S06 - Session P16 - Characterization of biochar produced from pruning residues of different species for use in vegetable and flower production

Authors: Andrea Copetta *, Ornella Arimondo, Ferruccio Pittaluga, Carlo Mascarello, Paolo Mussano, Barbara Ruffoni

In a global tendency to circular economy, the recovery and reuse of plant biomass residues are becoming a primary resource for the development of micro and small nursery farms in mountain areas. The pruning residues of trees, hedges and nursery plants can be used for energy production mainly directed to the heating of rural warehouses and greenhouses, with high environmental compatibility. The process of converting organic material to biochar (pyrolysis) reduces the amount of greenhouse gasses emitted to the atmosphere and locks up the carbon content of the plant material in the biochar. Biochar can be used as soil or substrate conditioner, carbon sequestration, guarantees a high cation exchange capacity with roots and the supply of micro-and macronutrients; thanks to the high porosity it improves soil aeration, water absorption capacity and guarantees an ideal habitat for the development of beneficial microorganisms in the soil. The aim of this work is to compare the characteristics of the biochar obtained from pruning of five different plant species and evaluate their application as soil conditioner for vegetable and flower production. The pruning residues of laurel, privet, lentisk and rosemary were dried in the sun, chipped and the wood chips were dried in the greenhouse. Moreover, a mix of industrial wood chips consisting of beech, chestnut and birch was used as a control. Once dried, the wood chips were sieved to eliminate the dusty part. The five different biochars were produced by pyrolysis, using a gas generator. The weight reduction occurred during the pyrolysis was recorded. Culture tests were carried out in pots on basil, pea and calendula to compare the effects of the biochar produced by the five different plant residues. From the first observations it was obtained that biochar affect the development of plants.