After 7-d of growth, plant biomass was determined after drying in oven at 80 °C for 2 d. To determine the role of P in enhancing plant growth, the dried plant samples were digested using H2SO4/H2O2 and was analyzed for P by modified molybdenum blue method (Ghosh et al., 2011). Total Fe concentration in the plant biomass was measured in the same extracts using inductively-coupled plasma emission spectroscopy (PerkinElmer 5300DV, Waltham, MA) via EPA Method 2007.