Fertirrigação nitrogenada com gotejamento na cultura da berinjela

Abstract

The aim of this study was to evaluate the effect of nitrogen levels applied by fertigation with drip irrigation system in the culture of eggplant “Ciça” (Solanum melongena L.) in a Oxisol in the municipality of Dourados-MS, Brazil. The experiment was conducted from August 2012 to February 2013, in the area of Irrigation and Drainage, the Faculty of Agrarian Sciences (FCA) of the Federal University of Grande Dourados (UFGD) in Dourados-MS. The experimental design was a randomized block in a split plot scheme consists of four blocks. In plots treatments were five doses of nitrogen (zero, 50, 100, 150 and 200 kg ha-1). In the subplot treatments were three positions of drip hose deep into the soil (surface, buried 0.1 m and buried 0.2 m). In all treatments was used as a source urea installments in six applications cover using fertilizer injector with pressure differential. The irrigation system is the type located and drip irrigation management was performed using an estimated reference evapotranspiration by Penman-Monteith method. The eggplant culture was transplanted on 19 August 2012 and harvest began 89 DAT and extended until extending for about four months, up to 171 DAT. The characteristics evaluated were: average weight of fruit; number of fruit, fruit length, upper and lower diameter, overall productivity, business productivity, efficiency in water use and maximum economic efficiency. All variables were subjected to analysis of variance by F test, when they were at least significant at the 5% level of probability was applied the Tukey test to compare the means for the source of drip variation, and applied to the nitrogen source variation compared using regression model. It can be concluded that eggplants significantly responds to levels of nitrogen by fertigation. With use of subsurface drip 10 and 20 cm, there are savings in the total applied blade. The average mass and the eggplant fruit number are influenced by surface drip and buried. The nitrogen dose of 100 kg ha-1 compared with the zero rates, enables increase in total eggplant yield in the order 110%, 92% and 119% when irrigated by surface drip, buried 10 and 20 cm respectively. As for business productivity gains are 115%, 97% with the fertilization of 100 kg N ha-1 and 127% at the dose of 150 kg ha-1 of nitrogen. With use of drip buried 20 cm and association fertilization of 150 kg ha-1 of nitrogen efficiency in water use gets gains of 120%. In the eggplant culture, there is no difference between Maximum Economic Efficiency and Maximum Efficiency Technique depending on nitrogen costs regardless if the drip is superficial or buried. The Maximum economic efficiency is found using the dose of 100 kg N ha-1 with surface drip fertigation.