Solubilization of phosphorus, soil correction and corn yield after addition of phosphates and natural and composted tannery sludge

Solubilization of phosphorus, soil correction and corn yield after addition of phosphates and natural and composted tannery sludge. The objective of this study was to evaluate the effect of tannery sludge associated with fosforita (rock phosphate) on the availability of phosphorus and correction of soil, leaf levels and maize yield. The experiment was conducted on the field during twelve months (October 2005 to October 2006) with the incorporation of 2.5 and 5.0 Mg ha(-1) of tannery sludge (natural and composted) and 100 kg of P2O5 ha(-1) in the form of soluble and natural phosphate (fosforita). During the months of November 2005 to April 2006, maize was grown in the experimental area. Treatment with tannery sludge naturally, at a dose of 5.0 Mg ha(-1) associated with fosforita, incremented the levels of phosphorus, calcium and base saturation in the soil for 360 days after implementation. This treatment provided increases in levels of phosphorus in the leaves of maize. The composted tannery sludge treatment, compared to natural tannery sludge, was deficient in the absorption of phosphorus by maize and soil correction. Increased yield of maize was verified by the incorporation of fosforita associated with the natural and composted tannery sludge at a dose of 5.0 Mg ha(-1).