Zinc deficiency is a major contributor to hidden hunger, affecting billions of people worldwide, particularly in vulnerable populations. Agronomic biofortification with zinc is a promising strategy to increase both crop productivity and the nutritional quality of food, especially in countries like Brazil, where tropical soils are often deficient in this micronutrient. This review analyzes the main technologies applied in the zinc biofortification of edible crops in Brazil, including fertilizer types, application methods, doses, and the use of innovative approaches such as nano-fertilizers and biofertilizers. The results show that the foliar application of zinc sulfate at doses of 600 g ha⁻¹ increased zinc concentration in grains by 25–40% without reducing crop yields. Additionally, the use of zinc nanoparticles increased wheat grain zinc content by up to 30% and biomass production, while biofertilizer application with diazotrophic bacteria raised zinc concentration in maize grains by 12.7–18.2%. These technologies demonstrate potential for enhancing zinc use efficiency and improving the nutritional quality of crops. Standardizing biofortification practices is essential to maximize their impact on food and nutritional security, contributing to the prevention of zinc deficiency in human populations.

Phosphorus (P) availability is currently a limiting factor for agricultural production, especially in tropical soils, and its interaction with cationic micronutrients can significantly affect physiological efficiency and nutrient uptake by plants. Therefore, this study aimed to evaluate the uptake kinetic parameters described by the Michaelis–Menten model (Vmax, Km, and Cmin) for P as a function of the supply of Cu, Fe, Mn, and Zn, as well as the kinetic parameters of Cu, Fe, Mn, and Zn as a function of P supply in cotton (Gossypium hirsutum L.). The experiment was conducted in a greenhouse at the experimental unit of CENA, in Piracicaba, São Paulo, Brazil, using individual pots. Phosphorus concentration and accumulation were reduced only under Fe and Zn deficiency, with reductions of up to 60% in the shoots and 85% in the roots. Zn deficiency caused a drastic reduction in P uptake capacity, with Vmax decreasing from 590 to 50.85 µmol g⁻¹ h⁻¹ (approximately a 12-fold reduction), accompanied by an increase in Cmin (from 269 to 1508 µmol L⁻¹). In terms of micronutrient kinetics, P omission reduced plant growth and affected only Fe and Zn uptake. For Fe, Km increased from 12.82 to 27.31 µmol L⁻¹ and Cmin from 1.03 to 20.51 µmol L⁻¹. For Zn, and Vmax decreased from 0.16 to 0.02 µmol g⁻¹ h⁻¹ (approximately 8-fold), while Cmin increased from 0.08 to 1.56 µmol L⁻¹. These results demonstrate a strong interaction between P, Fe, and Zn, highlighting their regulatory roles in nutrient uptake and providing mechanistic insights into plant nutritional efficiency.