Effects of Phosphorus and Iron on the Phytotoxicity of Lettuce (Lactuca sativa L.) in Arsenic-Contaminated Soil.

We investigated that the effect of phosphorus (P) and iron (Fe) on the phytotoxicity of lettuce in arsenic (As)-contaminated soil using response surface methodology (RSM). To stabilize arsenic and supply nutrient, Fe and P were applied, respectively. From a chemical assessment, As extractability was decreased by Fe but increased by P. From a biological assessment, phytotoxicity test, As in lettuce roots was negatively associated with not only root elongation but also P in roots. From a confirmation study, we could verify that the former result was not a passing phenomenon and Fe was necessarily needed to protect secondary pollution by exclusive usage of phosphorus fertilizer.