Department of Soil and Physical Sciences, Faculty of Agriculture and Life Sciences, PO Box 84, Lincoln University, Lincoln 7647, Christchurch, New Zealand.
Environ Pollut. 2011 Oct;159(10):2996-3002. doi: 10.1016/j.envpol.2011.04.022. Epub 2011 May 14.
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.
薄膜扩散梯度（DGT）技术在使用从前羊群浸泡场采集的受砷污染土壤样本数据集（n = 28）来模拟小麦（Triticum aestivum）砷毒性方面进行了评估。采用 21 天早期生长生物测定的地上小麦生物量作为响应变量，并使用三参数 S 形方程对剂量-反应关系进行建模。DGT 衍生的有效土壤溶液 As 与 P 浓度比与响应变量的差异密切相关。在一个样本被确定为异常值的情况下，导致响应（EC50）降低 50%的有效土壤溶液 As/P 摩尔浓度比的 95%置信区间为 0.168-0.360。虽然 DGT 衍生的土壤砷/磷比被证明是一种有前途的植物毒性预测指标，但磷营养对剂量-反应关系的影响值得进一步考虑。
