Avaliação agronômica de resíduos orgânicos urbanos e mexilhão dourado como substratos alternativos na produção de mudas de Eucalyptus dunnii maiden

Abstract

Of the various components necessary to obtain high quality seedlings, the substrate stands out. In the composition of these, organic residues available in the region can be used. In this context, the objective of this work was to evaluate the physical and chemical parameters of compounds from the composting and vermicomposting processes, produced from urban organic waste and golden mussel (Limnoperna fortunei), as well as to evaluate the growth of Eucalyptus seedlings dunnii Maiden, in nursery and field, in substrates and alternative fertilizers formulated from organic compounds produced by both techniques. For the formulation of the substrates, initially, composting and vermicomposting were carried out from urban waste: tree pruning residues + vegetable residues (fruit and vegetable residues) + biosolid and golden mussel. Compounds and vermicomposts were selected according to the lowest rate of toxic heavy metals found in the final compounds evaluated. From the compounds produced, the substrates were formulated, in different concentrations of organic compost (C) and commercial substrate (SC) and as a source of basic fertilization: organic nitrogen fertilization (vermicompost (V)) and commercial fertilizer (AC ): T1: 100% C+ V; T2: 75% C + 25% SC + V; T3: 50% C + 50% SC + V; T4: 25% C + 75% SC + V; T5: 100% SC + V; T6: 100% C + AC; T7: 75% C + 25% SC + AC; T8: 50% C + 50% SC + AC; T9: 25% C + 75% SC + AC; T10: 100% SC + AC. The physical and chemical characterization of the substrates was carried out and the sowing of E. dunnii began in 50 cm³ tubes. For the evaluation of seedlings in the nursery, the completely randomized design (DIC) was used, in a split-plot scheme in time: 30, 60 and 90 days after emergence. The quality of the seedlings was evaluated by the main morphological parameters: shoot height (H), collar diameter (D), H/D ratio, root length, root dry mass, shoot and total, leaf area and number of leaves, Dickson's quality index, ease of removal from the tube and aggregation of the roots to the substrate. In the field, the design used was in DBC, in a splitplot scheme in time: (at planting, 15; 30; 45; 60; 75 and 90 days after planting - DAP), with 2 replications. The results showed that the compounds produced respected the limits established by IN No. 25/2009 of MAPA, and by CONAMA Resolution No. 375/2006. The presence of the golden mussel did not present toxicity to the organic compounds studied. The seedlings, in the nursery, presented values of H and D that increased over the evaluation times, and the best performance in the field, with the greatest increase in H and D, at 90 DAP, were the seedlings produced in substrates with 75% of organic compost+25% commercial substrate+commercial fertilizer. The use of composting and vermicomposting were viable, sustainable and low-cost alternatives for the proper disposal of organic waste from Foz do Iguaçu, in the production of E. dunnii seedlings.