Jan 1, 2020 · New opportunities for a circular economy are created by the utilization of waste biomass, e.g. post-extraction residues that could be enriched with micronutrient ions, such as ions of Cu, Mn, and Zn to produce bio-based micronutrient fertilizers ( Samoraj et al., 2019 ). The concept of new bio-based micronutrient fertilizers also includes other