Three-dimensional visualization and quantification of water content in the rhizosphere
Article first published online: 8 AUG 2011
© 2011 The Authors. New Phytologist © 2011 New Phytologist Trust
Volume 192, Issue 3, pages 653–663, November 2011
How to Cite
Moradi, A. B., Carminati, A., Vetterlein, D., Vontobel, P., Lehmann, E., Weller, U., Hopmans, J. W., Vogel, H.-J. and Oswald, S. E. (2011), Three-dimensional visualization and quantification of water content in the rhizosphere. New Phytologist, 192: 653–663. doi: 10.1111/j.1469-8137.2011.03826.x
- Issue published online: 19 OCT 2011
- Article first published online: 8 AUG 2011
- Received: 2 June 2011, Accepted: 10 June 2011
- extent of rhizosphere;
- neutron tomography;
- rhizosphere hydraulic properties;
- root water uptake;
- soil moisture profile;
- water distribution
- •Despite the importance of rhizosphere properties for water flow from soil to roots, there is limited quantitative information on the distribution of water in the rhizosphere of plants.
- •Here, we used neutron tomography to quantify and visualize the water content in the rhizosphere of the plant species chickpea (Cicer arietinum), white lupin (Lupinus albus), and maize (Zea mays) 12 d after planting.
- •We clearly observed increasing soil water contents (θ) towards the root surface for all three plant species, as opposed to the usual assumption of decreasing water content. This was true for tap roots and lateral roots of both upper and lower parts of the root system. Furthermore, water gradients around the lower part of the roots were smaller and extended further into bulk soil compared with the upper part, where the gradients in water content were steeper.
- •Incorporating the hydraulic conductivity and water retention parameters of the rhizosphere into our model, we could simulate the gradual changes of θ towards the root surface, in agreement with the observations. The modelling result suggests that roots in their rhizosphere may modify the hydraulic properties of soil in a way that improves uptake under dry conditions.