Evaluation of some hydraulic characteristics of furrow irrigation system in a Cassava Manihotesculenta crantz field

摘要

Economic design and evaluation of irrigation system takes into consideration the effect of uniformity of water distribution on yields of crops. Yet few research information on scientific methods of determining the required amount of water for irrigation under a predetermined flow rate have been communicated to most agriculturists and peasant farmers in the tropical Africa. This research was therefore aimed at investigating the furrow advance time, recession time, and infiltration rate and water distribution uniformity efficiency in an irrigated cassava field. The experimental design involved furrow irrigation under three different stream flow rates, 0.1,0.39 and 0.57 1/s. The treatments were replicated three times to bring the total number of sampleplots to nine. Furrow intake was highest (0.21 1/s) in the furrow sample 1 where the lowest initial soil moisture content and lowest stream flow rate was introduced. The highest and the lowest water advance time in furrows were 17.4 and 8 minutes, respectively. The highest recession time of water within furrow was 22 min. The highest and the lowest cut-off time were 17.9 and 8.2 minutes, respectively. There was significant difference in water distribution efficiency at the P =0.05 but the lowest streamflow rate produced the highest water distribution efficiency of 82 %. This indicates the possibility of getting the best irrigation even under the smallest stream flow rate, which consequently may result to better water and energy conservation. Result from this research may provide the basis for an in-depth analysis of the control of irrigation for an optimum yield of crop.