Use of modelled soil data ranges to explore post-reclamation soil suitability ratings for 30 Alberta soil series

Return to equivalent capability is the principle governing land reclamation in Alberta. However, land capability rating systems are seldom used to determine post-reclamation equivalency in agricultural lands. This study used the Land Suitability Rating System for Agricultural Crops (LSRS) to estimate reclaimed soil profile ratings. Baseline soil data for 30 soil series obtained from the Alberta Soil Layer file were changed to yield synthetic data. Admixture was simulated by mixing 10 equal increments of B horizon (subsoil) into the A horizon (topsoil) to a maximum of 50% of initial A horizon thickness. Subsoil density was changed in 2.5% increments above baseline to a maximum increase of 25%. Admixture effects on texture, organic carbon, and thickness of topsoil and density change in subsoil were quantified across these 10 treatment levels and deductions were calculated with the LSRS. At level 10 in which topsoil consisted of 33% subsoil admixture by volume and subsoil density had increased by 25%, capability declined from one to five classes below baseline. Future work will employ quantitative field data to explore the accuracy of these findings and to test the hypothesis that current assessment methods may be unreliable for confirming a return to equivalent capability.