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| Titel |
Assessing HYDRUS-2D model to estimate soil water contents and olive tree transpiration fluxes under different water distribution systems |
| VerfasserIn |
Dario Autovino, Amro Negm, Giovanni Rallo, Giuseppe Provenzano |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250122280
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| Publikation (Nr.) |
 EGU/EGU2016-1276.pdf |
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| Zusammenfassung |
| In Mediterranean countries characterized by limited water resources for agricultural and
societal sectors, irrigation management plays a major role to improve water use efficiency at
farm scale, mainly where irrigation systems are correctly designed to guarantee a
suitable application efficiency and the uniform water distribution throughout the
field.
In the last two decades, physically-based agro-hydrological models have been developed
to simulate mass and energy exchange processes in the soil-plant-atmosphere (SPA) system.
Mechanistic models like HYDRUS 2D/3D (Šimunek et al., 2011) have been proposed to
simulate all the components of water balance, including actual crop transpiration fluxes
estimated according to a soil potential-dependent sink term. Even though the suitability of
these models to simulate the temporal dynamics of soil and crop water status has been
reported in the literature for different horticultural crops, a few researches have been
considering arboreal crops where the higher gradients of root water uptake are the
combination between the localized irrigation supply and the three dimensional root system
distribution.
The main objective of the paper was to assess the performance of HYDRUS-2D model to
evaluate soil water contents and transpiration fluxes of an olive orchard irrigated with two
different water distribution systems.
Experiments were carried out in Castelvetrano (Sicily) during irrigation seasons 2011 and
2012, in a commercial farm specialized in the production of table olives (Olea europaea L.,
var. Nocellara del Belice), representing the typical variety of the surrounding area. During the
first season, irrigation water was provided by a single lateral placed along the plant row with
four emitters per plant (ordinary irrigation), whereas during the second season a grid of
emitters laid on the soil was installed in order to irrigate the whole soil surface around the
selected trees.
The model performance was assessed based on the comparison between measured and
simulated soil water content and actual transpiration fluxes, under the hypothesis to neglect
the contribute of the tree capacitance. Moreover, two different crop water stress functions and
in particular the linear model proposed by Feddes et al. (1978) and the S-shape model
suggested by van Genuchten et al. (1987), were considered.
The result of the study evidenced that for the investigated crop and under the examined
conditions, HYDRUS-2D model reproduces fairly well the dynamic of soil water contents at
different distances from the emitters (RMSE<0.09 cm3 cm−3) and actual crop transpiration
fluxes (RMSE<0.11 mm d−1), whose estimations can be slightly improved by assuming a
S-shape crop water stress function.
Key-words: Olive tree, HYDRUS-2D, Soil water content, Actual transpiration fluxes |
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