Effect of the employment of biosolids as recovery agent for degraded areas

The solid residue generated from the sewage treatment receives the denomination of sewage sludge, being also called biosolid. The present work compared the effect of 3 levels of fertilization (sewer sludge, mineral fertilization and proof) in the recovery of areas with 2 levels of soil degradation simulation (removal of 15 cm and 30 cm of soil), plus a proof. In the parcels destined for the biosolid, 40 dry t./ha of aerobic limy stabilized 30% had been used. The content of Ca+Mg, K, V% and CTC in the parcels that received biosolids had its value increased by 11.7%, 28.0%, 8.3% and 6.0% respectively, when compared with the values of the proof at the end of the maize culture. The contents of phosphorus were statistically higher for the Tukey test at 5% of probability in the treatment with biosolid, verifying also the trend of accumulation of phosphorus in the parcels, with the simulated level of degradation of 30 cm. There was a significant increase in carbon content due to the application of biosolids. The production of dry substance was still evaluated, where the biggest productions had been statistically verified in the treatments, being slightly influenced by the different levels of soil degradation, evidencing the great capacity of silt as recovery agent.