Sprinkler packages and their configurations for center pivot irrigation

The last decade has seen development of some new and innovative sprinkler/spray head designs for use with center pivots and traveling laterals. The impetus behind these devices has been the need to maintain uniformity of water application equivalent to the high pressure overhead sprinklers, while reducing energy requirements, spray drift losses, and controlling potential runoff. Ease of installation, maintenance and long life were also important considerations. Spray head designs have evolved from the simple smooth or grooved fixed-deflector plates to rotating or oscillating plates designed to produce larger patterns or control droplet sizes. Pattern diameters produced with various types of spray plates operating at various nozzle pressures, and nozzle elevations, are given and uniformity attainable on moving laterals is discussed. Peak application rates and droplet size issues are also discussed. Various mounting methods such as adjustable drops or offset booms are available to vary the spray elevation, allow in-canopy spray or to increase the pattern width and reduce application rates.