

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

Soil biological processes contribute stability against physical disruption. We present an approach of step-wise fragmentation to assess the role that microbes and organic matter have on soil aggregate stabilisation. Compared to slaking and ultrasound procedures, the approach has a low impact on the microbial biomass. It also does not impose a severe drying stress. Grassland soil was found to be more stable than arable soil. Further examination of the arable soil revealed that increased disruption by shaking caused unstable microaggregates 53-250 mu m in size to fragment, leaving a higher proportion of stable microaggregates in this size range. Carbohydrates, C:N, and basal respiration were found to be higher in the stable microaggregates than the other size fractions. Our results indicate that a distinct size range of soil aggregates exists in which microbial stabilisation dominates. This contradicts other research and questions the usefulness of measuring the biological properties of aggregate size fractions without understanding the physical effects of the fractionation procedure. (C) 2008 Elsevier B.V. All rights reserved.

Original languageEnglish
Pages (from-to)209-215
Number of pages7
JournalSoil & Tillage Research
Volume102
Issue number2
DOIs
Publication statusPublished - Mar 2009
Event17th Triennial International Conference of the International-Soil-Tillage-Research-Organisation - Kiel, Germany
Duration: 27 Aug 20061 Sep 2006

Keywords

  • management
  • carbon
  • organic-matter
  • cultivated soils
  • nitrogen
  • microbial activity
  • dynamics
  • microbial biomass
  • carbohydrate-composition
  • soil aggregate
  • stability
  • hierarchy
  • mechanisms

Cite this