Composted sewage sludge as an alternative substrate for forest seedlings production

Author(s)

Gabira, Monica Moreno ^[1] ; Gomes da Silva, Richardson Barbosa ^[2] ; de Almeida Prado Bortolheiro, Fernanda Pacheco ^[2] ; D'Andrea Mateus, Caroline de Moura ^[2] ; Villas Boas, Roberto Lyra ^[2] ; Rossi, Sergio ^{[3, 4]} ; Girona, Miguel Montoro ^{[5, 6]} ; da Silva, Magali Ribeiro ^[2]

Affiliation

^[1] Fed Univ Parana UFPR, Forestry Sci Dept, Curitiba, Parana - Brazil

^[2] Sao Paulo State Univ UNESP, Dept Forest Sci Soils & Environm, Botucatu, SP - Brazil

^[3] Univ Quebec Chicoutimi UQAC, Dept Sci Fondamentales, Chicoutimi, PQ G7H 2B1 - Canada

^[4] Chinese Acad Sci, South China Bot Garden, Guangdong Prov Key Lab Appl Bot, Key Lab Vegetat Restorat & Management Degraded Ec, Guangzhou - Peoples R China

^[5] Univ Quebec Abitibi Temiscamingue UQAT, Inst Rech Forets, Grp Rech Ecol MRC Abitibi, Amos, PQ J9T 2L8 - Canada

^[6] Univ Huelva, Grp Anal & Planificac Medio Nat, Dr Cantero Cuadrado 6, Huelva 21004 - Spain

• Document type: Journal article
• Source: IFOREST-BIOGEOSCIENCES AND FORESTRY; v. 14, p. 569-575, DEC 2021.
• Web of Science Citations: 0

Abstract

The production of forest seedlings with adequate morphological and physiological characteristics is essential for the success of plantations. Substrates and irrigation are the major factors determining seedlings' growth. Substrates made of urban and agricultural residues are a sustainable alternative to peatbased substrates. In this study, we evaluated how composted sewage sludge substrates affect the growth and gas exchange in seedlings of Cedrela fissilis Vell. Seedlings were produced under daily irrigation depths of 6, 9, and 12 mm, and on different substrates. The substrates were based on sewage sludge composted with Eucalyptus bark or sugarcane bagasse, and a commercial substrate based on peat, involving a double factorial design with 12 treatments (3 irrigation depths x 3 substrates). Both physical and chemical characteristics of substrates were analyzed, and morphological traits and gas exchanges of seedlings were measured. Sewage sludge-based substrates presented different characteristics according to the material it was mixed. Eucalyptus bark provided higher bulk density (0.19 g cm-3) and lower total porosity (75%) to the substrate, while sugarcane bagasse increased macroporosity up to 60%. Seedlings produced in sewage sludge-based substrates presented a height up to 17.8 cm and stem diameters of between 8.39-10.29 mm. Higher shoot and root dry mass was obtained in sewage sludge-based substrates with irrigation depth of 9 mm, which were 3.71 and 2.01 g, respectively. Photosynthetic carbon assimilation varied between 2.26 and 3.23 mu mol CO2 m-2 s-1, and water use efficiency varied from 2.058 to 3.395 mu mol CO2 (mol H2O)-1, with the highest values being obtained in seedlings produced in sewage sludge-based substrates with irrigation depth of 6 mm. Our results demonstrate that sewage sludgebased substrates are an efficient alternative to commercial peat-based substrates for seedling production. (AU)

• FAPESP's process: 13/50413-0 - Composting sewage sludge: evaluation of process, resulting product and costs
• Grantee: Roberto Lyra Villas Boas
• Support Opportunities: Research Grants - Research Partnership for Technological Innovation - PITE