Especiação do cádmio em Brachiaria brizantha e biodisponibilidade dos macro e micronutrientes

Abstract

In order to assess the influence of Cd on the content, translocation of nutrients and growth of Brachiaria brizantha, an experiment was set up in nutrient solution in a greenhouse in the Department of Soil Science, at Universidade Federal de Lavras. Cadmium was applied at 0, 0.025, 0.50 and 1.00 mg/L. The experiment was set up as a completely randomized design (CRD) with four replications. Data were submitted to principal component analysis (PCA). The results showed roots with high amounts of nutrients and Cd, and aboveground parts with high levels of Mg. Ca levels were higher in the control treatment. Smaller doses of Cd induced an increase in the levels of Cu, Mn, Zn, Fe, N, P, K and S. The levels of K and Cd increased with the application of Cd. The translocation rate decreased for Cu, Mn, Zn, Fe and N, and increased for Ca, Mg and Cd. Sulfur showed irregular variations in translocation rates. Despite variations in the levels and translocation of nutrients, the doses of Cd used do not cause changes in the growth of Brachiaria brizantha, a fact attributed to the plant tolerance to this heavy metal.