Zhang et al. highlighted recently that phosphorus fertilizer application reduces grain Zinc (Zn) concentration by 16.6% for wheat and 20.2% for maize. However, Zn content in grain of wheat and rice increases with increasing P fertilization. They ascribe this effect to a mere ‘dilution effect’ (i.e., same abundance in greater biomass) because grain biomass increases in response to P applications while root Zn uptake efficiency declines. They reckoned that attempts for increasing grain Zn concentration by biofortification should consider these effects carefully.
