Hello,

Here is a postdoc announcement, on modelling soil-plante interactions
for water in South of France vineyards. Below a detailed decription of
this position. Best regards, F. Gerard

Context
The DISP?eau Project (2009-2012) is aimed at implementing a new decision
support system for vine growing based on precision irrigation. This R&D
project is headed up by ITK (http://www.itkweb.com/) and brings together
10 French partners (3 performing R&D SMEs, 3 research centres, 3
associations and 1 institutional organization). It is co-funded by the
European Commission through the European Regional Development Fund
(ERDF) in the Languedoc-Roussillon region (France) and the French
National Innovation Fund.

Under the supervision of a research fellow leading the soil modelling
research at the Eco&Sols research unit (involving INRA, IRD, Montpellier
Supagro, and CIRAD) and the Project manager of the DISP?eau project, and
in close collaboration with other qualified staff, the successful
applicant will contribute to the elaboration of a numerical model
coupling soil hydrology and vineyard root water uptake mechanisms.

The validation of the model will be done using /in situ/ measurements
realized on 6 intensively instrumented sites located in the
Languedoc-Roussillon region and supervised by the UPR80 research unit of
the CIRAD (http://www.cirad.fr/ur/ecosystemes_plantations). In this
region, respected and established quality wines and grape varieties
(carignan, grenache, syrah, grenache blanc, etc.) are produced. The main
experimental fields are located at sites belonging to the French
National Institute for Agricultural Research (INRA) and to two of the
biggest wine cooperatives of the Languedoc-Roussillon region.

Description
The postdoctoral fellow will be in charge of developing a global
Soil-Vine water transfer model using an innovating 3D Soil model (Kamel)
that takes into account the hierarchical and aggregated soil structure
and its interaction with water at the micro and macro scales, and a 3D
root model that characterizes the morphological behaviour and dynamics
of the vine root system. The postdoctoral fellow will contribute to
research that will certainly result in papers publishable in high
quality journals.

Specific tasks
1- Adapt an existing root model to the structure and dynamics of the
vine root system, in collaboration with a researcher of the UPR80 of the
CIRAD who supervises the experimentation.
2- Define the soil model boundary conditions related to vineyard
situations and compare the water transfers in the vadose zone simulated
by Kamel to those simulated by the MIN3P model, which uses the standard
approach for water flow modelling based on the definition of
Representative Elementary Volumes wherein soil properties are considered
homogeneous. This part of the work will be accomplished in partnership
with Eco&Sols
(http://www.montpellier.inra.fr/centre_et_unites/unites_et_campus/les_unites_du_centre/eco_sols
)
3- Evaluate the interactions between the root system and the soil
structure and define the appropriate functions in the developed model.
4- Validate results with /in situ/ measurements

*Required qualifications:*

- Ph.D in hydrology, computational fluid dynamics, environmental
sciences, or applied mathematics

- Extensive experience in complex mathematical modelling and numerical
methods

- Matlab and/or Java programming,

- Outstanding scientific analysis skills.

- Ability and interests to work with researchers from other fields and
backgrounds.

- Excellent communication skills both oral and written, (English or French).

Duration
The project will start in September 2010 for 1 year with a possible
extension for two years after evaluation by a project committee.
The position term can be extended according to applicant interest with a
work consisting in coupling a structured and dynamic canopy model to the
complex soil model achieved, and coupling a module that permits to take
into account water stress effect on stomatal activity and canopy growth.
This work will contribute to the definition of an expert system for vine
trellising and will be done in partnership with the LEPSE laboratory
(http://www1.montpellier.inra.fr/ibip/lepse/) involving CNRS, INRA,
SupAgro and Montpellier University.

Working place: ITK, Montpellier, France.

Salary: 27 Keuro/year gross wage

Contact (send CV and motivation letter):

Valérie Auffray ([log in to unmask]
<mailto:[log in to unmask]>)

Frédéric Gérard ([log in to unmask]
<mailto:[log in to unmask]>)

Bibliography
1) Braudeau, E. & Mohtar, R.H. 2008. Modeling the Soil System: Bridging
the Gap Between Pedology and Soil-Water Physics. Global and Planetary
Change Journal, Special issue.

2) Braudeau, E., Mohtar, R. H., El Ghezal, N., Crayol, M., Salahat M.,
Clouvel, P., Jallas, E. and Martin, P., 2008. Modeling and
Characterizing Soil Hydrostructural Properties: Kamel and KamelSoil.
Journal of Hydrology Engineering. (in review)

3) Gérard F., Tinsley M., and Mayer K. U. (2004) Preferential flow
revealed by hydrologic modeling based on predicted hydraulic properties.
/Soil Sci. Soc. Am. J. /68, 1526-1538.

4) Jourdan C, Rey H. 1997a. Architecture and development of the oil-palm
(Elaeis guineensis Jacq.) root system. Plant Soil 189:33 ? 48.

5) Jourdan C, Rey H. 1997b. Modelling and simulation of the architecture
and development of the oil-palm (Elaeis guineensis Jacq.) root system.
I. The model. Plant Soil 190:217 ? 233.

6) Jourdan C, Rey H. 1997c. Modelling and simulation of the architecture
and development of the oil-palm (Elaeis guineensis Jacq.) root system.
II. Estimation of root parameters using the RACINES postprocessor. Plant
Soil 190:235 ? 246.

7) Louarn G, Lecoeur J, Lebon E. 2008a. A 3D reconstruction model of
grapevine (Vitis vinifera L.) simulating canopy structure variability
within and between cultivars/training system pairs. /Annals of Botany/
101: 1167-1184.

8) Louarn G, Dauzat J, Lecoeur J, Lebon E. 2008b Influence of Trellis
system and shoot positioning on light interception and distribution in
two grapevine cultivars with different architectures- an original
approach based on 3D canopy modelling. /Australian Journal of Grape and
Wine Research/ 14:143-152

9) Puigt G., Auffray V. and Muller J-D. Discretisation of diffusive
fluxes on hybrid grids. Journal of Computational Physics 229 (2010)
1425?1447.

----------------------------------------------------------------
This message was sent using IMP, the Internet Messaging Program.