Zinc nutrition for high productivity and human health in intensive production of wheat

The role of cereal grain zinc (Zn) in human health has been intensively studied in dietary structure, but limited information is available on the transfer of Zn from soil to crop grain for wheat grown in the intensive production system, especially the effect from management practices such as applications of fertilizer Zn, nitrogen (N) and phosphorus (P). Using wheat as a model crop in the intensive agriculture system, we have found that more Zn supply is needed to achieve the high yield goal. The critical levels for soil DTPA-Zn and shoot Zn concentration at anthesis for maximum grain yield are identified as 1.98 and 29.4 mg kg− 1, which were greater than those of the previous reports. Increasing N supply improved wheat Zn uptake due to increased root length and surface area. In contrast, fertilizer P application significantly decreased wheat Zn uptake, which was mainly attributed to the reduction of root colonization by arbuscular mycorrhizal fungi. Applying strategies such as foliar and soil application of Zn fertilizers can enhance grain Zn bioavailability, depending on the application method and the amount of available soil Zn. For Zn biofortification, foliar application of Zn has great superiority due to its benefits on grain Zn, low cost, and high adaptation to environment and crop production systems. In conclusion, N and P fertilizations can be optimized to combine with Zn fertilizer application as a double-win strategy to simultaneously achieve high grain yield and grain Zn bioavailability for wheat grown in the intensive production system.