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Abstract. Mineland reclamation rules in Minnesota require that tailing dams be constructed and vegetated to control wind and water erosion for dam stability, safety, and dust control. Coarse !aconite tailing used in dam construction tend to resist vegetation stabilization due to several adverse edaphic factors, including: 1) alkaline reaction; 2) lack of organic matter; 3) lack of fine texture; 4) low water-holding capacity; 5) low cationexchange capacity; 6) lack of plant-available nutrients, particularly nitrogen and phosphorus; 7) a dark color that absorbs and retains heat; and 8) little or no biological activity. These factors make it difficult to establish and maintain a diverse productive vegetative cover that will meet State standards. The Bureau of Mines implemented a 4x3x3 factorial experiment at Eveleth Mines using four organic amendments (2 municipal solid-waste composts -both windrowed 180-days, composted yard waste, and hemic peat), at 3 levels (22.4, 44.8, and 89.6 Mg ha· 1 ), and 3 fertilizer levels (0, 224, and 448 kg ha· 1 of 18-46-0) arranged in a randomized complete block design. Treatment combinations (36) and controls (3) were assigned to 2.5 by 4 m plots at random. Each treatment and control plot was replicated 3 times. All amendments were incorporated to a depth of 15 cm and the plots were hand seeded using smooth brome (Bromus jnermjs), red fescue (Festuca ru.bra), perennial ryegrass (LoHum perenne), alfalfa (Medicago SJUilrn), and buckwheat (Faeoizyrum escuJentnm) at 15, 8, 7, 8, and 20 kg ha· 1 , respectively. The overall cover on the experimental site was 49 % with cover ranging from zero to 91 %. First-year results show that the main effects of type of organic amendment used, the rate at which the organic residues were applied, and the level of fertilization each had a significant effect on cover. The mean total plant density value on the experimental site was 384 stems m·' and ranged from zero to 790 stems 4 . m.Additional

Mine land reclamation rules in Minnesota require that tailing darns be constructed and vegetated to control wind and water erosion for dam stability, safety, and dust control. Coarse taconite tailing used in darn construction tends to resist vegetation stabilization due to several adverse edaphic factors that make it difficult to establish and maintain a diverse and productive vegetative cover that will meet State standards. The Bureau of Mines, in cooperation with the Minnesota Department of Natural Resources-Division of Minerals, has implemented a series of experiments on coarse taconite tailing to study the effects of various organic residues on the establishment and maintenance of vegetative cover for site amelioration. At each of the tailing darn sites, changes that occurred in.vegetative cover (live vegetation and its litter) as a result of experimental treatment was monitored. At the Minntac site, the total cover (mean of all treatment combinations) on the experimental site was 41 % with cover ranging from zero to 100 %. The type of organic amendment used, the rate at which the organic residues were applied, and the level of fertilization each had a significant effect on cover. The total number of plant species found at the Minntac site, including seeded vegetation, was 18. At the Eveleth Mines site, the total cover on the experimental site was 55 % with cover ranging from zero to 100 %. The type of organic amendment used, the rate at which the organic residues were applied, and the level of fertilization each had a significant effect on cover. Additionally, there were significant interactions between each of the main effects. The total number of plant species found at the Eveleth Mines site, including seeded vegetation was 38.

Abstract. Mineland reclamation rules in Minnesota require that tailing dams be constructed and vegetated to control erosion for dam stability and safety. Coarse taconite tailing used in dam construction tend to resist vegetation stabilization due to several adverse edaphic factors, including: 1) alkaline reaction; 2) lack of organic matter; 3) lack of fine texture; 4) low water-holding capacity; 5) low cation-exchange capacity; 6) lack of plant-available nutrients, particularly nitrogen and phosphorus; 7) a dark color that absorbs and retains heat; and 8) little or no biological activity. These factors make it difficult to establish and maintain a diverse vegetative cover that will meet State standards. The Bureau of Mines implemented a 3x3x3 factorial experiment at United States Steel's Minnesota Ore Operations (Minntac) using 3 compost types (mature composted municipal solid waste · 180-day windrow, intermediate-aged composted municipal solid waste -90-day windrow, and immature composted municipal solid waste -45-day windrow), at 3 levels (10, 20, and 40 Mg ha· 1 ), and 3 fertilizer levels (0, 224, and 448 kg ha' 1 of 18-46-0) in a randomized complete block design. Treatment combinations (27) and controls (3) were assigned to 2.5 by 4 m plots at random. Each treatment and control plot was replicated 3 times.All amendments were incorporated to a depth of 15 cm and plots were hand seeded using smooth brome (Bromus jnermis), red fescue (Festuca ruhra), perennial ryegrass (LoJium perenne), alfalfa (Medicaeo SJl.liya), and buckwheat (Faeop_yrum escuJentum) at 15, 8, 7, 8, and 20 kg ha·', respectively. The overall cover on the experimental site was 34 % with cover ranging from 0 % to 82 %. First-year results show that the main effects of the rate at which municipal solid-waste composts were applied and the level of fertilization each had a significant effect on cover. The mean total plant density value was 296 stems m·'-with a range of 3 to 750 stems m· 2 • . Results indicate that of compost age and the· level of fertilization had a significant effect on total plant density.

Abstract.The purpose for reclaiming mineral related mining waste sites is to stabilize them to prevent wastes from being moved by wind and water. Principal methods used to stabilize mining waste are physical, chemical, and vegetative. The ecological approach used to research stabilization of northern Minnesota coarse taconite tailing is a combination of physical and vegetative stabilization techniques. The Bureau of Mines has implemented a series of unbalanced factorial experiments on two sites based on amendments used, rate of application, and level of fertilization. At both Minntac and Eveleth Mines, total cover has exhibited progressive increases through three growing seasons. Total cover at Minntac has increased from none to 34% the first growing season, 41 % the second growing season, and 56% the third growing season. There are four treatment combinations that are within 12 percentage points of State reclamation requirements. At Eveleth Mines, total cover has increased from none to 49% the first growing season, 55% the second growing season, and 67% the third growing season. There is one treatment combination that exceeds and eight treatment combinations that are within 10 percentage points of State requirements of 90% cover afterthree growing seasons.