Sewage sludge compost for initial cultivation of eucalyptus

Abstract

This study evaluated the feasibility of sewage sludge compost obtained from a sewage treatment plant as an alternative “Class D” organic fertilizer for the initial cultivation eucalyptus. The experiment was conducted in a greenhouse at CCA - UFSCar, Araras, SP. Cultivation occurred in 11 L pots for 75 days. We adopted a completely randomized design, with five treatments and seven repetitions. The tests considered a control treatment with no fertilization, three treatments with sewage sludge compost addition (25%, 50%, and 75% of the pot volume) and a treatment with conventional mineral fertilizers, all in sandy soil. At the end of the experiment, plant relative growth rate and dry mass were evaluated and submitted to analysis of variance, followed by a Tukey test at 5% probability. Treatments with fertilization had a greater relative growth rate than the control; however, we found no difference between mineral and organic fertilization. Plant dry mass was higher in the treatment with 50% of the pot filled with organic fertilizer. Thus, we conclude that the tested sewage sludge compost is a potential substitute for conventional mineral fertilization for the initial cultivation of eucalyptus.