Comparison of four nickel hyperaccumulator species in the temperate climate zone of Central Europe

Abstract

Agromining of Ni is the use of Ni hyperaccumulator plants for extracting Ni. The efficiency of agromining is quantified by the Ni yield, which is the product of harvested biomass and shoot Ni concentration. The present field experiment evaluated the agromining efficiency on an Austrian serpentine soil by comparison of four potential Ni hyperaccumulator plants: Berkheya coddii Roessler, Bornmuellera tymphaea (Hausskn.) Hausskn., Bornmuellera emarginata (Boiss.) Rešetnik and Odontarrhena chalcidica Waldst. & Kit. Additionally, a large-scale plot with O. chalcidica was established in order to gain a representative assessment for agromining in the temperate climate zone of Central Europe. A consecutive three-year planting with O. chalcidica provided a perspective for agromining in the long-run. Nickel yields were clearly highest for O. chalcidica (94.3 kg ha−1) due to highest biomass production (5.93 t ha−1). Shoot Ni concentration did not differ between B. tymphaea (17.1 g kg−1 DW), B. emarginata (17.6 g kg−1 DW) and O. chalcidica (16.0 g kg−1 DW) and had no considerable effect on Ni yields. Berkheya coddii was significantly lowest in biomass production (1.08 t ha−1), shoot Ni concentrations (7.94 g kg−1 DW) and Ni yields (8.54 kg ha−1). Soil concentrations of potentially bioavailable Ni fractions (NiDTPA) were replenished until the next growing season, suggesting that Ni concentrations in shoots will remain constant in consecutive growing seasons. We conclude that O. chalcidica has the greatest potential for agromining on a serpentine soil in the temperate climate zone of Central Europe.