Studies on Effects of Soil Properties on Cd Accumulation in Tobacco and Prediction Model

The accumulation of cadmium(Cd) in tobacco(Nicotiana tabacum L.) as affected and predicted by soil properties was investigated using 15 soils with a wide of properties and pot experiments. Results indicated that the main soil factors affecting the accumulation of Cd in tobacco were in the following order: soil Cd concentration, pH and organic matter content. The accumulation of Cd in tobacco plants in acidic soils was greater than that in alkaline soils. Also, it was found that exogenous water soluble Cd added to soils was more easily absorbed by tobacco compared with Cd in soils. The quantitative relationship between concentration of Cd in tobacco plants and soil properties was log [Plant Cd] = 3.041 + 1.212Log [Soil Cd]-0.270pH- 0.264log [Organic carbon], which could be used to predict well the concentration Cd in tobacco plants based on soil Cd, pH and organic carbon content. Meanwhile, the results showed that the concentration of Cd in tobacco plants could be significantly reduced by increasing soil pH and decreasing concentration of soil Cd.