The use of rare earth elements (REEs) to investigate soil erosion has been expanding in recent years due to strong affinity of REEs to soils, the absence of REEs from most U.S. soils and the ability to accurately detect REEs at low concentration using mass spectroscopy. This study seeks to assess the potential for using REEs to trace the fate of land applied manure. Two methods of labeling manures with REEs are compared: feed supplementation vs. direct mixing with manures. Rainfall simulation experiments are used to assess the fate of REEs in poultry manure applied to packed runoff boxes.