The biochar used in our experiment (BioDea ® ) was produced (by BioEsperia srl, Arezzo, Italy) through pyrolysis at temperatures ranging from 600 to 650 °C, using a mixture of agricultural woody residues, (i.e., Castanea sativa Mill., Robinia pseudoacacia L., Fraxinus ornus L., Alnus glutinosa (L.) Gaertn., and Quercus robur L.). Subsequently, the biochar was mechanically collected, resulting in a product with minimal ash content and a high concentration of organic carbon. Finally, the biochar was finely ground and put into an aqueous solution to allow for its application by fertigation in crop fields. The chemical characteristics of the used biochar are reported in Table 1.