Avaliação dos sistemas de irrigação instalados na propriedade Lagoa do Ouro no município de Jequié-Bahia.

Abstract

The objective of this research was to evaluate a center-pivot and a gun sprinkle irrigation systems installed in Lagoa do Ouro farm in the municipality of Jequie, Bahia State, in the period from August to November of 1998. The field evaluations were performed according to the ABNT standards. Different methodologies for determining the parameters of water application evaluation were used (uniformity and efficiency). For the central pivot system, it was verified that the average water depth, measured in each field evaluation, were insufficient when compared to the reference evapotranspiration measured in the tank class A. Analyzing the four radios simultaneously, the Marek et al. statistical uniformity coefficient was equal to 94%. This value indicates that the equipment was well designed and is working appropriately. The distribution uniformity coefficient equal to 63% was considered as unacceptable. Analyzing each radio individually, low values of uniformity coefficients were fund in two of the radios. In these radios, the speed and direction of the wind were the factors of higher influence. The application efficiency for the four radios, analyzed simultaneously, was of 75%, which is considered as acceptable. Analyzing each radio individually, again the two radios presented low values of water application efficiency. For the gun irrigation system, the spacing of 30 x 30m used by the farmer presents a value of the coefficient of uniformity of Christiansen equal to 77%, considered as good. The application efficiency found was of 57%, considered low.