title: Metal uptake of tomato and alfalfa plants as affected by water source, salinity, and Cd and Zn levels under greenhouse conditions.
abstract: Irrigation with wastewater is a promising option to improve crop yields and to reduce pressure on freshwater sources. However, heavy metal concentrations in wastewater may cause health concerns. A greenhouse pot experiment was conducted in order to determine cadmium (Cd) and zinc (Zn) concentrations in sandy soil and plant tissues of tomato (Lycopersicon esculentum L.) and alfalfa (Medicago sativa L.). A 2 × 2 × 4 × 2 factorial treatment arrangement was utilized. Two water sources, fresh (FW) or treated wastewater (TWW), at two salinity levels (1 and 3 dS m(-1)) containing different levels of Cd and Zn were used. Samples were collected after a 90-day growth period. It was observed that the growth of both plants was depressed at the highest metal level (L3). Metal accumulation in plant parts increased with the increase of metal concentration and salinity in irrigation water. At low salinity, water source was the main factor which controlled metal accumulation, whereas, at high salinity, chloride appeared to be the principal factor controlling metal uptake regardless of water source. Metal translocation from roots to shoots increased in TWW-irrigated plants, even in the controls. Tomatoes accumulated Cd up to and above critical levels safe for human consumption, even though Cd concentration in irrigation water did not exceed the current recommended values. Therefore, food production in sandy soils may well pose a health hazard when irrigated with TWW containing heavy metals. Complexation with dissolved organic compounds (DOC) in TWW may be to be the principal factor responsible for increased metal uptake and transfer at low salinity, thereby increasing the risk of heavy metal contamination of food and forage crops.
authors.affiliation: Department of Natural Resources and the Environment, Faculty of Agriculture, Jordan University of Science and Technology, P.O. Box 3030, Irbid, 22110, Jordan. mamoun@just.edu.jo.
authors.forename: Mamoun A
authors.identifier: http://orcid.org/0000-0002-0901-6506
authors.initials: MA
authors.lastname: Gharaibeh
authors.affiliation: Department of Soil Science/Soil Ecology, Institute of Geography, Ruhr-University Bochum, Bochum, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Marschner
authors.affiliation: Department of Soil Science/Soil Ecology, Institute of Geography, Ruhr-University Bochum, Bochum, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Heinze
mesh_terms: D000383:Agriculture / Q000379:methods; D002104:Cadmium / Q000493:pharmacokinetics* / Q000633:toxicity; D018556:Crops, Agricultural; D005618:Fresh Water; D006801:Humans; D018551:Solanum lycopersicum / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D000455:Medicago sativa / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D019216:Metals, Heavy / Q000032:analysis; D018517:Plant Roots / Q000737:chemistry / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D054712:Salinity; D012987:Soil; D012989:Soil Pollutants / Q000032:analysis; D062065:Wastewater; D014867:Water; D014874:Water Pollutants, Chemical / Q000493:pharmacokinetics* / Q000633:toxicity; D014881:Water Supply; D015032:Zinc / Q000493:pharmacokinetics* / Q000633:toxicity
chemical_list: D002104:Cadmium; D019216:Metals, Heavy; D012987:Soil; D012989:Soil Pollutants; D062065:Wastewater; D014867:Water; D014874:Water Pollutants, Chemical; D015032:Zinc
keywords: Alfalfa; Cadmium; Salinity; Tomato; Wastewater; Zinc