Disentangling the impact of AM fungi versus roots on soil structure and water transport

Author(s)
Hallett, Paul
Feeney, Debbie
Bengough, A Glyn
Rillig, Matthias
Scrimgeour, Charlie M
Young, Iain
Publication Date
2009
Abstract
The relative importance of roots and AM-fungi on soil physical processes was investigated by controlling the presence of roots and AM fungi in pot experiments using a mycorrhiza-defective tomato mutant and a wild-type tomato ('Solanum lycopersizum' L.). Root-Zone and Bulk Soil sections were established by splitting pots into two lengthwise halves using a nylon mesh that contained roots while allowing the free movement of fungal hyphae. Post-incubation microbial populations and fungal biomass were measured and related to soil stability, pore structure and water repellency. Unplanted controls consistently had the least fungal biomass, fatty acids, water-stable aggregates (WSA) and water repellency. Wild-type-planted treatments had significantly more WSA than mycorrhiza-defective treatments (P<0.01). Fluctuations in water content induced by transpiration caused significant changes in soil pore structure, measured using high-resolution X-Ray computer tomography. Porosity and mean pore size increased in soil aggregates from planted treatments, which had larger more heterogeneous pores than those in the unplanted soils. AM fungi accentuated soil stability. However, changes were not linked to repellency and fungal biomass. The presence of plants, regardless of AM fungi, appears to have the greatest impact on increasing soil stability.
Citation
Plant and Soil, 314(1-2), p. 183-196
ISSN
1573-5036
0032-079X
Link
Publisher
Springer Netherlands
Title
Disentangling the impact of AM fungi versus roots on soil structure and water transport
Type of document
Journal Article
Entity Type
Publication

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