Irrigation uniformity with medium size sprinklers part II: Influence of wind and other factors on water distribution

The adequate choice of sprinkler head as well as operating conditions in or der to achieve high irrigation uniformity values is necessary for design pu rpose. Catch-can tests were performed to determine the spatial distribution of water applied with solid set sprinkler systems in open field conditions . Factors affecting water distribution were studied (i.e., direction and sp eed of wind, working pressure, design and number of nozzles, evaporation an d drift losses, height of sprinkler above the ground, etc.). Results show t hat wind speed has a clear negative effect on irrigation uniformity. The la rger the spacing between sprinklers, the lower irrigation uniformity. Unifo rmity increases by using jet-straightening vanes in the main nozzle, double nozzles under low wind speeds and single nozzles under high wind speeds, a nd by locating the sprinkler at 2 m aboveground. In addition, several recom mendations on design and management of sprinkler irrigation systems are inf erred.