British Columbia Mine Reclamation Symposium

Revegetation of saline land caused by potash mining activity Thorpe, Mark B.; Neal, Dick, 1943-

Abstract

Potash mining in Saskatchewan produces 20 million tonnes of waste salt (NaCl) each year. The salt is stored in surface piles which are primarily eroded by precipitation. The resulting brine is contained by a system of dykes but seepage through the dykes has salinized adjacent areas at most mines sites. Our study investigated ways of revegetating a severely salinized area at one mine. Two 30 cm deep surface amendments, topsoil and sewage sludge, were applied to the area and salt and water movements were monitored in the amendments for three years. Topsoil became severely salinized during the first summer and all the seeded grasses growing on it were killed. Sewage sludge sustained vegetation for three years. A greenhouse column experiment indicated that surface evaporation was the key factor determining salt movement into the two amendments. Field and greenhouse results were accurately simulated by the Trasee/Tracon computer model (r² values > 0.86 for sewage sludge). The model was used to simulate salt movement into different depths of amendments under various microclimatic conditions in order to assess the long-term suitability of the amendments to support vegetation.

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