Study on linking rhizosphere processes across scales

Simultaneously interacting rhizosphere processes determine emergent plant behaviour, including growth, transpiration, nutrient uptake, soil carbon storage and transformation by microorganisms. However, these processes occur on multiple scales, challenging modelling of rhizosphere and plant behaviour. Current advances in modelling and experimental methods open the path to unravel the importance and interconnectedness of those processes across scales. In a recent publication, Schnepf et al. (2022) present a series of case studies of state-of-the art simulations addressing this multiscale, multi-process problem from a modelling point of view, as well as from the point of view of integrating newly available rhizosphere data and images. The case studies include image-based modelling, pore-scale modelling, continuum scale modelling, and functional-structural plant modelling and demonstrate how to link the pore scale to the continuum scale by homogenisation or by deriving effective physical parameters like viscosity from nanoscale chemical properties. Modelling allows to integrate new experimental data across different rhizosphere processes and scales as exemplified for root rhizodeposition, plant nutrient uptake and soil microbial activity. Described models are tools to test hypotheses and consequently improve our mechanistic understanding of how rhizosphere processes impact plant-scale behaviour. Linking multiple scales and processes including the dynamics of root growth is the logical next step for future research.

A. Schnepf, A. Carminati, M.A. Ahmed, M. Ani, P. Benard, J. Bentz, M. Bonkowski, M. Knott, D. Diehl, P. Duddek, E. Kröner, M. Javaux, M. Landl, E. Lehndorff, E. Lippold, A. Lieu, C. W. Mueller, E. Oburger, W. Otten, X. Portell, M. Phalempin, A. Prechtel, R. Schulz, J. Vanderborght & D. Vetterlein (2022): Linking rhizosphere processes across scales: Opinion. Plant and Soil. https://doi.org/10.1007/s11104-022-05306-7