Plant Uptake Factors of As, Cd, and Pb for Corn and Soybeans Cultivated in Brazilian Agricultural Areas Under High-P Fertilization.

Phosphate fertilizers are a potential source of trace elements (TE) in agricultural systems. Such TE may pose a risk to human health if they are transferred to edible parts of plants. The ability of plants to transfer TE to edible parts is estimated by the ratio of TE concentrations on the plant over their concentrations in the soil, i.e., by the plant uptake factor (PUF), which is an essential parameter for risk assessments, since the food chain represents an important route of exposure of TE to humans. This study evaluated PUFs of Cd, Pb, and As for corn and soybeans grown in soils with records of a long-term application of high doses of phosphate (P) fertilizers in Brazil. The PUF for soybeans and corn cultivated in Mato Grosso State decreased in the following order: Cd>Pb>As, which is in agreement with the fact that Cd is the least and As the most retained of the studied TEs in oxidic soils. The PUF of Cd for corn cultivated in Minas Gerais State did not show differences among cultivars.  Soil P content did not affect  the PUF of Cd for corn cultivated in soils receiving different doses of P fertilization in the Brazilian Central Plateau. The results for As and Pb are in agreement, whereas those for Cd  are greater than data reported in the literature for both crops, which are responsible for half of the Brazilian fertilizer demand. Sponsored by FAPEMIG, CNPq, and CAPES.