Project
Synergistic mobilization of soil Fe by plant ligands and reductants
To cope with soil conditions of low Fe bioavailability, plant species have developed different strategies based on root exudation of either chelating ligands or reductants. Recent studies show that combining chelating ligands and reductants can more effectively (synergistically) mobilize Fe from soil, indicating the potential of intercropping for improving plant Fe uptake. This project seeks to develop a mechanistic understanding of the processes underlying this synergistic Fe mobilization, for application in developing more sustainable agricultural methods.
Background
To meet the needs of a growing world population while maintaining sustainability, agriculture needs to optimise nutrient utilisation from existing soil reservoirs. Fe is an essential nutrient for plant growth and development. Insufficient Fe uptake can result in decreased volume and nutritional value of crop yields. Major annual crops affected by Fe deficiency include rice, soybean, field bean, pea, lupin, corn and sorghum. Also many perennial fruit-bearing plants are highly susceptible. Fe deficiency in crops directly contributes to malnutrition in billions of people (e.g. anemia), particularly in developing countries.
The bioavailability of iron is constrained by the low solubility of iron oxide minerals. It is particularly poor in soils with a circumneutral pH which cover one third of the Earth's land surface. On such soils, Fe availability can strongly limit the crop yields. Therefore, this project focuses on plant Fe acquisition.
Description
This project aims to gain a quantitative and mechanistic understanding of the interactive processes between plant ligands and reductants and soil constituents that induce and constrain synergistic Fe mobilisation from soils. Also the effects of environmental conditions on these synergisms will be examined. Batch experiments will be conducted under controlled conditions to quantify sorption and dissolution processes in soil and mineral suspensions. The study will investigate the influence of soil properties and environmental conditions, including temperature, soil moisture content, soil organic matter (SOM), clay, and manganese (Mn-) and Fe-(hydr)oxide content, on synergistic Fe mobilisation. Furthermore, the project will also explore the mechanisms by which SOM and Mn-oxides impact synergistic Fe mobilisation. Additionally, the study will investigate the size and replenishment potential of the labile Fe pool susceptible to synergistic mobilisation by ligands and reductants.
Results
This project will give a mechanistic understanding and quantitative description of synergistic Fe mobilisation by combining the two plant Fe acquisition strategies. Furthermore, it will elucidate how soil properties and environmental variables affect synergistic Fe mobilisation quantitatively.