Cold Lake Topsoil Depth Experiment

A five-year field experiment was conducted at Cold Lake Operations to assess the impact of reduced topsoil replacement depth and soil amendments on vegetation performance. Twelve plots were established across four treatments: 80% topsoil (control), 50% topsoil, and 50% topsoil with either peat or biochar amendments. The project aimed to determine if reduced topsoil depth could still support successful reclamation and whether amendments like biochar and peat could enhance vegetation recovery. Sampling included vegetation health, species diversity, and detailed soil analyses using technologies like PRS® (Plant Root Simulator) probes for nutrient supply rates.

The results of this field study indicated that all treatments met reclamation thresholds, with biochar-enhanced plots showing promising vegetation performance and lower weed richness despite having the lowest total vegetative cover. Peat amendments exhibited higher zinc concentrations, while PRS® probe assessments revealed no significant nutrient differences across most treatments. The study validated that alternative soil amendment strategies, particularly biochar, can potentially offset reduced topsoil volumes. Biochar may be a valuable reclamation in areas where full topsoil recovery is not feasible.