BIOSOLIDS AS SUBSTRATE FOR THE PRODUCTION OF CEIBA SPECIOSA SEEDLINGS

ABSTRACT Biosolids is a problematic residual issue in Brazil and other developing countries, where it is common to discard this material in landfills and/or open dumps. However, biosolids can be recycled in agricultural and forestry activities, considering they have high contents of organic matter and nutrients. Therefore, their application in substrates to produce forest seedlings can be beneficial. The scope of this study is to evaluate substrates with different proportions of biosolids and coconut fiber in the growth and quality of seedlings of Ceiba speciosa (A. St.-Hil.) Ravenna, a native species from South America that is largely used for landscaping and forest restoration. There were studied substrates with proportions varying between 25 to 100% of biosolids and 75 to 0% of coconut fiber to produce seedlings in containers (plastic tubes with 280 cm³). At 120 days after sowing, it was measured the growth, biomass and quality of the seedlings. In general aspects, the higher the proportion of biosolids in the substrate, the higher were the growth, biomass and quality. The biosolids favored the growth in shoot height and biomass more than in diameter and root biomass. Considering the positive results and the possibility of recycling biosolids, it is recommended the use of substrates containing from 50 to 100% of biosolids to produce Ceiba speciosa seedlings in 280 cm³ plastic tubes.