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| Titel |
Where do roots take up water? A method to quantify local root water uptake |
| VerfasserIn |
M. Zarebanadkouki, Y. Kim, A. Carminati |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250060658
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| Zusammenfassung |
| During the past decades, considerable advances have been made in the conceptual
understanding and mathematical description of root water uptake process. A large number of
models of root water uptake with different degrees of complexity are now available. However,
effective application of these models to practical situations for mechanistic description of root
water uptake requires proper experimental data. The aim of this study is to introduce
and test a non-destructive method for quantifying local water flow from soil to
roots.
We grew lupin in 30Ã25Ã1 cm containers. Each container was filled with a sandy soil which
was partitioned into different compartments using 1cm-thick layers of coarse sand.
Deuterium (D2O) was locally injected in soil near the root surface of 18-day old plans. The
flow of D2O into transpiring plants (day) and non-transpiring plants (night) was traced using
time-series neutron radiography.
The results showed that: 1) D2O entered the roots faster during the day than night; 2) D2O
quickly transported inside the roots towards the shoots during the day, while at night this flow
was negligible. Differences between day and night were explained by convective flow of
water into the root due to transpiration. To quantify the transport of D2O into roots, we
developed a simple convection-diffusion model. The root water uptake predicted by the
model was compared with the direct measurements of axial water flow in the roots. This
new method allows for quantifying local water uptake in different parts of the root
system. |
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