Fontes e doses de nitrogênio na cultura da banana em região Semiárida

Abstract

The banana (Musa spp. L.) is a fruit widely explored in Brazil and the world and is consumed worldwide due to its nutritional importance. However, the lack of available technologies suitable for crop exploration, such as irrigation, and low soil fertility are some of the reasons for low productivity. Nitrogen is the second most required nutrient by banana being necessary for the proper development and production of the crop. Nitrogen fertilization can be prepared by sources of rapidly available inorganic salts such as ammonium, nitrate and urea, which can increase the electrical conductivity of the soil. The use of urea by the producers is translated by the lower cost of these fertilizers, but the possibility of increasing the soil acidity and the base saturation become unwanted aspects in the application of this fertilizer. Under irrigated conditions, there may be interactions between applied water levels and fertilizer dosages, so that soil pH and soil electrical conductivity levels present different behaviors, which may hinder the absorption of essential nutrients and consequently affect the productivity of the soil. banana. The objective of this study was to verify nitrogen fertilizer responses on yield, soil pH and CE, and nutrient concentrations in soil. The work was carried out on the farm Banesa, which belongs to the company Tropical Nordeste Fruit, located in the municipality of Limoeiro do Norte (CE), in a soil classified as Cambisol Haplic Eutrophic, being cultivated the cultivar of the group Cavendish, in the period from January to December of 2017. The experimental design used was in blocks, in a factorial scheme 3x5 + 1, with three nitrogen doses (Dose 1 = 300 kg N ha-1, Dose 2 = 500 kg N ha-1 and Dose 3 = 700 kg N ha-1), five N sources (urea, blue urea, ammonium sulfate, ammonium nitrate and urea + ammonium nitrate) and an additional treatment (control treatment - Dose 0 of N), with 3 replicates totaling 46 experimental units. At the end of the experiment the following soil variables were measured: pH, EC, and calcium and magnesium contents; in the plant was measured the production and analysis of nitrogen concentration. A higher productivity increase (63.9 t ha-1) was observed when the UAN source (urea + ammonium nitrate) was used. Fertilization with N increased banana productivity, pH, soil CE, and calcium and magnesium concentrations were mainly influenced when ammonium sulfate was used.