Crop Biofortification for Sustainable Food Systems: An Integrative Review of Soil Processes, Plant Physiology and Molecular Approaches

Micronutrient deficiencies, collectively known as hidden hunger, affect more than two billion people worldwide and remain a major challenge for sustainable agriculture, global food security and human nutrition. Crop biofortification has emerged as a sustainable agricultural strategy to enhance the concentration and bioavailability of essential micronutrients in edible plant tissues while reducing reliance on post-harvest fortification and dietary supplementation. This review provides an integrated analysis of the soil, plant physiological, agronomic and molecular processes governing biofortification efficiency in agricultural systems. Particular emphasis is placed on how soil formation, mineralogy, nutrient speciation, organic matter and rhizosphere interactions regulate micronutrient availability, root uptake, translocation and accumulation in crops. The review further examines plant physiological mechanisms involved in nutrient acquisition and partitioning, together with the contribution of beneficial microorganisms, precision agriculture and digital technologies to improving nutrient-use efficiency under diverse agricultural conditions. Conventional breeding, agronomic biofortification, transgenic approaches and genome-editing technologies are critically evaluated as complementary strategies for developing nutrient-enriched and climate-resilient crop varieties. Particular attention is also given to nutrient bioavailability, post-harvest stability and consumer acceptance, which ultimately determine the nutritional effectiveness of biofortified crops. Furthermore, the review discusses how climate change modifies soil properties, plant physiology and crop productivity, thereby influencing micronutrient availability, nutrient accumulation and the long-term effectiveness of biofortification programmes. By integrating advances in soil science, plant physiology, agronomy and molecular biology, this review identifies current challenges, knowledge gaps and future research priorities for developing resilient biofortification strategies capable of supporting sustainable agricultural systems and improving global nutritional security.