Abstract: The invention includes methods for (1) extracting metals from soil by the use of plants that extract and accumulate the metal and adding bacteria to the soil that enhances the ability of the plants to extract the metal, and (2) preparing soil for extraction of a metal by plants by adding bacteria to the soil that enhances the ability of plants to extract the metal. It is preferred that the plants be planted in the soil as seeds and that the bacteria added to the soil is also added to the seeds prior to planting.

Abstract: The recovery of nickel, cobalt and other metals by phytomining is described. Plants of the Alyssum genus are grown in nickel rich soil. The uptake of nickel is enhanced by maintaining specific soil conditions, including a concentration of calcium between (but not including) 0.128 mM an 5.0 mM and an acidic pH. Ni uptake may be further enhanced by maintaining a ratio of exchangeable Ca/Mg of 0.16-0.40. Uptake may be further enhanced by addition of chelating agents and ammonium based fertilizers.

Abstract: Nickel/cobalt, as well as platinum and palladium metal family members are recovered from soil by growing Brassicaceae plants, specifically Alyssum in soil containing nickel/cobalt as well as other metals. The soil is conditioned by maintaining a low pH, low calcium concentration, and the addition of ammonium fertilizer and chelating agents thereto. Nickel accumulation on the order of 2.5 percent or better in above-ground tissues is achieved, which permits recovery of the metal by harvesting the above-ground plant materials, drying, and then combusting the same, to oxidize or vaporize organic materials and recover the metals sequestered therein at 10-20 fold higher concentrations than in the soil, in a form which can be used in conventional Ni refinery or smelting operations.

Abstract: Nickel/cobalt, as well as platinum and palladium metal family members are recovered from soil by growing Brassicaceae plants, specifically Alyssum in soil containing nickel/cobalt as well as other metals. The soil is conditioned by maintaining a low pH, low calcium concentration, and the addition of ammonium fertilizer and chelating agents thereto. Nickel accumulation on the order of 2.5 percent or better in above-ground tissues is achieved, which permits recovery of the metal by harvesting the above-ground plant materials, drying, and then combusting the same, to oxidize or vaporize organic materials and recover the metals sequestered therein at 10-20 fold higher concentrations than in the soil, in a form which can be used in conventional Ni refinery or smelting operations.