Performance Evaluation of Infield Sprinkler Irrigation System under Existing Condition in Beles Sugar Development Project, Ethiopia

Fikadu Kinfe Abshiro1 and P

Abstract

In Beles Sugar Development Project sugar cane fields was faced poor irrigation water management that under watering in most fields, dry spot and over watering in rare fields were observed. Therefore, the main objective of this study was evaluating the performance of infield sprinkler irrigation system under existing condition. The actual water application uniformity was measured for single and four overlapping sprinklers by installing catch can at a grid spacing of 3 × 3 m with two replications at hydrant pressure of 2.5 and 3.0 bars. The performance parameters analyzed were, uniformity coefficient (CU), distribution uniformity (DU), and system uniformity, pressure and discharge variation along laterals also analyzed. The average actual DU and CU obtained at 3 and 2.5 bars at existing sprinkler spacing of 18 m ×18 m was 53% and 63% respectively. The value of CU was lower than the recommended value of 75%. In order to determine alternate sprinkler spacing’s under existing working condition, the catch can data for single sprinkler were overlapped for different spacing’s whereas respective DU and CU were estimated. For both 2.5 and 3 bar operating pressure; 12 × 18 m, 12 × 12 m, 18 × 12 and 9 × 12 m sprinkler spacing’s were in between good and excellent acceptable range. Keeping in view economy, wider spacing, 12 × 12 m is recommended to have excellent water distribution with CU equal to 85% and 87% at operating pressure of 2.5 bar and 3.0 bar respectively. The actual average sprinkler discharge variation along laterals was above and out of the range accepted value up to 10%, whereas the actual average pressure variation along laterals is within the accepted range value of 20% but in some field laterals other than the test area, the variation was above the accepted range value of up to 20%