Zinc (Zn) is an essential trace element for humans (Krężel & Maret 2016), and about a third of the world’s population is estimated to be at risk of Zn deficiency (Li et al. 2015). The usefulness of a Zn fertilizer will depend on its bioavailability in soil (Cakmak & Kutman 2018). However, 90% of inorganic Zn fertilizers (ZnSO4·7H2O) applied to calcareous soils quickly become unavailable to plants due to the physicochemical properties of soil, including high pH and high levels of carbonate (Lu et al. 2012).