Plant exudates improve the mechanical conditions for root penetration through compacted soils

Ewan Ebenezer Oleghe; Muhammad Naveed; Elizabeth M. Baggs; Paul David Hallett

doi:10.1007/s11104-017-3424-5

Plant exudates improve the mechanical conditions for root penetration through compacted soils

Ewan Ebenezer Oleghe, Muhammad Naveed, Elizabeth M. Baggs, Paul David Hallett

Research output: Contribution to journal › Article › peer-review

52 Citations (Scopus)

11 Downloads (Pure)

Abstract

Background and Aim: Plant exudates greatly affect the physical behaviour of soil, but measurements of the impact of exudates on compression characteristics are missing. Our aim is to provide these data and explore how plant exudates may enhance the restructuring of compacted soils following cycles of wetting and drying.
Methods: Two soils were amended with Chia (Salvia hispanica) seed exudate at 5 concentrations, compacted in cores to 200 kPa stress (equivalent to tractor stress), equilibrated to -50 kPa matric potential, and then compacted to 600 kPa (equivalent to axial root stress) followed by 3 cycles of wetting and drying and recompression to 600 kPa at -50 kPa matric potential. Penetration resistance (PR), compression index (C_C) and pore characteristics were measured at various steps.
Results: PR decreased and C_C increased with increasing exudate concentration. At 600 kPa compression, 1.85 mg exudate g^-1 soil increased C_C from 0.37 to 0.43 for sandy loam soil and from 0.50 to 0.54 for clay loam soil. After 3 wetting-drying cycles the clay loam was more resillient than the sandy loam soil, with resilience increasing with greater exudate concentration. Root growth modelled on PR data suggested plant exudates significantly eased root elongation in soil.
Conclusion: Plant exudates improve compression characteristics of soils, easing penetration and enhancing recovery of root induced soil compaction.

Original language	English
Pages (from-to)	19-30
Number of pages	12
Journal	Plant and Soil
Volume	421
Issue number	1-2
Early online date	25 Sept 2017
DOIs	https://doi.org/10.1007/s11104-017-3424-5
Publication status	Published - Dec 2017

Bibliographical note

ACKNOWLEDGEMENTS
Funding for this project was provided by Tertiary Education Trust Funds (TETFund) and Ambrose Alli University. We wish to thank Annette Raffan for technical support. M. Naveed is funded by the Biotechnology and Biological Sciences Research Council (BBSRC) project ‘Rhizosphere by Design’ (BB/L026058/1).
Open access via Springer Compact Agreement

Keywords

plant exudates
void ratio
cone penetration resistance
compression index
root growth modelling

Access to Document

10.1007/s11104-017-3424-5Licence: CC BY

Plant exudates improve the mechanical conditions for root penetration through compacted soils
© The Author(s) 2017 This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
Final published version, 1.1 MBLicence: CC BY

Paul Hallett
- Biological Sciences, Aberdeen Centre For Environmental Sustainability - Chair in Soil Physics
Person: Academic

Cite this

@article{7261a64e8aae4435a63293b033a95b3a,

title = "Plant exudates improve the mechanical conditions for root penetration through compacted soils",

abstract = "Background and Aim: Plant exudates greatly affect the physical behaviour of soil, but measurements of the impact of exudates on compression characteristics are missing. Our aim is to provide these data and explore how plant exudates may enhance the restructuring of compacted soils following cycles of wetting and drying.Methods: Two soils were amended with Chia (Salvia hispanica) seed exudate at 5 concentrations, compacted in cores to 200 kPa stress (equivalent to tractor stress), equilibrated to -50 kPa matric potential, and then compacted to 600 kPa (equivalent to axial root stress) followed by 3 cycles of wetting and drying and recompression to 600 kPa at -50 kPa matric potential. Penetration resistance (PR), compression index (CC) and pore characteristics were measured at various steps.Results: PR decreased and CC increased with increasing exudate concentration. At 600 kPa compression, 1.85 mg exudate g-1 soil increased CC from 0.37 to 0.43 for sandy loam soil and from 0.50 to 0.54 for clay loam soil. After 3 wetting-drying cycles the clay loam was more resillient than the sandy loam soil, with resilience increasing with greater exudate concentration. Root growth modelled on PR data suggested plant exudates significantly eased root elongation in soil.Conclusion: Plant exudates improve compression characteristics of soils, easing penetration and enhancing recovery of root induced soil compaction.",

keywords = "plant exudates, void ratio, cone penetration resistance, compression index, root growth modelling",

author = "Oleghe, {Ewan Ebenezer} and Muhammad Naveed and Baggs, {Elizabeth M.} and Hallett, {Paul David}",

