Influence of zinc and iron enrichment on nutritive quality of biofortified wheat grain

Abstract:

Micronutrient deficiency in cereal grains affects over two billion people globally, and agronomic biofortification through targeted soil and foliar application of zinc and iron offers a direct route to raise grain nutrient density without changing farmer cropping patterns. A two-season field experiment (winter 2022-23 and 2023-24) was conducted at Çukurova University, Adana, to evaluate how graded doses of ZnSO₄ (0, 5, 10, 15, 20, and 25 kg ha⁻¹) combined with FeSO₄ (0, 10, and 20 kg ha⁻¹) and a foliar Zn-EDTA spray at booting affected grain zinc, iron, protein, and phytate concentrations in wheat variety Bezostaja-1. Results showed that soil ZnSO₄ at 20 kg ha⁻¹ plus FeSO₄ at 10 kg ha⁻¹ with one foliar spray raised grain Zn from 22.4 to 47.3 mg kg⁻¹ and grain Fe from 31.2 to 40.1 mg kg⁻¹, while grain protein rose by 1.3 percentage points. The phytate-to-zinc molar ratio dropped from 28.6 to 16.4, crossing the bioavailability threshold of 18. These data indicate that a combined soil-plus-foliar strategy can meaningfully improve the nutritive quality of wheat grown on calcareous soils typical of dryland farming regions.