Integrated Use of Zinc and Nitrogen for Enhancing Grain Quality and Productivity of Wheat

Abstract

Wheat (Triticum aestivum L.), a staple providing 20% of global calories and protein, faces challenges from micronutrient deficiencies like zinc (Zn), contributing to "hidden hunger" affecting over 2 billion people. This review examines the synergistic integration of nitrogen (N) and zinc fertilizers to enhance wheat productivity and grain quality. Nitrogen drives biomass accumulation, chlorophyll synthesis, and protein formation, while zinc acts as a cofactor for 300+ enzymes, stabilizing membranes and boosting antioxidant defenses against stresses. Combined application via soil incorporation (5–10 kg Zn/ha) and foliar sprays (0.5–2% ZnSO4) improves photosynthetic efficiency, delays senescence, increases grain Zn concentration (20–50% biofortification), protein content (up to 15%), and yield (10–30%) under diverse conditions. Agronomic strategies address soil pH, organic matter interactions, and timing (e.g., booting stage foliar), mitigating deficiencies in alkaline calcareous soils. Environmental factors like drought amplify synergies, with integrated use reducing oxidative stress via enzymes like SOD and CAT. This approach offers a sustainable path for nutritional security, emphasizing balanced fertilization to optimize harvest index and resource efficiency in high-yielding systems.