In situ amelioration of sodic minespoil with chemical amendments and crop management. I. Soil chemical properties

Sodic minespoils, which often have undesirable properties that limit plant growth, may be ameliorated by chemical amendments. The objective of this study was to determine the effectiveness of sulfur and gypsum amendments in conjunction with crop management (summerfallow/barley rotation and continuous forage) in reducing the sodicity of a calcareous, sodic, sandy loam minespoil at the Highvale coal mine, west of Edmonton, Alberta. Amendments were added in chemically equivalent amounts to theoretically ameliorate the uppermost 35 cm of the spoil. Topsoil (20 cm) overlay both the amended and unamended spoil. Soil chemical parameters were measured to determine amendment effectiveness in an upper amended (20–35 cm depth interval from the surface), a lower amended (40–55 cm) and an upper unamended layer (55–70 cm), all within minespoil.Both sulfur and gypsum effectively reduced minespoil sodicity. The ameliorative effect on SAR occurred within 3 mo with gypsum amendment, but was slower with sulfur. Both amendme...