title: Phytotoxicity of nickel in a range of European soils: influence of soil properties, Ni solubility and speciation.
abstract: We investigated the influence of soil properties on Ni toxicity to barley root and tomato shoot growth, using 16 European soils. The effective concentration of added Ni causing 50% inhibition (EC(50)) ranged from 52 to 1929mgkg(-1) and from 17 to 920mgkg(-1) for the barley and tomato test, respectively, representing 37- and 54-fold variation among soils. Soil cation exchange capacity was the best single predictor for the EC(50). The EC(50) based on either the Ni concentration or free Ni(2+) activity in soil solution varied less among soils (7-14 fold) than that based on the total added Ni, suggesting that solubility of Ni is a key factor influencing its toxicity to plants. The EC(50) for free Ni(2+) activity from the barley test decreased with increasing pH, indicating a protective effect of protons. The results can be used in the risk assessment of Ni in the terrestrial environment.
authors.affiliation: Agriculture and Environment Division, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK.
authors.forename: Corinne P
authors.initials: CP
authors.lastname: Rooney
authors.forename: Fang-Jie
authors.initials: FJ
authors.lastname: Zhao
authors.forename: Steve P
authors.initials: SP
authors.lastname: McGrath
mesh_terms: D000538:Aluminum Silicates; D001682:Biological Availability; D002118:Calcium / Q000032:analysis; D002412:Cations / Q000737:chemistry; D000077215:Clay; D004305:Dose-Response Relationship, Drug; D001467:Hordeum / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D018551:Solanum lycopersicum / Q000737:chemistry*; D008274:Magnesium / Q000032:analysis; D009532:Nickel / Q000493:pharmacokinetics / Q000633:toxicity*; D018517:Plant Roots / Q000737:chemistry; D018520:Plant Shoots / Q000737:chemistry; D012987:Soil / Q000032:analysis; D012989:Soil Pollutants / Q000493:pharmacokinetics / Q000633:toxicity*; D012995:Solubility
chemical_list: D000538:Aluminum Silicates; D002412:Cations; D012987:Soil; D012989:Soil Pollutants; D009532:Nickel; D008274:Magnesium; D002118:Calcium; D000077215:Clay