DESIGN OF BUBBLE IRRIGATION SYSTEM WITH EMITTERS AT GROUND LEVEL

In the Brazilian semi-arid, sustainable growth rates and higher standards of living in society may be attained by the use of irrigation aiming at obtaining the best economical function without disregarding several factors, such as labor, soil, and water supply. The objective of this work is presenting an alternative design procedure for low-head bubble irrigation systems so as to make the technology more accessible to users. An electronic spreadsheet was developed and made available for sizing laterals and delivery hoses at ground level based on the principles of mass conservation, energy conservation and friction head loss. 9 combinations of spacings between plants and between rows were used with different lateral lengths, resulting in 22 designs operating at 9.8 kPa (1 m.w.c). Designs were subjected to hydraulic and efficiency tests. Uniformities of water application were computed using Christiansen’s uniformity coefficient and distribution uniformity coefficients. Designs were ranked according to the proposed classification of Mantovani. Irrigation uniformities, above the recommended limits and with low variability across designs, allow us to conclude that the design procedure for the proposed irrigation system is feasible.