Effect of potassium on the leaching of chemical species in a soil treated with sewage sludge

Abstract

The objective of this research was to evaluate the potassium interference, used as supplementary fertilization, in the ions leaching, in a soil that was treated with alkalinized sewage sludge and cultivated, with maize. The experimental set with sewage sludge results showed an increase of the potassium concentration and chloride concentration in the leached solution, as well as the reduction of the Al3+ concentration, as the doses of potassium fertilizer applied to the soil were increased, for the four teachings. The presence of sewage sludge treated with lime increased the concentration of NO3-, Cl-, Ca2+, Mg2+ and Al 3+ in the solutions in the majority of leachings. Values of Al 3+ were higher than 0.1 mg L-1, than in all leachings when sewage sludge was added to the soil. For nitrate, all the solutions presented values higher than the maximum value allowed by the current law (10 mg L -1).