Zinc in soil-crop-animal-human health continuum

Abstract

Globally, zinc (Zn) deficiency in soils, and subsequently crops, has emerged as one of the most prevalent among micronutrients, resulting in a severe decline in crop yields and nutritional quality and in adversely affecting animal and human health. Worldwide, more than half of the agricultural soils are inherently deficient in Zn, and the health of about one-third of the global human population is impacted by Zn deficiency. Zinc is an essential micronutrient for animal and human health, and, in the developing world, Zn deficiency has been identified as the fifth cause of disease and death for humans. The World Health Organization (WHO) reports that annually more than 800,000 people, including around 450,000 children under the age of 5, die due to Zn deficiency. Zinc supplementation was frequently associated with boosting immunity against COVID-19 in recent years. Because most of the Zn in animals and humans is derived from soil-grown crops, their source of Zn is highly dependent on plant Zn, especially in crops or fodder; in turn, crop Zn is dependent on available soil Zn levels. This integrated review describes Zn distribution, behavior, and fate in soils and its uptake and role in plants and crop production, as well as in the well-being of animals and humans. It discusses recent findings concerning Zn deficiency in all steps of the human food chain (from soil, to crop, animal, and human), and how it can be addressed through novel Zn fertilizers, soil amendments, and biofortification of Zn.