Advanced

Organic acid behaviour in a calcareous soil implications for rhizosphere nutrient cycling

Ström, Lena LU ; Owen, AG; Godbold, DL and Jones, DL (2005) In Soil Biology & Biochemistry 37(11). p.2046-2054
Abstract
Calcareous soils are frequently characterized by the low bioavailability of plant nutrients. Consequently, many vascular plant species are unable to successfully colonize calcareous sites and the floristic composition of calcareous and acid silicate soils has been shown to differ markedly. The root exudation of oxalate and citrate has been suggested to play a pivotal role in same nutrient acquisition mechanisms operating in calcareous soils. The aim of this study was therefore to investigate the nutrient extraction efficiency of three individual organic acids commonly identified in root exudates, i.e. citric, malic and oxalic acid. Our results clearly demonstrate the context dependent nature of nutrient release by organic acids. The degree... (More)
Calcareous soils are frequently characterized by the low bioavailability of plant nutrients. Consequently, many vascular plant species are unable to successfully colonize calcareous sites and the floristic composition of calcareous and acid silicate soils has been shown to differ markedly. The root exudation of oxalate and citrate has been suggested to play a pivotal role in same nutrient acquisition mechanisms operating in calcareous soils. The aim of this study was therefore to investigate the nutrient extraction efficiency of three individual organic acids commonly identified in root exudates, i.e. citric, malic and oxalic acid. Our results clearly demonstrate the context dependent nature of nutrient release by organic acids. The degree of P extraction was highly dependent on which organic acid was added, their concentration and pH, and their contact time with the soil. P is generally more efficiently extracted by organic acids at a high pH and follows the series oxalate > citrate > malate. The opposite relationship between pH and extraction efficiency was apparent for most other cations examined (e.g. Zn, Fe), which are more efficiently extracted by organic acids at low pH. A serious constraint to the ecological importance of organic acid exudation in response to P deficiency is, however, their very low P mobilization efficiency. For every mol of soil P mobilized, 1000 mol of organic acid has to be added. It can, however, be speculated that in a calcareous soil with extremely low P concentrations it is still beneficial to the plants to exude organic acids in spite of the seemingly high costs in terms of carbon. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
calcareous soil, malate, organic acids, oxalate, rendzina, root, phosphorus, citrate
in
Soil Biology & Biochemistry
volume
37
issue
11
pages
2046 - 2054
publisher
Elsevier
external identifiers
  • wos:000233501100008
  • scopus:27444442325
ISSN
0038-0717
DOI
10.1016/j.soilbio.2005.03.009
language
English
LU publication?
yes
id
1e65adec-41c7-4a44-a37a-c62ffa6ce679 (old id 211966)
date added to LUP
2007-08-21 09:26:09
date last changed
2017-10-01 04:53:43
@article{1e65adec-41c7-4a44-a37a-c62ffa6ce679,
  abstract     = {Calcareous soils are frequently characterized by the low bioavailability of plant nutrients. Consequently, many vascular plant species are unable to successfully colonize calcareous sites and the floristic composition of calcareous and acid silicate soils has been shown to differ markedly. The root exudation of oxalate and citrate has been suggested to play a pivotal role in same nutrient acquisition mechanisms operating in calcareous soils. The aim of this study was therefore to investigate the nutrient extraction efficiency of three individual organic acids commonly identified in root exudates, i.e. citric, malic and oxalic acid. Our results clearly demonstrate the context dependent nature of nutrient release by organic acids. The degree of P extraction was highly dependent on which organic acid was added, their concentration and pH, and their contact time with the soil. P is generally more efficiently extracted by organic acids at a high pH and follows the series oxalate > citrate > malate. The opposite relationship between pH and extraction efficiency was apparent for most other cations examined (e.g. Zn, Fe), which are more efficiently extracted by organic acids at low pH. A serious constraint to the ecological importance of organic acid exudation in response to P deficiency is, however, their very low P mobilization efficiency. For every mol of soil P mobilized, 1000 mol of organic acid has to be added. It can, however, be speculated that in a calcareous soil with extremely low P concentrations it is still beneficial to the plants to exude organic acids in spite of the seemingly high costs in terms of carbon.},
  author       = {Ström, Lena and Owen, AG and Godbold, DL and Jones, DL},
  issn         = {0038-0717},
  keyword      = {calcareous soil,malate,organic acids,oxalate,rendzina,root,phosphorus,citrate},
  language     = {eng},
  number       = {11},
  pages        = {2046--2054},
  publisher    = {Elsevier},
  series       = {Soil Biology & Biochemistry},
  title        = {Organic acid behaviour in a calcareous soil implications for rhizosphere nutrient cycling},
  url          = {http://dx.doi.org/10.1016/j.soilbio.2005.03.009},
  volume       = {37},
  year         = {2005},
}