Crop biofortification for enhanced nutritional density: Breeding, agronomical, and biotechnological strategies

Abstract Over two billion people worldwide suffer from micronutrient deficiencies, or “hidden hunger,” posing serious health risks, especially to children in low‐ and middle‐income countries. This study reviews biofortification as a sustainable, food‐based strategy to improve the nutritional value of staple crops. It summarizes agronomic, breeding, and biotechnological approaches, their effects on nutrient content, and global adoption. Agronomic techniques, including foliar and soil micronutrient applications and microbial inoculants combined with organic matter, reduce phytate content, enhance nutrient uptake, and improve yield and grain quality. Inoculating cereals and legumes with Azospirillum brasilense alongside compost further increases protein content, nutrient absorption, and stress tolerance. Breeding strategies from traditional selection to genomic and marker‐assisted methods have increased iron, zinc, and provitamin A in rice, cassava, beans, and wheat. Biotechnological innovations, such as Golden Rice and CRISPR‐based genome editing, provide precise, scalable solutions for targeted nutrient enrichment. By 2024, 475 biofortified varieties across 12 staple crops were released in over 40 countries, covering more than 12 million ha and reaching 115 million consumers, including 17.3 million smallholder households. Regional distribution differs: Africa leads in vitamin A‐rich crops and iron beans, Asia in zinc‐biofortified cereals and iron lentils, and Latin America and the Caribbean in iron beans, zinc maize, and vitamin A sweet potatoes. Despite progress, challenges remain, including microbial inoculant stability, field performance variability, regulatory hurdles, and cultural acceptance. An integrated, regionally tailored approach combining agronomic, breeding, and biotechnological strategies is essential to reduce micronutrient malnutrition while supporting soil health and food security.