note = "ACKNOWLEDGEMENTS Funding for this project was provided by Tertiary Education Trust Funds (TETFund) and Ambrose Alli University. We wish to thank Annette Raffan for technical support. M. Naveed is funded by the Biotechnology and Biological Sciences Research Council (BBSRC) project {\textquoteleft}Rhizosphere by Design{\textquoteright} (BB/L026058/1). Open access via Springer Compact Agreement",

year = "2017",

month = dec,

doi = "10.1007/s11104-017-3424-5",

language = "English",

volume = "421",

pages = "19--30",

journal = "Plant and Soil",

issn = "0032-079X",

publisher = "Springer Netherlands",

number = "1-2",

}

TY - JOUR

T1 - Plant exudates improve the mechanical conditions for root penetration through compacted soils

AU - Oleghe, Ewan Ebenezer

AU - Naveed, Muhammad

AU - Baggs, Elizabeth M.

AU - Hallett, Paul David

N1 - ACKNOWLEDGEMENTS Funding for this project was provided by Tertiary Education Trust Funds (TETFund) and Ambrose Alli University. We wish to thank Annette Raffan for technical support. M. Naveed is funded by the Biotechnology and Biological Sciences Research Council (BBSRC) project ‘Rhizosphere by Design’ (BB/L026058/1). Open access via Springer Compact Agreement

PY - 2017/12

Y1 - 2017/12

N2 - Background and Aim: Plant exudates greatly affect the physical behaviour of soil, but measurements of the impact of exudates on compression characteristics are missing. Our aim is to provide these data and explore how plant exudates may enhance the restructuring of compacted soils following cycles of wetting and drying.Methods: Two soils were amended with Chia (Salvia hispanica) seed exudate at 5 concentrations, compacted in cores to 200 kPa stress (equivalent to tractor stress), equilibrated to -50 kPa matric potential, and then compacted to 600 kPa (equivalent to axial root stress) followed by 3 cycles of wetting and drying and recompression to 600 kPa at -50 kPa matric potential. Penetration resistance (PR), compression index (CC) and pore characteristics were measured at various steps.Results: PR decreased and CC increased with increasing exudate concentration. At 600 kPa compression, 1.85 mg exudate g-1 soil increased CC from 0.37 to 0.43 for sandy loam soil and from 0.50 to 0.54 for clay loam soil. After 3 wetting-drying cycles the clay loam was more resillient than the sandy loam soil, with resilience increasing with greater exudate concentration. Root growth modelled on PR data suggested plant exudates significantly eased root elongation in soil.Conclusion: Plant exudates improve compression characteristics of soils, easing penetration and enhancing recovery of root induced soil compaction.

AB - Background and Aim: Plant exudates greatly affect the physical behaviour of soil, but measurements of the impact of exudates on compression characteristics are missing. Our aim is to provide these data and explore how plant exudates may enhance the restructuring of compacted soils following cycles of wetting and drying.Methods: Two soils were amended with Chia (Salvia hispanica) seed exudate at 5 concentrations, compacted in cores to 200 kPa stress (equivalent to tractor stress), equilibrated to -50 kPa matric potential, and then compacted to 600 kPa (equivalent to axial root stress) followed by 3 cycles of wetting and drying and recompression to 600 kPa at -50 kPa matric potential. Penetration resistance (PR), compression index (CC) and pore characteristics were measured at various steps.Results: PR decreased and CC increased with increasing exudate concentration. At 600 kPa compression, 1.85 mg exudate g-1 soil increased CC from 0.37 to 0.43 for sandy loam soil and from 0.50 to 0.54 for clay loam soil. After 3 wetting-drying cycles the clay loam was more resillient than the sandy loam soil, with resilience increasing with greater exudate concentration. Root growth modelled on PR data suggested plant exudates significantly eased root elongation in soil.Conclusion: Plant exudates improve compression characteristics of soils, easing penetration and enhancing recovery of root induced soil compaction.

KW - plant exudates

KW - void ratio

KW - cone penetration resistance

KW - compression index

KW - root growth modelling

U2 - 10.1007/s11104-017-3424-5

DO - 10.1007/s11104-017-3424-5

M3 - Article

SN - 0032-079X

VL - 421

SP - 19

EP - 30

JO - Plant and Soil

JF - Plant and Soil

IS - 1-2

ER -

Plant exudates improve the mechanical conditions for root penetration through compacted soils

Abstract

Bibliographical note

Keywords

Access to Document

Fingerprint

Profiles

Paul Hallett

Cite this