Mathematics and Rhizotechnology. Mathematical methods for upscaling of rhizosphere control mechanisms.
Abstract
In areas such as physics, the role of mathematics in the development of new techniques is beyond dispute. Mechanistic mathematical models and computer simulation will also advance the development of rhizotechnologies. The development of such models is the main objective of this project. The rhizosphere is the soil volume influenced by root activities, characterised by multiple interactions between the roots, soil micro-organisms and physical processes. Rhizotechnologies for crop management take advantage of these processes by direct or indirect manipulation of one or more components of the system. Our main hypothesis is that rhizosphere processes considered important on the single root scale may be amplified or diminished on the whole root system or field scale. We are going to assess this using mathematical modelling and then confirm our findings experimentally. For example, the effect of root exudates on phosphorus nutrient efficiency has been studied only on the single root scale. However, the “real” effect on the root system level may be over- or underestimated if one does not use rigorous mathematical modelling to do the upscaling. Thus, to analyse the effect of many individual rhizospheres on the whole root system and field scale, it is necessary to employ and develop rigorous mathematical upscaling techniques such as averaging and homogenisation. In this project, two exemplary rhizosphere features, root architecture and root exudation, and their effects on phosphorus efficiency of oil seed rape will be considered in order to develop the mathematical model. Related experimental investigations will support model development and parameterisation. The simulation tool will be designed in such a way that other characteristics (e.g. root hairs and/or mycorrhizal fungi) can be added. This will allow for modelling the effect of multiple rhizosphere processes on nutrient efficiency; therefore allow us to model real-world situations which would be very expensive and time consuming to do experimentally. We will develop a mechanistic mathematical model that describes the dynamics caused by one single root and its rhizosphere in soil. The mathematical method for upscaling from single root to whole root system and field scale developed by Roose and Fowler (2004) will be applied and adapted in this project in order to assess single root scale effects on phosphorus efficiency of oil seed rape. On all scales, the model will be analysed using the methods of nondimensionalisation and asymptotic expansion complemented by numerical analysis using the software packages COMSOL and Matlab. The model will be calibrated and validated against data measured in independent experiments. Sensitivity analysis will be performed to determine the processes at all scales that dominate the outcome of the model. The experimental approaches include the selection of oil seed rape cultivars with differing exudation pattern, root architecture and root branching structure, determination of phosphorus exudate interactions and assessment of the effect of exudation and root architecture on plant phosphorus efficiency. The close collaboration between modellers and experimentalists working in the same organisation as well as the possibility to gain know-how and experiences from international collaboration facilitates a true interdisciplinary approach, bridging rhizosphere research and mathematics not only across Austria, but also across the several EU countries. This provides the optimal environment for model adaptations, revision of model assumptions, and testing of new hypotheses. This procedure will deepen our insight into the underlying processes, and will lead to optimised performance of rhizotechnologies, resulting in higher production efficiency, and reduction of both experimental costs and environmental load. This project is significant due to the novelty of the modelling approach and the expected scientific breakthrough in the area of rhizotechnologies.
Publikationen
Measuring soil solution phosphorus depletion in the rhizosphere of Brassica napus at very high resolution using DGT
Autoren: Santner, J., Zhang, H., Prohaska, T., Puschenreiter, M., Wenzel, W. W. Jahr: 2009
Conference & Workshop proceedings, paper, abstract
High resolution determination of soil solution P concentrations in the vicinity of Brassica napus L. roots
Autoren: Santner, J., Zhang, H., Davison, W., Puschenreiter, M., Wenzel, W.W. Jahr: 2009
Conference & Workshop proceedings, paper, abstract
FEM simulation of below ground processes on a 3-dimensional root system geometry using DISTMESH and COMSOL Multiphysics
Autoren: A. Schnepf and D.Leitner Jahr: 2009
Conference & Workshop proceedings, paper, abstract
Ferrihydrite Containing Gel for Chemical Imaging of Labile Phosphate Species in Sediments and Soils Using Diffusive Gradients in Thin Films
Autoren: Santner, J; Prohaska, T; Luo, J; Zhang, H Jahr: 2010
Journal articles
Chemical imaging of dissolved phosphorus reveals complex P dynamics in the rhizosphere of Brassica napus
Autoren: Santner, J.,Zhang, H., Leitner, D., Prohaska, T., Puschenreiter, M., Wenzel W. W. Jahr: 2010
Conference & Workshop proceedings, paper, abstract
High-resolution chemical imaging of labile phosphorus in the rhizosphere of Brassica napus L. cultivars
Autoren: Santner, J; Zhang, H; Leitner, D; Schnepf, A; Prohaska, T; Puschenreiter, M; Wenzel, WW Jahr: 2012
Journal articles
First observation of diffusion-limited plant root phosphorus uptake from nutrient solution.
Autoren: Santner, J; Smolders, E; Wenzel, WW; Degryse, F; Jahr: 2012
Journal articles
Project staff
Andrea Schnepf
Priv.-Doz. Dipl.-Ing. Dr.nat.techn. Andrea Schnepf MSc.
andrea.schnepf@boku.ac.at
Project Leader
01.03.2008 - 31.05.2011
Johannes Daniel Leitner
Priv.-Doz. Dr. Johannes Daniel Leitner
Project Staff
01.03.2008 - 31.05.2011
Willibald Loiskandl
Univ.-Prof. i.R. Dipl.-Ing. Dr.nat.techn. Willibald Loiskandl
willibald.loiskandl@boku.ac.at
Project Staff
01.03.2008 - 31.05.2011
Markus Puschenreiter
Priv.-Doz. Dr. Markus Puschenreiter
markus.puschenreiter@boku.ac.at
Tel: +43 1 47654-91143, 91163
Project Staff
01.03.2008 - 31.05.2011
Jakob Santner
Priv.-Doz. Dipl.-Ing. Dr.nat.techn. Jakob Santner
jakob.santner@boku.ac.at
Project Staff
01.03.2008 - 31.05.2011
Walter Wenzel
Univ.Prof. Dipl.-Ing. Dr.nat.techn. Walter Wenzel
walter.wenzel@boku.ac.at
Tel: +43 1 47654-91143, 91161
Project Staff
01.03.2008 - 31.05.2011
BOKU partners
External partners
Vienna University of Technology, Faculty of Mathematics and Geoinformation, Institute of Analysis and Scientific Computing
Ao.Univ.Prof. DI DDDr. Frank Rattay
partner
University of Oxford, Oxford Centre for Industrial and Applied Mathematics and Centre for Mathematical Biology, Mathematical Institute
Dr. Tiina Roose
partner