ABSTRACT
The pressing need to increase the number of seedlings planted annually, as well as the reduced availability of traditional raw materials for the composition of substrates have led to a need of developing studies aimed to evaluate and to provide new materials for the composition of substrates, technically and economically efficient. On this basis, the present study aimed to evaluate the technical feasibility of using components based on renewable coconut fiber (FC), rice hulls (CAC) in different grain sizes, biosolids (BIO) and semi-decomposed pine bark in the composition substrates for the production of seedlings of Eucalyptus benthamii, as well as to assess the correlation between physical and chemical properties of substrates formulated with the quality of seedlings produced. For this, we formulated 41 treatments, which had their physical and chemical properties evaluated, and sowing in tubes made from 55 cm ³. We evaluated the height of the shoot and the stem diameter every 30 days, as well as the dry biomass of shoots and radicial areas, the ease of removal of the cartridge and the aggregation of the roots to the substrate at 90 days. It was found that all renewable materials examined were suitable for the production of seedlings. However, the screening of CAC is not justified when compared with the CAC in its entirety. Measurements of height and diameter prior to final evaluation are unreliable for predicting the outcome. BIO different particle size and CAC had low root aggregation to the substrate. The high levels of salinity, conductivity and pH did not harm the growth of seedlings. Concerning to the physical properties, it was observed that substrates with higher densities and smaller micro-porosity root aggregation provided to the substrate and provided with greater macro-porosity increased growth of shoots and radicial.
Keywords:
biosolids; coconut fiber; rice hulls; pine bark semidecomposta