Soil Amendments to Increase Vegetative Growth on Developing Technosols

Building on previous studies of Technosols manufactured from crushed waste rock and board mill residuals (20:80) for use in mine reclamation, this study investigates the additions of selected soil amendments to improve fertility and soil moisture retention capacity to enhance seedling and transplant survival. This biochamber growth study set for predicted 2030 post-mine closure spring climatic conditions for the Boreal Shield Region north of Lake Superior investigated the suitability of elemental Sulphur (S0), wood boiler ash, N-Rich^R, surface humus forms from stockpiled Gleysolic and Podzolic soils as amendments to promote growth of Annual Ryegrass (Lolium multiflorum). Applications of 10% (v/v) Humic Gleysol Humus Form material and wood ash at 80 t ha-1 promoted maximum root development. Addition of S0 Prills (1.5% w/w) produced the greatest increase in both above and below ground biomass. The blending of N-Rich^R at 34 t ha-1 induced a measured in-situ soil electrical conductivity of 14 uS cm-1 after simulated storm rainfall events (1 cm rainfall hr-1), with bulk through-flow containing high concentrations of dissolved Ca, Mg, K, and low Na. Soil sample analyses illustrated that NRich^R applications provided the highest enrichment of available soil nutrients to support the growth of ryegrass, with chemical analyses highlighting the overall need for amendment application to the manufactured growth media to support healthy vegetative growth.