Assessing grain yield, nutrient concentrations, and soil quality in Morocco’s rainfed wheat systems

Wheat (Triticum aestivum L.) underpins food security in Morocco, covering ~3 M ha, over 80% of which is under rainfed. Yet these systems face a dual challenge of low productivity and poor grain micro-nutritional quality, particularly for iron (Fe) and zinc (Zn), key contributors to “hidden hunger” that affects more than two billion people globally. Agronomic biofortification—optimizing fertilizer use, soil management, and rotations—offers a promising, scalable pathway to improve grain nutrient density alongside yield. We conducted a diagnostic survey of 100 rainfed wheat farms across two contrasting regions (continental Fès–Meknès, coastal Rabat–Salé–Kénitra), collecting detailed management data plus paired soil (0–20 cm) and grain samples. Average yield was 2.09 t ha⁻¹, close to the national mean, but only a fraction of biophysical potential. Mean grain protein (8.8%) and micronutrient levels (20.8 mg kg⁻¹ Zn; 46.7 mg kg⁻¹ Fe) were well below bread-making and biofortification targets of >12% protein and 38–50 mg kg⁻¹ Zn, 58 mg kg⁻¹ Fe. Regional comparisons showed similar yields but markedly higher protein, Fe, and Zn in the less alkaline coastal soils, highlighting soil pH as a major determinant of nutritional quality. Soil organic matter and texture had modest effects on yield and micronutrients, while no-till tended to enhance grain protein with similar yields relative to conventional tillage. Village-level K-means clustering revealed three performance types: (i) high yield–moderate quality, (ii) low yield–high micronutrients, and (iii) low yield–high protein, illustrating a consistent yield–quality trade-off consistent with the dilution effect. These findings identify clear leverage points—especially soil chemistry management and context-specific agronomy—for simultaneously closing wheat yield gaps and improving nutritional outcomes in Morocco’s rainfed systems.