| Summary: | 碩士 === 國立屏東科技大學 === 熱帶農業暨國際合作系所 === 95 === Agriculture in Burkina Faso is largely dominated by 75% of rainfed crop production, which is characterized by short and unevenly distribution of annual rainfall. The shortage of water for crop production is not only a consequence of water scarcity, but also mismatches between water supply and demand. Lately, the government launched a small scale irrigation project as a supplementary production strategy, but its succession to rainfed comes too late and does not benefit of the rainy season. A cropping system based on computer simulation model could be helpful for both rainfed and irrigated agriculture to take advantage of favorable climatic condition. But, the low availability of complete weather data limits the estimation of reference evapotranspiration (ETo) with the recommended Penman-Monteith method essential for agriculture water planning. The objectives of this study were therefore to determine a reliable reference model for ETo estimation with limiting data information, examine the crop water balance, establish a cropping calendar and irrigation scheduling. The study was based on crop and meteorological data collected between 1996 and 2005 from two production sites; Banfora and Ouagadougou. Three estimation methods including Penman-Monteith, Blaney-Criddle, and Hargreaves models were applied to calculate ETo for these two sites. In both locations, the trend gives significantly highest estimates values with Blaney-Criddle, while Hargreaves underestimated the ETo. The results showed that the wind affects the ETo, and Penman-Monteith ETo model is ranged between Blaney-Criddle and Hargreaves for most of the time. Consequently, the model by using the equation of (Blaney-Criddle + Hargreaves)/2 might be proposed as it produces the best result when assessed by the root mean square error. The present model is much simple than standard Penman-Monteith method, so it might provide a valuable alternatives for estimating evapotranspiration in the two studied location. The computer CROPWAT simulation model used shows that the crop water requirements (ETm) and its associated irrigation requirements were higher in Ouagadougou than in Banfora regardless of the crop and sowing date. In addition, the rainwater was insufficient for most of the crops in Ouagadougou, but was sufficient in Banfora particularly for maize, dry bean, sorghum, millet and groundnut. In rainfed condition, May was the most favorable planting month for potato, cassava, sorghum, millet, groundnut, rice and onion; and June for maize and dry bean. After the rainy season, if maize and bean are cultivated in September 1st, the rainwater contributed between 39.1 and 42.4% to their water requirements, respectively in Banfora. For Ouagadougou, when cultivated in October 1st, the rainwater contribution is between 6.5 and 7.1%, respectively. It was found that, the irrigation interval and depth were influenced by the climatic conditions. Hence, care must be taken for an eventual extrapolation of these results to other areas different from the study areas. A good cropping calendar as well as improved early maturing varieties could be suggested as recommendation to enhance agricultural water planning efficiency in Burkina Faso.
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