Desempenho de um sistema de irrigação por aspersão com canhão hidráulico em função da velocidade do vento e do espaçamento entre aspersores

Abstract

The work was conducted in a field belonging to Companhia Agroindustrial Vale do Curu (AGROVALE), in the county of Paracuru-CE/Brazil. The main objective was to identify the performance of a solid set hidraulic gun sprinkler system submited to variable wind velocities, directions and sprinkler spacings. The secondary objective was a general evaluation of the system performance. For this the MERRIAM & KELLER (1978) procedure was applied and Christiansen's Uniformity Coefficient (UC), Uniformity of Distribution Coefficient (UD), Irrigation Efficiency (IE), Applied Water Loss (AWL), Potential Application Efficiency (PAE), Evaporation Water Loss (EWL) and Water Drip by Wind (WDW), were determined. The irrigation quality parameters were determined to seven (7) sprinkler spacings (36 m x 36 m, 36 m x 45 m, 45 m x 45 m, 45 m x 54 m, 54 m x 54 m, 54 m x 63 m and 63 m x 63 m) and to wind velocities ranging 0 - 1, 1 - 2, 2 - 3, 3 - 4, 4 - 5, 5 - 6 and 6 - 7 m/s. The values of UC, UD, IE and PAE, showing the best irrigation performance, were obtained within the lowest wind velocities intervals, and spacings of 36 m x 36 m (90%, 85%,71% and 84%) and 36 m x 45 m (88%, 82%, 70% and 82%). Values of UC, UD, IE and PAE lower than the values above mentioned indicate the influence of wheather factors (wind velocity and direction, temperature, air relativy humidity) and non-weather factors (operation pressure, sprinkler spacings), producing loss higher than 30% and performance lower than the one recommended by the literature.