Metal mobilization from soils by phytosiderophores - experiment and equilibrium modeling

Author(s)
Walter Schenkeveld, Eva Oburger, Barbara Gruber, Yvonne Schindlegger, Stephan Hann, Markus Puschenreiter, Stephan Krämer
Abstract

Aims: To test if multi–surface models can provide a soil-specific prediction of metal mobilization by phytosiderophores (PS) based on the characteristics of individual soils.

Methods: Mechanistic multi-surface chemical equilibrium modeling was applied for obtaining soil-specific predictions of metal and PS speciation upon interaction of the PS 2’-deoxymugineic acid (DMA) with 6 soils differing in availability of Fe and other metals. Results from multi-surface modeling were compared with empirical data from soil interaction experiments.

Results: For soils in which equilibrium was reached during the interaction experiment, multi-surface models could well predict PS equilibrium speciation. However, in uncontaminated calcareous soils, equilibrium was not reached within a week, and experimental and modeled DMA speciation differed considerably. In soils with circum-neutral pH, on which Fe deficiency is likely to occur, no substantial Fe mobilization by DMA was predicted. However, in all but the contaminated soils, Fe mobilization by DMA was observed experimentally. Cu and Ni were the quantitatively most important metals competing with Fe for complexation and mobilization by DMA.

Conclusion: Thermodynamics are unable to explain the role of PS as Fe carrier in calcareous soils, and the kinetic aspects of metal mobilization by PS need to be closer examined in order to understand the mechanisms underlying strategy II Fe acquisition.

Organisation(s)
External organisation(s)
University of Natural Resources and Life Sciences, acib – Austrian Centre of Industrial Biotechnology
Journal
Plant and Soil: international journal on plant-soil relationships
Volume
383
Pages
59-71
No. of pages
13
ISSN
0032-079X
DOI
https://doi.org/10.1007/s11104-014-2128-3
Publication date
2014
Peer reviewed
Yes
Austrian Fields of Science 2012
104004 Chemical biology, 105906 Environmental geosciences
Keywords
ASJC Scopus subject areas
Soil Science, Plant Science
Portal url
https://ucrisportal.univie.ac.at/en/publications/a6e94494-09aa-443e-be63-cf28ec6970ca