Zinc (Zn) deficiency is a major health concern in developing countries due to dependency on cereal based diet. Cereals are inherently low in Zn and inevitable use of stressed land has further elevated the problem. The aim of current research was to improve wheat and rice grains grain Zn concentration grown in saline soils through zinc oxide nanoparticles (ZnO-NPs) due to their perspective high availability. The ZnO-NPs were prepared by co-precipitation method and characterized through X-ray diffraction (XRD) and Scanning Electron Microscope (SEM). Two separate pot experiments for wheat and rice were conducted to check the relative effectiveness of ZnO-NPs compared to other bulk Zn sources i.e., zinc sulphate heptahydrate (ZnSO₄·7H₂O) and ZnO. Results showed that salt stress negatively impacted the tested parameters. There was a significant (p ≤ 0.05) improvement in growth, salt tolerance, plant Zn uptake and grain Zn concentrations by Zn application through Zn sources. The ZnO-NPs showed maximum improvement in crops parameters as compared to other sources due to their higher uptake and translocation in plants under both normal and stressed soil conditions. Thus, ZnO nanoparticles proved to be more effective for grain Zn fortification in both tested wheat and rice crops under normal and saline conditions.

Agronomic biofortification is the purposeful utilization of mineral fertilizers to increase the concentration of desired minerals in edible plant parts for enhancing their dietary intake. It is becoming crucial to enhance the dietary intake of K for addressing hidden hunger and related health issues such as cardiac diseases and hypertension. This study was designed to enhance the potassium concentration in edible parts of spinach through its foliar application under saline environment. The salinity levels of electrical conductivity (EC) = 4, 6, and 8 dS m⁻¹ were applied using sodium chloride (NaCl) along with control. The levels of K for foliar sprays were 5 and 10 mM, along with control. The present experiment was performed under two factorial arrangements in a completely randomized design (CRD). After 60 days of sowing, the crop was harvested. Data regarding growth, ionic, physiological, and biochemical parameters, i.e., shoot dry weight, relative water content, electrolyte leakage, total chlorophyll content, tissue sodium (Na) and K concentration, activities of superoxide dismutase (SOD), and catalase (CAT) were recorded and those were found to be significantly (p ≤ 0.05) affected by foliar application of K on spinach under saline conditions. The highest growth, physiological and biochemical responses of spinach were observed in response to foliar-applied K at 10 mM. It is concluded that agronomic bio-fortification by foliar use of K can be a useful strategy to increase tissue K intakes and minimize Na toxicity in the vegetables studied under saline conditions.