Design and evaluation of bubbler irrigation systems

Abstract

Low-head bubbler irrigation systems are particularly well-suited for the irrigation of orchard crops, and these systems differ from other micorirrigation systems because they are based on gravity-flow, can operate at pressures as low as 1 meter (3.3 ft), and do not require elaborate filtration systems. A design procedure for low-head bubbler systems is described in detail, and example designs for bubbler systems located on level ground and gradual slopes are also presented. The design procedure utilizes head loss gradient charts based on the Darcy-Weisbach equation to size the pipe diameters, and the delivery hose elevations are calculated by using a personal computer with spreadsheet software. The causes of air locks in the laterals and delivery hoses are also investigated, and minimum design flow rates for various pipe diameters are recommended to ensure flow velocities are high enough to prevent air locks from occurring within the delivery hoses.