An Innovative Agro-Forestry Supply Chain for Residual Biomass: Physicochemical Characterisation of Biochar from Olive and Hazelnut Pellets

Concerns about climate change and food productivity have spurred interest in biochar,a form of charred organic material typically used in agriculture to improve soil productivity and asa means of carbon sequestration. An innovative approach in agriculture is the use of agro-forestrywaste for the production of soil fertilisers for agricultural purposes and as a source of energy.A common agricultural practice is to burn crop residues in the field to produce ashes that canbe used as soil fertilisers. This approach is able to supply plants with certain nutrients, such asCa, K, Mg, Na, B, S, and Mo. However, the low concentration of N and P in the ashes, togetherwith the occasional presence of heavy metals (Ni, Pb, Cd, Se, Al, etc.), has a negative effect onsoil and, therefore, crop productivity. This work describes the opportunity to create an innovativesupply chain from agricultural waste biomass. Olive (Olea europaea) and hazelnut (Corylus avellana)pruning residues represent a major component of biomass waste in the area of Viterbo (Italy). In thisstudy, we evaluated the production of biochar from these residues. Furthermore, a physicochemicalcharacterisation of the produced biochar was performed to assess the quality of the two biocharsaccording to the standards of the European Biochar Certificate (EBC). The results of this study indicatethe cost-effective production of high-quality biochar from olive and hazelnut biomass residues.