Design and Maintenance Factors Affecting Application Uniformity of Low Pressure Center-Pivot Irrigation Systems

Uniformity tests were conducted on 30 center-pivot sprinkler systems installed with one of six different low pressure nozzle types or high pressure impact sprinklers. Well designed and maintained nozzles will produce uniform application. However, several design and maintenance factors were identified which can reduce application uniformity to an unacceptable level. Coefficient of uniformity data will be presented comparing pumping plant maintenance and design, nozzle spacing, use of drop-tubes, use of an end-gun and poorly maintained nozzles.