Compared to KH2PO4, all these phosphates may exhibit very different solubility according to the different bonds between different metal cations. It is influenced by the size of the metal cation and its charge, influencing the reticular energy of the structure . Besides that, the experimental release essays reveal that potassium dihydrogen phosphate exhibits much faster solubilization behavior than calcium or calcium and potassium phosphates. Composed solely of fertilizer components (HPO4 2-/PO4 3-, Ca 2+ and K + ) , the produced potassium calcium phosphates may be classified as smart release fertilizers, since they provide a delay of the bioavailability of P and K and also improve the bioavailability of Ca turning these materials an excellent alternative in these nutrient management. In addition, the solid-state mechanochemical activation allows the reactions to occur in a solvent-free environment , producing no liquid or solid waste in the process, ensuring huge savings during the production process .