title: Modelling arsenic toxicity in wheat: simultaneous application of diffusive gradients in thin films to arsenic and phosphorus in soil.
abstract: The diffusive gradients in thin films (DGT) technique was evaluated in modelling wheat (Triticum aestivum) arsenic toxicity using a dataset of As-contaminated soil samples (n = 28) collected from former sheep dip sites. Above ground wheat biomass from a 21-day early growth bioassay was adopted as the response variable and the dose-response relationships were modelled using the three-parameter sigmoid equation. The DGT-derived effective soil solution As to P concentration ratios corresponded strongly to the differences in the response variable. With a single sample identified as an outlier, the 95% confidence interval for the effective soil solution As/P molar concentration ratio which resulted in a 50% reduction in the response (EC50) was 0.168-0.360. While the DGT-derived soil measure of As/P ratio was shown as a promising phytotoxicity predictor, the influence of P nutrition on the dose-response relationship deserves further consideration.
authors.affiliation: Department of Soil and Physical Sciences, Faculty of Agriculture and Life Sciences, PO Box 84, Lincoln University, Lincoln 7647, Christchurch, New Zealand. ognjen.mojsilovic@ecan.govt.nz
authors.forename: Ognjen
authors.initials: O
authors.lastname: Mojsilovic
authors.forename: Ron G
authors.initials: RG
authors.lastname: McLaren
authors.forename: Leo M
authors.initials: LM
authors.lastname: Condron
mesh_terms: D000822:Animal Husbandry; D001151:Arsenic / Q000032:analysis / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004784:Environmental Monitoring / Q000379:methods; D008954:Models, Biological; D010758:Phosphorus / Q000032:analysis / Q000633:toxicity*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis / Q000633:toxicity*; D014908:Triticum / Q000187:drug effects*
chemical_list: D012987:Soil; D012989:Soil Pollutants; D010758:Phosphorus; D001151:Arsenic