TRANSIENT STRUCTURE OF THE RHIZOSPHERE: IT FORMATION AND FUNCTION

The rhizosphere is the interface through which plants interact with the soil environment. All soil-derived plant resources must pass through this important interface that is a transition between the biotic realm of the root and biophysical realm of the soil. It is milieu of elevated biological activity and nutrient cycling. The rhizosphere provides these important functions because it acquires distinct characteristics as a direct consequence of resources pumped into it from roots and the accompanying biophysical processes. Here we present a mathematical model of the biophysical and biogeochemical processes of the rhizosphere, which are responsible for the development of distinct and stable soil structure. The model includes coupled interactions between root exudation, diffusion, microbial activity, and enhanced wetting drying cycles. These interactions give rise to transient hot spots of nutrient cycling and elevated nutrient and water delivery capability that allow plants to thrive in otherwise resource-limited environment. Aspects of the model are tested against quantitative and image data from literature.