TY  - JOUR
AU  - Schröder, Natalie
AU  - Lazarovitch, Naftali
AU  - Vanderborght, Jan
AU  - Vereecken, Harry
AU  - Javaux, Mathieu
TI  - Linking transpiration reduction to rhizosphere salinity using a 3D coupled soil-plant model
JO  - Plant and soil
VL  - 377
IS  - 1-2
SN  - 1573-5036
CY  - Dordrecht [u.a.]
PB  - Springer Science + Business Media B.V
M1  - FZJ-2014-03048
SP  - 277 - 293
PY  - 2014
AB  - Aims: Soil salinity can cause salt plant stress by reducing plant transpiration and yield due to very low osmotic potentials in the soil. For predicting this reduction, we present a simulation study to (i) identify a suitable functional form of the transpiration reduction function and (ii) to explain the different shapes of empirically observed reduction functions.MethodsWe used high resolution simulations with a model that couples 3D water flow and salt transport in the soil towards individual roots with flow in the root system.ResultsThe simulations demonstrated that the local total water potential at the soil-root interface, i.e. the sum of the matric and osmotic potentials, is for a given root system, uniquely and piecewise linearly related to the transpiration rate. Using bulk total water potentials, i.e. spatially and temporally averaged potentials in the soil around roots, sigmoid relations were obtained. Unlike for the local potentials, the sigmoid relations were non-unique functions of the total bulk potential but depended on the contribution of the bulk osmotic potential.ConclusionsTo a large extent, Transpiration reduction is controlled by water potentials at the soil-root interface. Since spatial gradients in water potentials around roots are different for osmotic and matric potentials, depending on the root density and on soil hydraulic properties, transpiration reduction functions in terms of bulk water potentials cannot be transferred to other conditions, i.e. soil type, salt content, root density, beyond the conditions for which they were derived. Such a transfer could be achieved by downscaling to the soil-root interface using simulations with a high resolution process model.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000333614600019
DO  - DOI:10.1007/s11104-013-1990-8
UR  - https://juser.fz-juelich.de/record/153441
ER  -