Monitoramento sazonal do desempenho de um sistema de irrigação por sulcos no perímetro irrigado de São Gonçalo-PB.

Abstract

The purpose of this research was to perform a seasonal monitoring of the furrow irrigation system performance in the São Gonçalo-Pb irrigation district, looking forward to a systematic control of the hydraulic conditions of each irrigation event that would favour a better system performance. To perform this monitoring, it was done: a quantification of the spatial and temporal variations in field parameters; an advance phase monitoring; system performance evaluations; and a monitoring of its operational parameters. The results identified spatial and temporal variations in the furrow cross section. The furrow base was the dimension that showed to be most vulnerable to variations over the season, with a percentage of variation equal to 63%. The advance phases exhibited only temporal variations in the soil infiltration characteristics. In the last four events these variations were insignificant. The advance phase monitoring contributed substantially to balance the deep percolation and runoff water losses. The monitoring of the operational parameters resulted in a significant improvement in the system performance over the season. The application efficiency increased from 41% to 71%, where its seasonal average value was 62%. This application efficiency improvement did not sacrificed the condition of complete irrigation, which was the goal of this research. Without a systematic and adequate management on the operational parameters, the spatial and temporal variations in field parameters might compromise sensitively the furrow irrigation system performance.