Water Loss from Above-Canopy and In-Canopy Sprinklers

Center pivot systems are currently designed for low operating pressures as a way to reduce pumping costs. Many of the low-pressure sprinkler devices have been designed to operate on drop tubes below the center pivot pipeline. Operating low-pressure sprinkler devices closer to the crop canopy is considered more efficient than high pressure systems. The efficiency improvements are thought to result from reducing the amount of water lost through evaporation and wind drift. Because wind speeds are reduced at locations nearer to the soil surface or crop canopy, placing a sprinkler device just above the canopy reduces the amount of distortion in the sprinkler patter and drift due to wind.