Project Description

The rhizosphere, i.e. the zone of soil immediately surrounding plant roots, plays a prominent role in supplying plants with water and nutrients. However, surprisingly little is known about rhizosphere physical properties and how they affect root growth, water and nutrient uptake.

The lack of non-invasive and non-destructive imaging techniques necessary to observe living roots growing in undisturbed soil have been a main reason for this shortcoming. Recent advances in synchrotron X-ray microtomography (CMT) provide the potential to directly observe soil physical properties around living roots in-situ.

The goal of the proposed study is to quantify rhizosphere physical properties by:

1. employing CMT to visualize physical root-soil structure interactions,
2. simulating root-induced structural alterations using various micro-mechanical approaches (analytical, finite element, discrete element modeling), and
3. estimating changes in rhizosphere hydraulic properties (water retention and hydraulic conductivity functions) based on CMT imaging and inverse modeling.

The proposed study seeks to provide transformative insights into the role of rhizosphere physical properties for water and nutrient uptake by living plants. It serves as a stepping stone for better understanding the role of plants in the critical zone at the soil-atmosphere interface. The project cuts across disciplinary boundaries of biology, soil physics, and soil mechanics to offer new insights on surface runoff, soil compaction and erosion, losses to agricultural productivity, land reclamation, and first-principles of soil-plant interactions.

Video: Soil Structure and Plant Roots

8/31/2011: Dr. Markus Berli heads a research team using cutting-edge technology to study the impact soil structure has on a root system.