Distribution of Total Hg in North Dakota Soils.

The presence and distribution of mercury (Hg) in the soil profile is a function of anthropogenic deposition and geologic events.  The objective of this study was to determine the distribution of total Hg in surface and subsurface soils in North Dakota.  Samples were taken in 1996 from each of the 53 counties in North Dakota (n = 156) and in 2008 from each of the North Dakota Agricultural Weather Network sites (n = 70).  In addition, soils from the Pembina Gorge area located in northeast North Dakota were also sampled in 2008.  Information regarding the 1996 samples have been previously described by Franzen et al. (2006, Agron. J. 98:1015-1022). Results from the Pembina Gorge samples indicate that surface soils (0-15 cm) have a total Hg concentration ranging from 47 to 64 ng/g across a 20 m landscape position change.  At the 2.4 m depth at the highest landscape positions, total Hg concentrations were as high as 185 ng/g.  The information gained from this research will establish baseline and distribution of total Hg in North Dakota soils.