Biofortification of cereals with zinc and iron through fertilization strategy.

Zinc (Zn) and iron (Fe) deficiencies are well-documented public health issue and an important soil constraint to crop production. Generally, there is a close geographical overlap between soil deficiency and human deficiency of Zn and Fe, indicating a high requirement for increasing concentrations of micronutrients in food crops. Breeding new plant genotypes for high grain concentrations of Fe and Zn (genetic biofortification) is the most cost-effective strategy to address the problem; but, this strategy is a long-term process. A rapid and complementary approach is therefore required for biofortification of food crops with Zn and Fe in the short term. In this regard, a fertilizer strategy (agronomic biofortification) represents an effective way for biofortification of food crops. In this paper, several examples are presented showing that application of Zn fertilizers greatly contribute to biofortification of cereal grains with Zn. By contrast, application of various inorganic and chelated Fe fertilizers remains ineffective for increasing grain Fe concentration. However, improving nitrogen (N) nutritional status of plants promoted accumulation of Fe (and also Zn) in grain. It appears that N nutritional status of plants plays a critical role in biofortification of cereal grains with Zn and Fe.