Effect of sewage sludge on the fertility of a Paleudult soil cultivated with sugarcane

Effects of sewage sludge applied to sugarcane, alone (0, 20 and 40 Mg ha(-1)) or combined with mineral fertilizer (NPK), on a Paleudult soil fertility and on the soil heavy metal were evaluated. Soil samples were collected at 146, 272 and 484 days after the sugarcane was planted. Routine analysis for soil fertility evaluation using the resin extraction procedure was performed and S, Cr, Cd, Cu, Fe, Mn, Pb and Zn were also analyzed. Sewage sludge decreased soil acidity and was a source of Ca, P, S and Zn, mainly, but its effects on soil properties lasted only one crop season. Sewage sludge application increased soil heavy metal contents but not to levels considered harmful to the environment.