%0 Journal Article %T Organic Amendments and Earthworm Addition Improve Properties of Nonacidic Mine Tailings %A P. M. Rutherford %A J. M. Arocena %J Applied and Environmental Soil Science %D 2012 %I Hindawi Publishing Corporation %R 10.1155/2012/395964 %X In many mined areas, lack of topsoil limits conversion of disturbed landscapes to former or other productive uses. We examined the use of biosolids (10 or 20% by dry mass), with or without sawdust, pulp sludge, and the contribution of an earthworm species (Dendrobaena veneta) to improve the properties of nonacidic mine tailings. Pulp sludge more rapidly immobilized excessive concentrations from biosolids early in the study; however, total mineral N concentrations were similar in pulp sludge and sawdust treatments by week 29. Although -N concentrations were generally greater in treatments with earthworms, these trends were not statistically significant ( ). In general, Bray P concentrations were greater in the presence of earthworms. Soil thin sections showed that earthworms mixed organic residues into elongated spherical units within mine tailings. Organic residues in combination with earthworm addition may improve the chemical and microstructural properties of non-acidic mine tailings, producing a substrate conducive for plant establishment. 1. Introduction Mining operations around the world produce large quantities of residuals such as tailings, overburden, and waste rock. Past mineral extractions in the Sierra de Cartagena (SE Spain) for >2,500 years left behind large volumes (i.e., usually 700,000¨C900,000£¿m3 per deposit) of wastes composed of overburden rocks and tailings [1]. A copper and gold mine in northern British Columbia (Canada) generated nearly 25 million tonnes of milled waste rock in 2007 [2]. In Canada and other jurisdictions, industry is required to convert disturbed landscapes to former or other productive uses following mine extraction and processing activities. High-quality topsoil is often limiting at mine sites, so mines often need to utilize on-site substrates (such as mine tailings) to create mine soils for reclamation activities. Establishment of vegetation is key to reclamation of mine tailings and other residuals [2¨C5]. Plant cover minimizes the dispersion of particulate matter and contaminants through wind and water erosion, and improves the aesthetic value of unvegetated landscapes [6, 7]. However, mine soils require suitable physical and chemical properties in order to support the growth of plants and associated soil organisms. Tailings are typically fine sands low in organic matter and plant available macronutrients such as N and P. Various industrial, environmental, and municipal waste treatment facilities generate organic materials that can be added to mine residuals to increase soil organic matter (SOM) and/or nutrient %U http://www.hindawi.com/journals/aess/2012/395964/