Nutrição da erva-mate com sulfato de amônio

Abstract

Mate tea leaves are the product of commercialization of the mate-tea tree (Ilex paraguariensis St. Hil.), which leads to a great export of N, requiring its reposition. In previous nutritional studies of the mate-tea tree, it was observed that its production and metabolism was positively influenced by the ammonium form nitrogen fertilizer. This investigation tested different levels of nitrogen fertilization, in its ammonium form, in a commercial plantation, for verifying its effects on the nutritional status and on the productivity. The experiment was assembled in the region of Ivaí - Paraná, using, as fertilizer, the ammonium sulfate in the dosages of 00, 40, 60, 80 kg N ha-1. The statistical design was randomized blocks, with a split-plot arrangement, consisting of four treatments, two evaluation seasons with five replications and twenty plants per plot, being laid out in a 2,0 m x 3,5 m spacing. The evaluation of the plant’s nutritional status was performed through foliar analysis total N, K, P, Ca, Mg, Fe, Mn, Cu, Zn and Al, in winter and summer, with fertilizations performed for two years. It was concluded that nitrogen supplied in the form of ammonium sulfate has a positive influence on the biomass up to the rate of 52,5 kg N ha-1. The harvesting season influences the plant’s chemical composition. The fertilization significantly influences the foliar contents of N, K and Mg and Zn during winter and Fe, Cu e Al during summer.