Influence of the fertilization with organic dejections and mineral fertilizer on the tenor of heavy metals in soil and sugarcane

The fertilizing inadequate by means of organic residues can add heavy metals to soils and plants. Thus, this study evaluated the movement of heavy metals in the soil and in sugarcane in the region of Uberlândia- MG, after fertilization with chemical fertilizer and organic waste, at different depths and cane growth periods. The study area was the farm of Cia Mineira de Açúcar e Álcool do Triângulo Mineiro Ltda, located in the municipality of Uberlândia, State of Minas Gerais. The experimental design was randomized blocks, in a 5x2x4 factorial, with split plots in time, corresponding to five fertilizer types: chicken bedding (CF), turkey bedding (CP), composted manure (AC), cattle manure (EB) and the control, all combined with the presence or lack of agricultural gypsum; analyzed at four depths and at two times. The heavy metals was evaluated in the soil, sugarcane stalk and leaves. The results obtained were submitted to analysis of variance and the averages of the factors compared by the Tukey test at 0.05 significance. The heavy metals contents in the stalks were smaller in time 2. In contrast, heavy metals stalk contents did not exceed the critical limit. No Cd and Cr were detected in the soil, while Ni and Pb were below the critical contamination limit. Agricultural gypsum did not affect the levels of micronutrients or heavy metals in the soil or in the sugarcane.