title: Influence of nutrient amendments on the phytoextraction of weathered 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene by cucurbits.
abstract: Field experiments were conducted to determine the impact of nutrient amendments on the phytoextraction of weathered 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene (p,p '-DDE) by eight cultivars of cucurbits over a single growing season. Four cultivars of Cucurbita pepo ssp pepo are accumulators and extract percent level quantities of persistent organic pollutants (POPs), whereas C. pepo ssp ovifera and Cucumis sativus are nonaccumulators. The nonamended accumulators phytoextracted 1.0% of the p,p'-DDE and had a translocation factor of 0.44; however, the nonaccumulators removed 0.16% of the contaminant and had a translocation factor value of 0.09. The accumulators also had 3.8 times greater inorganic element content than the nonaccumulators. Duplicate mounds of each cultivar also received weekly nutrient amendments of phosphorus (400 mg/L K2HPO4), nitrogen (200 mg/L KNO3), or nitrogen/phosphorus (400 mg/L K2HPO4, 200 mg/L KNO3); a minus phosphorus treatment involved a 1-L addition of 1 g/L AlSO4 to the soil before planting. When normalized to respective control values (unamended vegetation), the root and stem p,p'-DDE bioconcentration factors (BCF) of the accumulator cultivars were significantly greater than those of the nonaccumulator cultivars under most nutrient regimes. The biomass of accumulator cultivars decreased by up to 61% under certain nutrient regimes, resulting in mixed effects on the amount of p,p'-DDE extracted. Treatment with N and P increased nonaccumulator biomass by 40 to 100%, and increased p,p'-DDE extraction from soil by 75%. Although generally assumed that fertilizer amendments will enhance phytoremediation, as evidenced here by the nonaccumulators, additions of macronutrients may reduce the phytoextraction of weathered POPs by C. pepo ssp pepo. These findings support our hypothesis that the ability of C. pepo ssp pepo to remove sequestered organic contaminants is governed by unique nutrient-acquisition mechanisms.
authors.affiliation: Department of Soil and Water, Connecticut Agricultural Experiment Station, New Haven, Connecticut 06504, USA. jason.white@po.state.ct.us
authors.forename: Jason C
authors.initials: JC
authors.lastname: White
authors.forename: Zakia D
authors.initials: ZD
authors.lastname: Parrish
authors.forename: Mehmet
authors.initials: M
authors.lastname: Isleyen
authors.forename: Martin P N
authors.initials: MP
authors.lastname: Gent
authors.forename: William
authors.initials: W
authors.lastname: Iannucci-Berger
authors.forename: Brian D
authors.initials: BD
authors.lastname: Eitzer
authors.forename: Maryjane Incorvia
authors.initials: MI
authors.lastname: Mattina
mesh_terms: D000534:Alum Compounds / Q000494:pharmacology; D018533:Biomass; D018553:Cucumis sativus / Q000737:chemistry / Q000187:drug effects / Q000254:growth & development; D028464:Cucurbita / Q000737:chemistry / Q000187:drug effects* / Q000254:growth & development; D003633:Dichlorodiphenyl Dichloroethylene / Q000032:analysis* / Q000378:metabolism; D005308:Fertilizers; D007287:Inorganic Chemicals / Q000032:analysis; D009584:Nitrogen / Q000032:analysis / Q000494:pharmacology*; D009930:Organic Chemicals / Q000032:analysis; D010758:Phosphorus / Q000032:analysis / Q000494:pharmacology*; D018517:Plant Roots / Q000737:chemistry / Q000187:drug effects; D018547:Plant Stems / Q000737:chemistry / Q000187:drug effects; D012621:Seasons; D012987:Soil / Q000032:analysis; D014018:Tissue Distribution
chemical_list: D000534:Alum Compounds; D005308:Fertilizers; D007287:Inorganic Chemicals; D009930:Organic Chemicals; D012987:Soil; D010758:Phosphorus; C041524:aluminum sulfate; D003633:Dichlorodiphenyl Dichloroethylene; D009584:Nitrogen