Résumé : |
In order to evaluate if the tannery residue derived from an industry of rio grande do sul state could be used as fertilizer and amendment, laboratory assays and experiments were conducted with two red-yellow podzolic soils. The residue presented important elements to the plants' nutrition such as nitrogen (N), phosphorus (P), potassium (K), sulfur (S), calcium (Ca) and magnesium (Mg). In the residue, the heavy metals nickel (Ni), chromium (Cr), lead (Pb) and cadmium (Cd) were predominantly in nonavailable forms to the plants. It increased the pH and the cation exchange capacity of the soils and may be used to correct the pH of the acidic soils. In free drainage condition, the residue application, in rates varying from 0 to 11.1 g residue kg-1, did not show salinity problems to the soils and in spite of its high pH and high chromium content, in rates of 0, 4.4 and 8.3 g residue kg-1, it was not harmful to the rye growth. |