土壤中的重金属有可能被作物根部吸附,然后在作物中积累,当农作物被人类摄入时,最终会造成巨大的健康风险。因此,了解作物中重金属的富集模式具有一定的参考价值。薄膜中的扩散梯度(DGT)技术,作为一种原位被动采样方法,可用于评价土壤中重金属的生物可利用性。在这项研究中,通过DGT确定的土壤中生物可利用镉(Cd)的数据以及水稻和玉米籽粒中Cd的吸收,中国的浙江和广西是从WebofScience上以前的参考文献中收集的。通过比较生物富集因子,发现水稻和玉米中积累的重金属浓度遵循根>茎或叶>谷物的一般顺序。基于生物富集因子(BCF)和DGT法测定的生物可利用Cd含量,建立了玉米和水稻籽粒中Cd含量的准确、稳健预测模型,R2为0.986,均方根误差(RMSE)为0.128。这一结果表明,DGT方法可以预测作物对重金属的吸收。
It is possible for heavy metals in soils to be adsorbed by crop roots and then accumulated in crops, which eventually causes great health risk when the crops are ingested by humans. Thus, it is valuable to understand the enrichment model of heavy metals in crops. Diffusive gradients in thin-films (DGT) technique, as an in-situ passive sampling method, can be used to evaluate the bioavailable heavy metals contents in soils. In this study, data of the bioavailable cadmium (Cd) in soils determined by DGT and Cd contents uptake in rice and maize grains in Tianjin, Zhejiang and Guangxi provinces of China were collected from previous references in Web of Science. By comparing bioconcentration factors, it was found that the heavy metal concentrations accumulated in rice and maize followed a general order roots > stems or leaves > grains. An accurate and robust model for the prediction of Cd content in maize and rice grains was established based on bioconcentration factor (BCF) and the bioavailable Cd content determined by DGT method, with R2 0.986 and root mean square error (RMSE) 0.128. This result suggests that the DGT method can be good tool for predicting heavy metals uptake in crops.