Quantitative and Qualitative Analysis of Sewage Sludge Application to Soil Degraded by Livestock

Sludge presents a high organic matter content (OM) and, therefore, can play an essential role in soil conditioning. Thus, the present study's objective was to analyze, quantitatively, and qualitatively, the physical and chemical changes caused by the application of sewage sludge to soil degraded by livestock. The experimental area is located in the city of Paragominas, PA, and it is 36 m2. Regarding the sludge applied, it was generated at the Wastewater Treatment Plant (WWTP) of the condominium Morada do Sol, within the city's urban area. We applied the deductive method, with a quantitative and qualitative approach, associated with research in a time frame between 2011 and 2020 to collect documentary data. The data analysis allowed to infer that: 1) the sludge presented high nutritional content, which can be indicated by the level of OM ( = 86.5%); 2) in control (untreated) soil, we verified critical data on soil density ( = 1.2 g/cm?) and nutritional deficiency of both P, with a shallow content ( ? 2.6 mg/kg), and K, with ?low? content ( ? 38.7 mg/kg); 3) in the soil, 60 days after the application of 3.0 kg/m2 of sludge, occurred a decrease of 8.3% in soil density and increases in the concentrations of P (392.3%) and K (70.5%), which now are in ?good? and ?average? levels, respectively, and 4) the data variation was considered not significant for physical attributes and significant for the chemical ones. Therefore, the sewage sludge proved to be viable for the recovery of degraded pastures.