Iron fortification of food crops through nanofertilisation

Micronutrient deficiencies are a significant cause of malnutrition worldwide, particularly in developing countries, affecting nearly 1.8 billion people worldwide. Agriculture is the primary source of nutrients for humans, but the increasing population and reducing arable lands areas are putting the agricultural sector under pressure, particularly in developing and less developed countries, and calls for intensive farming to increase crop yield to overcome food and nutrients deficiency challenges. Iron is an essential microelement that plays a vital role in plant and human growth, and metabolism, but its deficiency is widely reported and affects nearly one-third of the world population. To combat micronutrient deficiency, crops must have improved nutritional qualities or be biofortified. Several biofortification programs with conventional breeding, biotechnological and agronomic approaches have been implemented with limited success in providing essential nutrients, especially in developing and under-developed countries. The use of nanofertilisers as agronomic biofortification method to increase yields and nutrients, micronutrient availability in soil and uptake in plant parts, and minimising the reliance on harmful chemical fertilisers is essential. Using nanoparticles as nanofertilisers is a promising approach for improving the sustainability of current agricultural practices and for the biofortification of food crop production with essential micronutrients, thus enhanced nutritional quality. This review evaluates the current use of iron nanofertilisers for biofortification in several food crops addressing critical knowledge gaps and challenges that must be addressed to optimise the sustainable application.