Cost defines the type of nitrogen fertilization for coffee trees initial development

Abstract

Several fertilizer-associated technologies are available on the market capable of promoting greater effectiveness in nutrients use and availability to crops. In coffee growing, the classes of nitrogen fertilizers with enhanced efficiency stand out. Hence, this study evaluated the efficiency of different types of nitrogen fertilizers in coffee trees development compared by use cost. We conducted two experiments: one in the field, in Campos Gerais municipality, Minas Gerais, and another in a greenhouse. Aside a control treatment (without nitrogen application), the following nitrogen fertilizer technologies were tested: conventional fertilization, slow-release fertilizer and controlled-release fertilizer, according to manufacturer’s recommendations. In the pots, we adjusted the fertilizer dose according to the volume of soil available to the root system. Height, stem diameter, number of primary branches, crown diameter, soil plant analysis development (SPAD) index, leaf nitrogen (N) content, number of plants regrowing after frost, root and shoot dry mass and use costs were assessed. Results showed a difference for crown diameter and SPAD index in the field experiment. Regarding crown diameter, the controlled-release treatment was superior only to control. As for the SPAD index, control was inferior to all other treatments. In the pots, all the analyzed variables were superior to the control, excepting root dry mass, which showed no difference. In terms of cost, conventional fertilization was the least costly.