Deficiency of Zn is a common problem in different
regions (Ghandilyan et al., 2012). Optimum soybean
yield can be obtained when Zn and P concentrations
in the soil are greater than extension recommendations
(Anthony et al., 2012a). Han et al. (2011) added that
soybean growth was mostly positively correlated with
Zn fertilizer. Soybean yield increased with Zn
fertilization, even in soils at above critical levels, so
recommendations for Zn need to be revised
(Inocencio et al., 2012).