Comparisons of two root water uptake models based on field observations
(2015) Rhizosphere 4 — Location: Maastricht, Netherlands (22.June.2015)
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- Abstract
- Accurate estimation of water requirements and efficient water management of crops requires appropriate mathematic descriptions of water flow. Modeling root water uptake is an important approach to evaluate water movement in the soil-root system. However, dynamic root distribution and a physically based concept to describe water uptake from soil profiles with vertical variations in soil water availability are often not taken into consideration. Therefore, we incorporated observations of soil moisture and root development within two different modeling frameworks and compared the simulated root water uptake. To do so, we carried out field experiments where soil water content, soil water potential, and root growth were monitored non-invasively for three water treatments: sheltered, rain-fed, and irrigated. Root growth of winter wheat was measured by using 7-m long horizontally installed minirhizotubes at six depths with three replicates per treatment. The observed data were interpreted by Feddes model and an upscaled model based on hydraulic architecture approach (Couvreur et al., 2012) that considers compensatory root water uptake and hydraulic conductance in the coupled soil root system. Results showed that root water uptake simulated by Feddes model was affected by root distributions, whereas it was influenced by the conductance of the root system when using upscaled model with the same soil hydraulic properties and boundary conditions. Moreover, root water uptake simulated by the two models tended to deviate in dry and wet conditions due to different water stress functions. The upscaled model showed a promising optional approach for simulations of root water uptake by using 1-D spatial discretization to represent soil water dynamics in soil root system. To validate simulated root water uptake by these models, additional measurements, such as sap flow, might be helpful for the predictions of water requirement of different crops. Couvreur, V., Vanderborght, J., and Javaux, M.: A simple three dimensional macroscopic root water uptake model based on the hydraulic architecture approach, Hydrol. Earth Syst. Sci., 16, 2957–2971, doi:10.5194/hess-16-2957-2012, 2012.
- Affiliations
ForschungsZentrum Juelich Agrosphere Institute
Citations
Cai, G., Vanderborght, J., Couvreur, V., Mboh, C. M., Javaux, M., & Vereecken, H. (2015). Comparisons of two root water uptake models based on field observations. Rhizosphere 4, Maastricht, Netherlands. https://hdl.handle.net/2078.5/251366