Combined Effect of Arsenic and Phosphorus on Mineral Element Concentrations of Sunflower

Abstract
This study was undertaken to examine the combined effect of soil‐applied phosphorus (P) and arsenic (As) on P, As, potassium (K), calcium (Ca), magnesium (Mg), silicon (Si), iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), titanium (Ti), rubidium (Rb), strontium (Sr), barium (Ba), lantanium (La), and cerium (Ce) concentrations of sunflower plants under glasshouse conditions determined by polarized‐energy‐dispersive x‐ray fluorescence (PEDXRF). Three levels of As (0, 30, and 60 mg kg−1) and four levels of P (50, 100, 200, and 400 mg kg−1) were applied to soil‐grown plants. Increasing levels of both As and P significantly increased As concentrations in the plants. Plant growth was significantly reduced with increased As supply regardless of applied P levels. Arsenic toxicity caused significant increases in the concentrations of Mn, La and Ce, but it decreased K, Ca, Mg, Si, Fe, Zn, Cu, Rb, and Sr concentrations. Applied P increased the concentrations of Ti, Sr, and Ba and decreased Zn and Cu. In conclusion, the use of P fertilizers in As‐contaminated soils should be carefully considered in respect to increased As, Ti, Sr, and Ba availability and reduced Zn and Cu availability.