Desempenho da rega por sulcos na estação agrária do Umbeluzi – distrito de Boane

Abstract

The present work is a study on the performance of furrow irrigation at the Umbeluzi Agrarian Station conducted by assumptions that raise problems such as inadequate furrow irrigation practices that lead to poor performance. For this purpose, the general objective was to assess the performance of the furrow irrigation method in order to determine and discuss the results of application, storage, uniformity, deep percolation and surface runoff efficiencies. In this context, the work was based on two study models in which a theorist who portrays on the analysis of historical data such as rainfall data in the Umbeluzi Basin, soil data and irrigation practices, and the other aspect was based on the practical model related to field measurements where determinations were made, such as topographic survey, water infiltration test in soils; measuring the flow of water in the grooves; the advance and recession of water in the furrows; the cross section of the grooves and the analysis of the soil at the station. From the result of these measurements, it was found that the field has conditions that are suitable for furrow irrigation. In relation to the soil infiltration tests analyzed based on the magnitude of the allocation for the 1st and 2nd furrows (96 and 95 mm) and the time to infiltrate these appropriations (28 and 27 minutes) it was found that these belong to the infiltration class high, although the result of the soils proved to be “Franco-sandy” this infiltration can vary (decrease) depending on the watering interval. Regarding the flow measurements for the two furrows measured with lengths of 120 meters each, for the 1st and 2nd furrows (6.33 and 5.23 l / s / furrow), these values ​​are high for the slopes that the field presents and they are like this influenced by UAE irrigation practices. Based on the data obtained in the field measurements, irrigation efficiencies were determined based on the modeling and the two (2) software used presented values ​​such as (54 and 59%) for the application efficiencies (and a) for the 1st and 2nd furrow in the first software, and (62 and 67%) for the 1st and 2nd groove in the second software. For uniformity efficiencies (e u) in the first software for the 1st and 2nd grooves the values ​​are (94 and 92%) and (69 and 74%) for the 1st and 2nd grooves in the second software. The evaluation was made based on application efficiency and uniformity of distribution. Thus, the performance of the system was shown to be low, which led to the optimization of efficiencies and the results improved based on the reduction of parameters such as the length of the groove, the application time and the respective flow rate applied (TRADUÇÃO NOSSA)