灌漑・排水システム工学

Evaluation of Sprinkler Heads at Beles Sugar Development Project

Abstract

Fikadu Kinfe Abshiro*, Kidane Tesfa Michael Gadisa and Mayet Feleke Adugna

Beles sugar development project has faced the problems of inadequate and poor uniformity of irrigation water. Thus, the system has failed to meet the crop water demand. Having this, the plantation section irrigators were made the two combined sprinkler heads in one HDPE pipe which is fitted with the main riser like the single sprinkler head. By applying the modified combine sprinkler heads, the cane under water stress has recovered soon relative to the existing sprinkler head. The correlated challenge was the irrigation set hour of the modified combine sprinkler heads was not known and its technical comparative discharge advantage was not determined. Thus, this research work was undertaken to compare the modified two combined sprinkler heads with the normal single sprinkler head and to develop sprinkler set hour under the current operational situation. The parameters evaluated were sprinkler discharge, net depth of water application, gross depth of water application and sprinkler set time. The modified combined sprinkler heads had 43% more discharge than the normal single sprinkler head at the same hydrant pressure of 2.5 bar. The sprinkler set time of the modified combine sprinklers heads at the growth stage of 0-3, 3-6, 6-15 and above 15 months was reduced by 43.5%, 41.2%, 43.5 % and 42.6% respectively compared to the normal single sprinkler head.

within the same design irrigation interval of 15 days and 18 × 18 m sprinkler spacing, the modified combine sprinkler heads at 0-3, 3-6, 6-15 and above 15 growth stage has the sprinkler positions and area coverage of 28, 18, 14 and 9 and 0.907, 0.583, 0.454 and 0.292 ha respectively. The modified combine sprinkler heads is better to cover the area with short time and better amount with relative to the normal single sprinkler head.