Amendments and substrates to develop anthroposols for northern mine reclamation

Abstract

Mining and natural resource development in the Canadian north has produced large areas of disturbance and volumes of waste, necessitating reclamation. This study focused on building anthroposols in a greenhouse using waste material from Diavik Diamond Mine. There were six substrates (crushed rock, lakebed sediment, processed kimberlite, and its combinations), seven organic amendments (sewage, soil, peat, Black Earth, biochar, and its combinations), a control, and two nutrient treatments (with and without fertilizer). Substrates and amendments were mixed and seeded with three grass species. Soil properties and vegetation responses were assessed. Substrate structure was a challenge; crushed rock and processed kimberlite had little fine material and lakebed sediment was compacted. Processed kimberlite and sewage had metal concentrations (barium, chromium, cobalt, copper, molybdenum, nickel, selenium, and zinc) above guidelines. Vegetation established on all anthroposols, with plant growth and density greatest in crushed rock, followed by 25% processed kimberlite with 75% lakebed sediment and 100% lakebed sediment. Substrates amended with peat and (or) soil had the greatest plant density and belowground biomass; substrates amended with sewage and sewage-soil had greatest aboveground biomass. Fertilizer had a limited effect. With appropriate amendments, waste materials at the mine showed potential as reclamation soils.

Effects of compost, biochar and ash mixed in till soil cover of mine tailings on plant growth and bioaccumulation of elements: A growing test in a greenhouse

“…Thus, organic amendments are needed for ensuring vegetation establishment in the tailings and in glacienic till, which is the most common cover material on the Nordic mine waste areas. Similar results have been reported also in studies (Dietrich et al, 2017;Drozdowski et al, 2012;Miller and Naeth, 2017). Contrary to our second expectation, the biochar application to the till soil did not affect germination of clover and timothy seeds, which is probably due to the adequate irrigation during germination.…”

Amending mine tailing cover with compost and biochar: effects on vegetation establishment and metal bioaccumulation in the Finnish subarctic

“…Our results are in accordance with earlier studies. In Canada, biochar and sewage sludge in covers enhanced vegetation success on mining waste sites (Dietrich et al 2017 ; Drozdowski et al 2012 ; Miller and Naeth 2017 ). In a highly weathered acidic soil, biochar can increase plant growth, efficiency in N and P use, and vegetation cover along with improved seed germination (Anawar et al 2015 ; Zhu et al 2014 ) because biochar raises soil pH, exchangeable cations, and cation-exchange capacity (Beesley et al 2011 ; Park et al 2011 ).…”

Addition of recyclable biochar, compost and fibre clay to the growth medium layer for the cover system of mine tailings: a bioassay in a greenhouse

“…Successful afforestation of non-acidic (low S level) mine waste areas have been found with at least 20-50-cm-thick topsoil layer in boreal conditions in Canada (Larchevêque et al 2014). Bc and other additives such as peat and sewage sludge mixed in mine covers have also been used to enhance vegetation restoration (Drozdowski et al 2012;Dietrich et al 2017;Miller and Naeth 2017). Compost, clay and new recyclable materials such as dried waste paper sludge (FC) have been somewhat studied as growth media components in mine cover systems and bottom sealing layers (Nurmesniemi and Pöykiö 2006;Nurmesniemi et al 2007;Pöykiö et al 2007;Kuokkanen et al 2008;Kukkonen et al 2011;Raivio 2013;Tuomisto et al 2016).…”