Distribuição de água do microaspersor ED2, em solo com barreira impermeável no perfil.

Abstract

This study was carried out with the ~, main objective of determining some pa r ame te rs of a fixed micro-sprinkler wit'h sectorial distribution, named £$2> under field con d 1tions,such as surfa ce wetted a re a , wet bulb pattern wi thi n the soi 1 prof i le , infiltrated volume, and application efficiency. The fleid work was conducted in an Eutrophic Regosol with Fragipan soil, at "Sitio Prensa", in Souza city, Paraíba, Brazil. Tests were made, consisting in applying theree precalculated volumes of water to raise soil moisture to field capacity level down to the depths of 25,50,-and 75cm (treatments A, B and C). . The surface area wetted by the micros p:r i & k 1 e r were 1 1 . 8 9 , 12.79 and 13-^3 rn2 in the respectives treatments A, B , C. The analysis of water con tents in the soil, after Írrigation , showed that the effective wet buib reached an average depth of 8 , 12 and 19cm, and the wetting front reached 31,^0 and 48cm , for treatments A , B and C, respectively. Application efficiency had an average of 80.27 percent whereas storage efficiency was 6 5 . 7 1 , 50.51,and h).\S percent for treatments A, B and C. Treatment A presented the best efficiency of application, and treatment© B the best 'distribution of applied water depth. The presence of a layer with ..low; permeabi 1 tty at approximately 22cm in the soil profile made it difficult for the wet bulb to drop fus the r. And the micro--sprinkler was found very sensitive to the effect of winds, even light ones (1,13* to 2,87 m / s ).