Zinc biofortification of wheat through fertilizer applications in different locations of China

► Zinc biofortification of wheat was studied through fertilizer applications. ► Foliar Zn application increased grain and flour Zn density and bioavailability. ► The grain and flour Zn increased extent depends on the rates of foliar Zn application. ► And foliar application is more effective than that by soil Zn application or urea supplementation. ► Foliar Zn application showed regional adoptability to biofortify wheat with Zn. Zinc (Zn) deficiency caused by inadequate dietary intake is a global nutritional problem in human populations, especially in developing countries. Biofortification of wheat and other staple foods with Zn is, therefore, an important challenge and a high-priority research task. In this study, one field experiment was conducted to examine the effects of soil and foliar Zn application with or without foliar urea application on Zn nutrition in whole grain and flour of wheat, and on flour processing traits. A second field experiment was conducted at four locations in China to evaluate the adaptability of foliar Zn and/or urea application on the enrichment of grain with Zn in wheat. The results showed that foliar Zn application was much more effective than soil Zn application in enrichment of wheat grain with Zn. Compared with no foliar Zn application, foliar 0.4% ZnSO 4·7H 2O application resulted in best effect on grain Zn, with 58% increase in whole grain Zn, 76% increase in wheat flour Zn, and up to 50% decrease in the molar ratio of phytic acid to Zn in flour. Foliar Zn application had little effect on flour processing traits including protein concentration, peak viscosity, and dough development time. The second experiment showed that foliar Zn application had reliable adaptability in biofortification of wheat with Zn, while had no yield penalty in regional scale. The results suggest that foliar Zn application represents an effective approach to provide more dietary Zn from wheat-derived products to humans.