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| Titel |
Tracing the allocation of water in rainfed rice ecosystem by partitioning evapotranspiration of rainfed rice (Oryza Sativa L.) |
| VerfasserIn |
Bhone Nay-Htoon, Maren Dubbert, Xue Wei, Matthias Cuntz, Jonghan Ko, John Tenhunen, Christiane Werner |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250112804
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| Publikation (Nr.) |
 EGU/EGU2015-15137.pdf |
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| Zusammenfassung |
| To understand productive and unproductive water use of crop production, partitioning
evapotranspiration (ET ) into evaporation (E) and transpiration (T ) is important. Water
movements within the eco-hydrologic cycle of agroecosystems can be traced by stable
oxygen isotopes of water (δ18O) and plant transpiration and soil evaporation can also be
estimated by tracing the δ18O. We quantified the contribution of transpiration to total
ecosystem evapotranspiration of rainfed rice field by a stable oxygen isotope approach and
FAO 56 dual crop modelling approach. Our study aims to provide quantification of ecosystem
water cycle of rainfed rice by partitioning productive and unproductive water use since
productivity and water use of rice which is a highly water demanding agroecosystem, is under
intense research. Crop season total evapotranspiration fluxes from rainfed rice was mainly
dominated by transpiration (T to ET contribution (T /ET ) = 65%) and domination of
transpiration over evaporation fluxes was noted since early vegetative stage (Leaf
Area Index = 0.8 m2 m-2) until harvesting. T /ET of rainfed rice fluctuated with
changes in soil water content (SWC) and the highest T /ET was found at SWC of
0.34 m3 m-3, during seedling stage. Our results demonstrate that partitioning ET
by FAO 56 dual crop model is in a good agreement with δ18O isotope based ET
partitioning results. Using monthly mean values of leaf resistance and vegetation index
derived crop coefficients instead of original fixed parameters of the FAO 56 dual
crop model resulted better agreement with δ18O isotope based ET partitioning. |
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