LIXIVIAÇÃO DE POTÁSSIO EM UM CULTIVO DE PIMENTÃO SOB LÂMINAS DE IRRIGAÇÃO E DOSES DE POTÁSSIO

Abstract

With the aim of determining the concentration of potassium (K+) and electrical conductivity (EC) in water drainage in the cultivation of sweet pepper (Maximos F1), and to evaluate the possible risk of contamination of groundwater was conducted a experiment on a battery of 40 drainage lysimeters, whose experimental plot consisted of three plants in each lysimeter, located at campus of the Federal Rural University of Pernambuco (UFRPE), Recife, PE, in a completely randomized factorial scheme 5 x 2, with four replications, being five irrigation depth (80, 90, 100, 110 and 120% of ETc) and two levels of potassium (80 and 120 kg ha-1 of K2O), applied parceled according to phenological phase, through a drip irrigation system, with selfcompensable emitters. Throughout the cycle proceeded to the measurement of volumes generated from natural drainage and the fortnightly water balances in the lysimeters, and collection of samples for tests to determine the K+ and EC. The K+ content and the EC showed significant linear adjustments in all phases of the cycle, whose mean values were 9.79 mg L-1 and 0.35 dS m-1, respectively. The drained volume showed increases in certain events of water balance due to the high rainfall during the period, leaching more potassium ions. It was observed that with the application of higher blade and the higher dose losses were higher K2O, an average 60.10 kg ha-1.