Produção de mudas de Corymbia citriodora E Hymenaea courbaril adubadas com efluente de abate de bovinos desinfetado com ácido peracético

Abstract

Seedling production is increasing in the country, both for commercial purposes and for native forest restoration. To obtain satisfactory results in the field, it is necessary that the seedlings produced are of high quality. Fertilization with commercial fertilizers contributes to the production of healthy and vigorous seedlings; however, the use of alternative materials, found in the form of waste, such as effluents, can be applied as fertilizers for seedling production in a more sustainable and economical way. Therefore, the objective of this work was to evaluate the potential of bovine slaughterhouse effluent disinfected with peracetic acid (PAA) as a nutrient source in nurseries and to compare it with the commercial fertilizer Monoammonium Phosphate (MAP). Disinfection was necessary to inactivate pathogenic microorganisms in the effluent, using a non chlorinated disinfectant with a low residual concentration, PAA. For this study, the experiment was implemented in a randomized block design (RBD), with 5 treatments (Control, MAP, and 3 effluent dosages) with 4 replications for two forest species: Eucalyptus (Corymbia citriodora) and Jatobá (Hymenaea courbaril). The variables evaluated in the seedlings were height and stem diameter every 30 days for a period of 150 days; and at the end of the experiment, physicochemical analyses of the substrate and seedlings (aerial part and root) of all treatments were performed. After planting the seedlings, an ecotoxicological evaluation of the substrate was also carried out using the bioindicator Eisenia fetida (earthworm) through the escape test. The results showed that C. citriodora exhibited increased growth with the application of the effluent, Treatment T3 demonstrated better performance than the control in terms of total fresh mass and root fresh mass. And in the evaluation of height and stem diameter, T3 and T5 differed statistically from the control but significantly less than with the commercial fertilizer. While H. courbaril did not show a difference in development between the treatments. C. citriodora showed a higher plant nutritional content than H. courbaril, however, at the end of the study, the substrates presented a similar chemical composition. Regarding the ecotoxicological evaluation, the substrate that received the C. citriodora seedlings corresponded to a more attractive habitat for earthworms, which may a possible potential for the recovery of contaminated soils.