Soil compaction-N interactions in barley: root growth and tissue composition

IJ Bingham, AG Bengough, RM Rees

Research output: Contribution to journalArticleResearchpeer-review

24 Citations (Scopus)

Abstract

A controlled environment study investigated the interactions between soil compaction and N availability on the growth and root tissue composition of young barley plants. Plants were grown for 14 days in a mixture of sand and calcined clay (fired clay granules) at two levels of compaction (low and high; dry bulk densities of 0.94 and 1.08 g cm 3 respectively) and two levels of N supply (high, resulting in N sufficient plants and low giving plants deficient in N). High compaction reduced total root length by 23%, leaf area by 21% and altered biomass partitioning (reduced leaf area ratio and increased root weight ratio), but had no effect on total biomass production over the time-course of the experiment. By contrast low N supply, reduced root biomass by 42% and shoot biomass by 47%, but had less effect on shoot morphology than compaction. There was no significant interaction between compaction and N supply on growth and biomass partitioning, although towards the end of the experiment, the rate of N uptake per unit root dry weight was reduced by about 50% by high compaction when N supplies were low, but not when they were high. Compaction altered the concentration of some root tissue components independently of N supply. For example, high compaction reduced the concentration of cellulose plus hemi-cellulose by 30% and increased the mineral content by 38%, whilst N supply had no effect. The concentration of several other components was altered by compaction and N supply in the same direction. Both high compaction and low N supply increased the lignin concentrationwhilst reducing the concentration of organic N compounds and nitrate, thereby increasing the C:N and lignin:N ratios. Compaction and low N supply increased C:N by a factor of 1.3 and 1.8 respectively, whilst the lignin:N ratio was increased by 1.7 and 2.1 respectively. Thus, both compaction and lowN availability altered root tissue composition in a way that might reduce the rate of root degradation by soil microbes. The implications of these findings for modelling nutrient cycling are briefly discussed. 2009 Elsevier B.V. All rights reserved.
Original languageEnglish
Pages (from-to)241 - 246
Number of pages6
JournalSoil and Tillage Research
Volume106
Publication statusFirst published - 2010

Fingerprint

soil compaction
root growth
barley
lignin
biomass
cellulose
leaf area
clay
tissues
soil microorganisms
biogeochemical cycles
mineral content
bulk density
granules
biomass production
nitrates
sand
uptake mechanisms
shoots
degradation

Bibliographical note

607006

Keywords

  • Barley
  • Carbon
  • Nitrogen
  • Nutrient cycling
  • Root decomposition
  • Soil compaction

Cite this

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title = "Soil compaction-N interactions in barley: root growth and tissue composition",
abstract = "A controlled environment study investigated the interactions between soil compaction and N availability on the growth and root tissue composition of young barley plants. Plants were grown for 14 days in a mixture of sand and calcined clay (fired clay granules) at two levels of compaction (low and high; dry bulk densities of 0.94 and 1.08 g cm 3 respectively) and two levels of N supply (high, resulting in N sufficient plants and low giving plants deficient in N). High compaction reduced total root length by 23{\%}, leaf area by 21{\%} and altered biomass partitioning (reduced leaf area ratio and increased root weight ratio), but had no effect on total biomass production over the time-course of the experiment. By contrast low N supply, reduced root biomass by 42{\%} and shoot biomass by 47{\%}, but had less effect on shoot morphology than compaction. There was no significant interaction between compaction and N supply on growth and biomass partitioning, although towards the end of the experiment, the rate of N uptake per unit root dry weight was reduced by about 50{\%} by high compaction when N supplies were low, but not when they were high. Compaction altered the concentration of some root tissue components independently of N supply. For example, high compaction reduced the concentration of cellulose plus hemi-cellulose by 30{\%} and increased the mineral content by 38{\%}, whilst N supply had no effect. The concentration of several other components was altered by compaction and N supply in the same direction. Both high compaction and low N supply increased the lignin concentrationwhilst reducing the concentration of organic N compounds and nitrate, thereby increasing the C:N and lignin:N ratios. Compaction and low N supply increased C:N by a factor of 1.3 and 1.8 respectively, whilst the lignin:N ratio was increased by 1.7 and 2.1 respectively. Thus, both compaction and lowN availability altered root tissue composition in a way that might reduce the rate of root degradation by soil microbes. The implications of these findings for modelling nutrient cycling are briefly discussed. 2009 Elsevier B.V. All rights reserved.",
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Soil compaction-N interactions in barley: root growth and tissue composition. / Bingham, IJ; Bengough, AG; Rees, RM.

