BIOSOLIDS AS SUBSTRATE FOR THE PRODUCTION OF Ceiba speciosa SEEDLINGS

Abstract

Biosolids is a problematic residual in Brazil and other developing countries, where is common to discard this material in landfills and/or open dumps. However, biosolids can be recycled in agricultural and forestry activities, considering the high contents of organic matter and nutrients in their composition. Therefore, their application in substrates for the production of forest seedlings can be beneficial. The aim of this study was 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 for the production of seedlings in containers (plastic tubes with 280 cm³). At 120 days after sowing the seedlings were evaluated considering growth, biomass and quality. In general aspects, the higher the proportion of biosolids in the substrate, higher was the growth, biomass and quality of seedlings. 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 utilization of substrates containing between 50 and 100% of biosolids to produce Ceiba speciosa seedlings in 280 cm³ plastic tubes.