Because mining and refining nickel is costly, researchers have developed an alternative method for extracting nickel using Streptanthus polygaloides, a plant that absorbs and stores nickel from the soil as it grows  The researchers incinerated a crop of Streptanthus they grew in nickel-rich soil
By chemically extracting nickel from the ash, they produced 100 pounds of nickel per acre of land at a total cost per pound slightly above that of current mining
It is extremely rare for soil to contain higher concentrations of nickel than the concentrations present in the researchers' experimental plot.