Ahlgren, J., Djodjic, F., Wallin, M. 2011. Barium as a Potential Indicator of Phosphorus in Agricultural Runoff.  Journal of Environmental Quality. Volume 41, Number 1. Pages 208-216

agriculture, nutrients, runoff, Phosphorus

https://dl.sciencesocieties.org/publications/jeq/abstracts/41/1/208

The objective of this study was to determine whether or not trace elements distributed in surface water could be used to trace sources of contamination. According to the results of this study, barium is the most fit to act as a tracer for an individual source of human contamination of surface waters.