Utilization of sewage sludge in the seedling growth of aroeira (Schinus terebynthifolius Raddi) seedlings

This work aimed to evaluate sewage sludge as substrate component for aroeira seedling growth. Substrates were composed of soil samples collected at 0.2-0.5 m depth from a Quartzarenic Neosol or from a Red-Yellow Latosol, with sewage sludge produced by the Sewage Treatment Station (Estação de Tratamento de Esgoto - ETE) located in Serrania, Minas Gerais, in five proportions: 100:0; 80:20; 60:40; 40:60 and 20:80, being all without mineral fertilizers. Thirty days after sowing, thinning was carried out to one plant per pot. Aroeira growth after 60 days was evaluated by shoot and root dry weight, total dry matter, stem diameter, plant height, leaf area, shoot height/stem and diameter shoot/root ratio. Amendments with sewage sludge increased substrate fertility as indicated by P, K, Ca, Mg concentrations, CEC and SB values, organic matter and micronutrient contents, which promoted growth of stem diameter, plant height, shoot and root dry weight, total dry matter, leaf area, and shoot/root ratio in aroeira seedlings . The effect of sewage sludge on aroeira seedlings growth varied according to the different proportions of sewage sludge. Maximum growth was obtained with the proportion 37% of sewage sludge + 63% of Quartzarenic Neosol or Red-Yellow Latosol. Heavy metal concentration in all substrates was below the limits allowed by CETESB.

Fertilization; forest species; seedling substrate