In: Soil and Tillage Research, Vol. 106, 2010, p. 241 - 246.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Soil compaction-N interactions in barley: root growth and tissue composition

AU - Bingham, IJ

AU - Bengough, AG

AU - Rees, RM

N1 - 607006

PY - 2010

Y1 - 2010

N2 - A controlled environment study investigated the interactions between soil compaction and N availability on the growth and root tissue composition of young barley plants. Plants were grown for 14 days in a mixture of sand and calcined clay (fired clay granules) at two levels of compaction (low and high; dry bulk densities of 0.94 and 1.08 g cm 3 respectively) and two levels of N supply (high, resulting in N sufficient plants and low giving plants deficient in N). High compaction reduced total root length by 23%, leaf area by 21% and altered biomass partitioning (reduced leaf area ratio and increased root weight ratio), but had no effect on total biomass production over the time-course of the experiment. By contrast low N supply, reduced root biomass by 42% and shoot biomass by 47%, but had less effect on shoot morphology than compaction. There was no significant interaction between compaction and N supply on growth and biomass partitioning, although towards the end of the experiment, the rate of N uptake per unit root dry weight was reduced by about 50% by high compaction when N supplies were low, but not when they were high. Compaction altered the concentration of some root tissue components independently of N supply. For example, high compaction reduced the concentration of cellulose plus hemi-cellulose by 30% and increased the mineral content by 38%, whilst N supply had no effect. The concentration of several other components was altered by compaction and N supply in the same direction. Both high compaction and low N supply increased the lignin concentrationwhilst reducing the concentration of organic N compounds and nitrate, thereby increasing the C:N and lignin:N ratios. Compaction and low N supply increased C:N by a factor of 1.3 and 1.8 respectively, whilst the lignin:N ratio was increased by 1.7 and 2.1 respectively. Thus, both compaction and lowN availability altered root tissue composition in a way that might reduce the rate of root degradation by soil microbes. The implications of these findings for modelling nutrient cycling are briefly discussed. 2009 Elsevier B.V. All rights reserved.

AB - A controlled environment study investigated the interactions between soil compaction and N availability on the growth and root tissue composition of young barley plants. Plants were grown for 14 days in a mixture of sand and calcined clay (fired clay granules) at two levels of compaction (low and high; dry bulk densities of 0.94 and 1.08 g cm 3 respectively) and two levels of N supply (high, resulting in N sufficient plants and low giving plants deficient in N). High compaction reduced total root length by 23%, leaf area by 21% and altered biomass partitioning (reduced leaf area ratio and increased root weight ratio), but had no effect on total biomass production over the time-course of the experiment. By contrast low N supply, reduced root biomass by 42% and shoot biomass by 47%, but had less effect on shoot morphology than compaction. There was no significant interaction between compaction and N supply on growth and biomass partitioning, although towards the end of the experiment, the rate of N uptake per unit root dry weight was reduced by about 50% by high compaction when N supplies were low, but not when they were high. Compaction altered the concentration of some root tissue components independently of N supply. For example, high compaction reduced the concentration of cellulose plus hemi-cellulose by 30% and increased the mineral content by 38%, whilst N supply had no effect. The concentration of several other components was altered by compaction and N supply in the same direction. Both high compaction and low N supply increased the lignin concentrationwhilst reducing the concentration of organic N compounds and nitrate, thereby increasing the C:N and lignin:N ratios. Compaction and low N supply increased C:N by a factor of 1.3 and 1.8 respectively, whilst the lignin:N ratio was increased by 1.7 and 2.1 respectively. Thus, both compaction and lowN availability altered root tissue composition in a way that might reduce the rate of root degradation by soil microbes. The implications of these findings for modelling nutrient cycling are briefly discussed. 2009 Elsevier B.V. All rights reserved.

KW - Barley

KW - Carbon

KW - Nitrogen

KW - Nutrient cycling

KW - Root decomposition

KW - Soil compaction

M3 - Article

VL - 106

SP - 241

EP - 246

JO - Soil and Tillage Research

JF - Soil and Tillage Research

SN - 0167-1987

ER -