The Effect of Operating Pressures and Speed Ratios on The Evaluation Criteria of The Center Pivot Irrigation System (Valley) in Al Baghdadi Region

Abstract

A study conducted during the 2021winter season in Al Baghdadi region (150) km west of Ramadi City (Iraq) to show the effect of operating pressure and equipment speed on evaluation criteria of the center Pivot Irrigation Systems. Three operating pressures were used in the experiment, which are 25, 30 and 35 pounds inch−2, with three speeds of 25%, 50% and 75% for each pressure. Study result showed that The pressure 30 pounds inch−2 achieved the highest values for the average of the studied traits, as it was 97.22% while the lowest value was recorded at a pressure 25 pounds inch−2 which amounted to 88.70% with a decrease Ratio 9.6%. The pressure 35 pounds inch−2achieved the lowest average water depth 24.13 mm, while the highest average depth of water was at pressure 30 pounds inch−2 35.89 mm with a height Ratio 32.7%. The lowest average value of the water depth variance (qvar.) was 8.34% at pressure 30 pounds inch−2 while the average of this value increased to 28.63% at pressure 35 pounds inch−2 with increase 70.8%. The ratio of the rotational speed of the arm of the system significantly affected the values of each of the studied traits, the velocity 25% achieved the highest average values 30.93 mm and 93.10%, while the speed 75% achieved the lowest rate 26.58 mm and 89.63% With a decrease 16.4% and 3.8% for each of the applied water depth and Uniformity coefficient, respectively. This speed 25% also achieved the lowest average water depth variance, which amounted to 16.02%, while speed75%achieved the highest value of water depth variance, which amounted to 26.59%, with an increase rate 39.7%.