Diagnóstico e avaliação de desempenho de drenagem subterrânea no perímetro irrigado de Bebedouro-PE.

Abstract

The research was conducted in field of smail producers (average of 2.2 ha), composed of three trials (01, 02,03), which had the same soil type and the grapevine crop, at the same age, but the impermeable layer deepness and the underground drain spacing were changed. A drainage system performance evoluation was dane by making hydroiogic parmeter field measurements and by using the DIELEMAN & TRAFFORD (1984) methodology. The trials were done in a podzolic red yellow eutrophic soils spacing, installed at an impermeable layer deeper than 3.0 m; the trial 02 had three drain spacings (35.0 m, 40.0 m and 58.0 m) and Impermeable layer depth volrylng from 1.4 m to 2.20 m; and the trial 03 had drains spaced 19.6 m, 23.3 m and 35.0 m, and impermeable layer depth changing from 1.6 m to 1.8 m. The results showed that for the conditions of trial 01 there is no need for underground drainage; the 35.0 m drain spacing, in the trial 02, presented a good performance for the situations where the impermeable layer deepness was from 1.4 m to 1.8 m, while the 58.0 m drain spacing had a good performance for an impermeable layer at depths varying from 1.8 m to 2.2 m. In these conditions, the Hooghoudt ande tehe Glover-Dumm models gave drain spacing estimations close to the one that resulted in a good performance. In the trial 03, the 35.0 m drain spacing was the one that presented the best performance for the impermeable layer deepness varying from 1.6 to 1.8 m with a gravel interface at 1.2 m deep, and the Hooghoudt, Ernst e Glover-Dumm models gave the best drain spacing estimations.