Reclaimed Well Sites on Salt Affected Soils: Electrical Conductivity and Sodium Adsorption Ratio as Plant Community Response Indicators

Salt affected soils are common worldwide, resulting from natural causes and anthropogenic activities. Saline and sodic soils often occur in association with oil and gas production, impacting soil properties which can impede vegetation growth and development. In Alberta, land reclamation regulations require maintaining a threshold value for electrical conductivity (EC) and sodium adsorption ratio (SAR) to measure reclamation success. A study was conducted to evaluate whether EC and SAR can be used effectively as appropriate indicators for salt affected soil reclamation success. In total, 22 well sites from dry mixed grass and central parkland ecoregions of Alberta were selected to assess soil chemical properties, including EC and SAR from 0 to 1.5 m depth and their impact on vegetation parameters. The study showed that although EC and SAR provide valuable information on general soil health, they are not sufficient to determine salt impacts on reclaimed plant communities or to assess salt affected soils comprehensively. EC and SAR were not satisfactory measures to predict plant survival or general vegetation condition. Sodium, chloride, and potassium could be added to reclamation criteria when EC and SAR do not meet criteria, although vegetation is healthy and productive. The upper 0.30 m of soil had the greatest influence on most vegetation parameters in both ecoregions; thus, reclamation criteria are recommended to focus salt remediation at this depth.