Abstract:
The main objective of this study was evaluating the technical performance of center pivot sprinkler irrigation during the growing season and when operating with different working speed. The evaluations entailed system and individual nozzle flow rates, travel speed, and depth and uniformity of applied water. Transects of catch cans extending radically from the pivot points are used to provide data on depth and uniformity. Both standard statistical methods (mean, standard deviation, and Christiansen coefficient of uniformity) and time-pace series statistics are employed to analyze the can data.
The evaluation activities were made at early, mid, and late in the crop growing season and with 50, 75, and 100 % speeds. From data of system performance it is found that: Cu varies from 86, 88, and 89 % for early, mid and late season respectively. Du values were 78. 81 and 83% for early, mid and late parts of the season respectively. Performance due to Ea is fair to good with values of 88, 84, and 85% for early, mid and late season respectively. Dependability of the system with reference to Ea, Cu, and Du is a round 93% irrespective of the stage of the season and can be rated as good for the system in use is new and free from breakdown. Impact of changing operating speeds on system performance reveals that the obtained Cu values are higher than those reported for Sudan They reach values of 87.6, 85.5 and 88.8 % for 50, 75, and 100% speed respectively. For Du the results obtained indicate poor levels for low (50%) and medium (75%)speeds, while a higher value of 83% is obtained with the maximum operating speed(100%). Results of evaluation due to Ea with respect of speed indicate low level of performance in general and the performance increases with increase of speed. This is due to the fact that with low speed evaporation losses increases
Key words: Technical performance, center pivot sprinkler, dependability. System efficiencies
