Sewage Sludge Application Treated by N-Viro Process in No-Till Soils. Agronomic and Environment Effects.
Jetro Turan Salvador1, Luiz Antonio Corrêa Lucchesi1, Tereza Cristina de Carvalho1, Uéliton Trindade de Oliveira1, and Antonio Carlos Lacerda2. (1) Univ Federal do Paraná, Rua dos Funcionários, 1540, Curitiba Paraná, 80035-050, Brazil, (2) Alto Iguaçu Engenharia, Agronomia e Ambiente Ltda, São Jose dos Pinhais, São José dos Pinhais, Brazil
Sewage sludge use in agricultural systems improves soil chemical attributes that can increase agronomic productivity. This procedure, well-known as agricultural recycling, is a sustainable alternative to avoid eventual negative impacts of sewage sludges in the environment. However, for the recycling to occur safely, sewage sludge treatment is necessary. A methodology of easy execution, with economic viability and great credibility is the “Advanced Alkaline Stabilization with Subsequent Accelerated Drying” or N-Viro Process. The sewage sludges treated by this process, are stabilized, and have acceptable environmental quality standards (Class A sludge). They present high pH as well high calcium content. After surface application of sewage sludge in No-till systems, the calcium linked to the organic matter could leach in soil, and reach the sub-surface allowing better root development, providing a better condition to increase agricultural productivity. Brazilian farmers, as well the academic community, requests more information about the agronomic and environmental effects of such applications. The objective of this study was to evaluate calcium leaching from surface application of treated sewage sludge (by Process N-Viro), environmental parameters, and effect on crops in comparison to limestone and gypsum under greenhouse and field conditions. The preliminary results indicate that sewage sludges treated by N-Viro Process are capable of supplying calcium to soil and plants, neutralizing soil acidity, increasing Ca leaching along the soil profile, and improving crop productivity.