Project

Micronutrient acquisition in extreme environments: the sodic soils of the Neusiedler See (AT)

Sodic soils are extreme environments with very high pH values (> 9) and salt concentrations, creating a niche for organisms that can survive under such conditions. The availability of cationic micronutrients like Fe, Cu, Zn and Mn, is very low at such high pH values.

Background

An important class of micronutrient acquisition strategies of plants and microorganisms is based on the exudation of chelating ligands that form soluble complexes with metal cations, facilitating their transport towards and uptake by the exuding organism. Yet, little is known about the effectiveness of these micronutrient acquisition strategies under sodic soil conditions.

In this MSc thesis project this knowledge gap will be addressed by examining the bioavailability of micronutrients in sodic soils from the Neusiedler See area in Austria. Multi-surface models will be composed for a series of these sodic soils to predict the free metal concentrations of micronutrients as a measure for their bioavailability. The models will then be used for predicting the effect of chelating ligands exuded by plants and microorganisms for micronutrient acquisition on the speciation of Fe, Cu, Zn and Mn. Based on the model predictions, a subset of soils will be selected for kinetic batch experiments. In these experiments solutions containing the same chelating ligands that were included into the models will be added to the sodic soils. Micronutrient mobilization from the soils will be analysed and provide insight in the effectiveness of nutrient acquisitions strategies based ion chelating ligands in sodic soils. Results from these experiments will contribute to a better understanding of how organisms can survive under such harsh conditions.

Used skills

  • Literature review;
  • Proposal writing;
  • Multi-surface modelling;
  • Laboratory (soil extractions, kinetic batch experiments);
  • Data processing;
  • Thesis writing.

Requirements

  • Some laboratory experience is required;
  • The required courses for:
    • MSc thesis Soil Chemistry and Chemical Soil Quality (SOC-81336);
    • Chemical Processes in Soil, Water and Atmosphere (SOC22306);
    • and preferably including Soil Quality (SOC21806)