Evaluating the adequacy performances of sprinkler irrigation system at finchaa sugarcane plantation, eastern wollega zone (Ethiopia)

Abstract: The success of sprinkler irrigation system largely depends on its actual performance at field condition. Although the uniformity of water application is the most important aspects in the sprinkler systems performance, adequacy better explains the performance of the system. In this study, the adequacy of irrigation performance was measured actually at field condition considering three operating hydrant pressures (4.0, 4.5 and 5.0 bars) and two sprinkler nozzle sizes (2.4 * 4.4 and 2.4 * 4.8 mm). The main objective of this study was to determine the level of current adequacy of irrigation performance in relation to the predicted performance during the design period. Three different adequacy performances (delivery, infiltration and storage) were determined from the measurements of the two important basic sprinkler performance parameters: discharge and uniformity. The study result indicates excess irrigation water application more than the crop net irrigation requirement and soil moisture deficit, especially for the 2.4 * 4.8 mm nozzles sprinkler at all pressure ranges considered. Inline to this, tremendous losses in terms of deep percolation ( 40%) have been observed, the consequence of which is leaching of soluble nutrients, loss of valuable water resources, reduced crop yield and rise of groundwater table. The later one might lead to drainage problems, which requires construction of expensive drainage system and can also lead to the overall waterlogging, salinization and alkalization of the area