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Accueil | Français » Publications » DEA et Masters » Contribution à l’amélioration de la modélisation du bilan hydrique du mil (...)

Contribution à l’amélioration de la modélisation du bilan hydrique du mil (Pennisetum glaucum L.) au Sénégal : mise en relation du niveau d’évapotranspiration avec la surface foliaire

Mémoire présenté et soutenu par Dieudonné Steve MBENDA, le 25 août 2010 à l’UCAD, Département de Biologie végétale pour l’obtention du
Master en Agroforesterie, Ecologie et Adaptation.

Abstract : This study is part of the program of improving agricultural production in West Africa (WAAPP). This program is implemented CERAAS in collaboration with ISRA and CORAF, through the proposed reduction of vulnerability and the intensification of cereal systems in the context of climate variability and change. The main objective of the study is to determine the maximum levels of water consumption of millet, and to relate these levels of water consumption with its leaf area (AIA) and potential evapotranspiration (ETo), to improve the algorithms in the water balance in the model Sarrah. The specific objectives were to monitor, on plots of millet, the water balance to determine water consumption, and parallel developments leaf to determine the ratios ET/ETo cultures, and finally, comparing the ratio ET/ETo with LAI values to establish and/or validate a relationship for determining Kc.
The approach was to implement a trial of millet (Pennisetum glaucum (L.) R. Br.), With different dynamics of growth and development of LAI by the choices of agronomic treatments (variety, density, fertilization). The test was conducted under rainfed and supplemented by irrigation on soil type Dior-Deck "station at NCAR Bambey July 18 to November 15, 2009. The monitoring and measurement of soil moisture, climatic and agronomic parameters related to crop development (phenology, biomass, LAI, ETo, ET, etc.) have been made.
The data obtained were used to verify the different relationships for determining Kc. The maximum values of Kc obtained ranged between 0.94 and 1.79 for Suna, and between 1.10 and 2.02 for Sanio. The observations yielded values of Kc max well above the values recommended by FAO (1.2 to 1.3). These values are between those proposed by Dancette (1.5) and Affholder (1.79 to 1.94). These results seem to confirm results of previous studies conducted in West Africa by Dancette (1978) and Affholder (1995 and 1997), that we can have much higher Kc values recommended by FAO. The results showed that for model parameterization Sarrah, use games max value Kc varies in the range of 1.6 to 2 and 0.5 kdf.

Keywords : millet, Pennisetum glaucum L., water balance, simulation, LAI, AND, Kc, modelling.