Fig. 9: Locations of the trial sites in the meta-analysis.
From: Zinc agronomic biofortification in wheat and its drivers: a global meta-analysis

Yellow shadings represent the regions of wheat production (obtained from http://www.earthstat.org/harvested-area-yield-175-crops/). Blue, green, and red points denote the trial sites where Zn fertilizers are applied to soil, foliage, and soil+foliage, respectively. Source data are provided as a Source data file.