Rare Earth Elements in Oxidic Soils With High Inputs of Phosphate Fertilizers.

The use of rare earth elements (REE's) in agriculture has received great attention in recent years, mainly due to the intensive application of phosphate fertilizers, a REE-containing agricultural input that can cause increased levels of these elements in soils. The present study aimed to analyze and quantify REE's in agricultural soils with a record of long-term application of high rates of phosphate fertilizers in Brazil. The work was developed with soil samples collected in a field experiment that has received application of high doses of phosphate fertilizers in the last 8 years, as well as in a control area (soil with native vegetation). Lanthanum (La), Cerium (Ce), Dysprosium (Dy), and Neodymium (Nd) were the main REE's identified in agricultural soils, whereas only La and Ce could be quantified in the control soil. Irrespective of the applied dose, adding phosphate fertilizer to the soils during the eight years of application increased the original soil concentrations of La and Ce by 50%. Sponsored by FAPEMIG, CNPq, CAPES, and Vale.