Impact of operating pressure and weather elements upon distribution uniformity and conveyance efficiency of mini-sprinkled irrigation water

Abstract EN

This research aimed to examine operation of mini-sprinkler irrigation system and determine the best operational conditions.

Such conditions attain best water distribution uniformity and higher conveyance efficiency.

Hence, best production per utilized irrigation water unit would be attained.

Also water would be saved for wider land reclamation projects.

Related to the precipitation rate value, the area irrigated through a single mini-sprinkler (Mikroregner) of about 1.75 mm nozzle diameter could be distinguished into four zones surrounding the mini-sprinkler.

It was noticed through the irrigated plants had different growth in each zone.

Such zones are, 1 (0 - 120 - ), 2(120-230-), 3 (230-300-), and 4 [ 3oo - 350 ( 400 ) cm ] from the mini-sprinkler.

The precipitation rate decreases as the distance from the mini-sprinkler increases.

For an experiment was conducted with a 0 .83 bar (12 psi) nozzle operating pressure under 0.2 m/s wind velocity, 14.4-ai- and 35.0 ˚C water temperature, 69.3 % relative humidity and 3.8 m bar vapor pressure deficit, on the average, the wetting depths amounted to and 0.32and 0.32 mm / h, on the average at zones 1, 2, 3 and 4 respectively.

Other distribution uniformity standards including the favorable irrigated area portion, uniformity coefficient Cu statistical uniformity coefficient SCu and uniformity coefficient UCH were 48.2-, 50.4 -, 33.6-and 47.0%, respectively, and the conveyance efficiency amounted to 93.6%.

The favorable irrigated area portion, Cu and UCH were similar at nozzle operating pressures higher than 0.76 bar (11 psi).

On the other hand, amounted the average wetting depth at zone 1 (0-120 cm) to times that at the other zones, the favorable irrigated area portion was less than 15.5 %, Cu, SCu and UCH had negative values at nozzle operating pressure lower than 0.76 bar (11 psi).

The pattern efficiency PE according to National Resource Conservation Service is not suitable distribution uniformity standard under such conditions .

Air (14.0-23.0˚C) and the about 1.75 mm nozzle diameter cause more spray losses than recorded in the diagram illustrated in p.386 in Achtnich (1980).