Avaliação do desempenho do microaspersor Rain-Bird QN-14, em condições de campo.

Abstract

This work had the objective of evaluating the performance of the imcrosprinkler RAIN-BIRD QN-14 in the lab and in the field. In lab, the following parameters were deterrmined: coefficient of manufacturing variation, characteristic equation of discharge vs. pressure, profile and precipitation distribution surface. The coefficient of manufacturing variation was 0.007, considered good by ABNT classification. The data of discharge vs. pressure were adjusted through linear regression with a determination coefficient (r2) of 99.98%. The núcrosprinkler showed a precipitation profile in cubic exponential with a determination coefficient (r2) of 99.70%. It showed a precipitation less than 10% of the mean discharge, which is 1.64 mm/h at the surroundings of the emitter, making the effective radius to start at approximately l.OOm from the emitter up to the limit of 3.00m. The Christiansen uniformity coefficient of distribution was 15.43% in the absense of wind. In the field it was evaluated the uniformity coefficient of distribution of water at the surface and in the soil profile at the depths of 0-0.20; 0.20-0.40; and 0.40-0.60m, getting at the respective depths the coefficients of 64.90%, 79.04% and 84.06% and the surface, a mean coefficient of 42.61%. It was noted a pronounced increase between the uniformity from the lab and that from the field. It can be noted that the uniformity in soil profile increase with the depth due to lateral redistribution of the water