Zinc fertilizers will continue to be used in agriculture to sustain crop yields to meet the demand for food in a growing population. Since Zn deficiency in humans has become a problem of major concern, current fertilizer research programs seek to improve not only yields but also grain Zn concentrations to address both food security and quality. It has been experimentally shown that under Zn-deficient conditions the application of Zn fertilizers to the soil is an effective strategy to increase crop yields, whereas foliar Zn application is highly effective when the goal is Zn bio fortification. Timing foliar sprays is a critical factor that determines the effectiveness of foliar-applied fertilizer in increasing grain Zn concentrations.

Although various sources of Zn are available in the market, the inorganic compounds ZnSO4 and ZnO are the most commonly used Zn fertilizers and for cost, reasons are unlikely to be replaced by other compounds. Zinc sources can be applied alone into the soil, but the incorporation of Zn in macronutrient formulations has become popular as it allows a more uniform distribution of Zn into the soil and eliminates the need for additional field operations. In Zn-enriched fertilizers, the availability of Zn can be affected by the chemical reactions of Zn and the P component of the macronutrient carrier which reduces the water solubility of Zn.