Proceedings of the 29th Annual Central Plains Irrigation Conference, Burlington, Colorado, Feb. 21-22, 2017 Available from CPIA, 760 N. Thompson, Colby, Kansas 19 CENTER PIVOT IRRIGATION SYSTEM LOSSES AND EFFICIENCY Danny H. Rogers Jonathan Aguilar Extension Agricultural Engineer Extension Irrigation Specialist Biological and Agricultural Engineering Southwest Research-Extension Center Manhattan, Kansas Garden City, Kansas Voice: 785-532-2933 Voice: 620-275-9164 Email: drogers@ksu.edu Email: jaguilar@ksu.edu Isaya Kisekka Freddie R. Lamm Research Agricultural Engineer Research Agricultural Engineer Southwest Research-Extension Center Northwest Research-Extension Center Garden City, Kansas State University Colby, Kansas Voice: 620-275-9164 Voice: 785-462-6181 Email: ikisekka@ksu.edu Email: flamm@ksu.edu Kansas State Research and Extension INTRODUCTION Nearly 85 percent of the irrigated area in the three states of Colorado, Kansas and Nebraska are watered using center pivot sprinkler irrigation systems (NASS, 2013). Center pivot irrigation systems have been adopted because of their ruggedness and versatility. Center pivot systems reduced the amount of labor associated with irrigation as compared to surface irrigation systems and usually apply water to a crop more efficiently and uniformly. Declining well capacities in many irrigation areas and producer desire to reduce pressure requirements to minimize irrigation pumping costs have prompted development of different water delivery package options for center pivot systems while maintaining the ability to efficiently and to uniformly distribute a limited water supply over a large area. It is important, when designing a water delivery package for a new system or replacing a water delivery package on an older system, to keep in mind the general performance requirements of the various devices used to distribute water throughout the irrigated field. If these general requirements are not followed closely, a reduction in the system efficiency could occur which could be due to increased runoff and reduced yields from under-watering due to poor uniformity. The following will discuss the various options available for use with center pivot irrigation systems and their general performance requirements. To provide a better understanding of conditions which reduce efficiency, the discussion will cover water losses associated with the various attachment options and configurations. APPLICATION DEVICES: CHARACTERISTICS AND DESIGN CRITERA The water emitting devices that allow the distribution of water to a field from the center pivot system are often called the sprinkler package, even though the water distribution devices may not resemble a traditional sprinkler device. Sprinkler or water delivery packages can be composed of a range of devices including impact sprinklers, fixed plate spray nozzles and moving plate spray nozzles or other water emission devices such as drag hose and/or drip tube. The latter application