Avaliação de sistemas de irrigação localizada de baixo custo recomendado a pequenos agricultores da região semiárida

Abstract

With the growth of irrigation, the need arises for more efficient systems for the use of water. Low cost irrigation systems enable greater efficiency providing productions at relatively lower prices. With that thought, the aim with this work was to evaluate low cost localized irrigation systems that meet theoretical specifications and, above all, to be accessible to farmers. This work was accomplished in two moments, the first being in the Hydraulics Laboratory of the Department of Environmental Sciences and Technological and the second in the Experimental Farm Rafael Fernandes, both of the Federal Rural University of the Semiarid (UFERSA), in Mossoró, RN, Brazil, generating usage information of irrigation systems submitted to pressures of 10, 20 and 30 kPa. Initially we evaluated the emitters on a test bench, where it was determined the coefficient of manufacturing variation (CVf), the distribution uniformity coefficient (CUD) and the average flow (qmed) of the same, in certain pressure conditions. With the information generated were determined maximum allowable lengths of the lateral line, in function on the pressure variation (Δq). The results was provided to formulate an alternative kit (six lateral lines of 16 mm diameter, spaced 1 m between themselves, with 15 m length, perforated manually, where was inserted at every 0.3 m, a dripper type GA-4). Along with a commercial kit of the John Deere Water (formerly Plastro), both were submitted and evaluated under field conditions through the distribution uniformity coefficient (CUD), of soil characteristics and the materials used. The kits demonstrated the viability of usage adequate when in low pressure (10, 20 and 30 kPa)