Soil Properties Influencing Restoration of Oil Access Roads in Western North Dakota.

As part of the United States Forest Service’s (USFS) multiple use management guidelines, roads used to access oil wells on USFS lands must be reclaimed when the wells are no longer producing.  An investigation of chemical and physical soil properties on reclaimed roads as well as nearby undisturbed areas was analyzed in conjunction with vegetation data collected from 2004 to 2006 in the Little Missouri National Grasslands in western North Dakota.  Soil properties influencing reclamation were identified, as well as recognition of soil map units that are more conducive to road reclamation potential.  In addition, soil amelioration techniques that may foster reclamation were identified.  Surface soil samples (0-5 cm) were collected in the summer of 2007 and 2008.  Soils were analyzed for coarse fragments, organic matter, electrical conductivity and sodium adsorption ratio, pH, calcium carbonate equivalent, and soil texture using standard laboratory methods. In addition, infiltration rate and soil hydraulic conductivity were measured in the field using a single ring falling head infiltrometer.  Preliminary results indicate a significant difference (p<0.05) for soil factors such as organic matter, infiltration rate, pH, calcium carbonate equivalent, sand and silt between the disturbed road areas as compared to the undisturbed prairie.  Using canonical correspondence analysis, correlations between soil properties and vegetative communities were examined to understand the relationships between the vegetation and soil, different reclamation techniques, and different seed mixes used by the Forest Service.