Abstract: The purpose of this study is to explore the influence of different biofertilizers on  the remediation of Cd-polluted soil and Cd uptake by tobacco cultivars. Three kinds of Cd-polluted clay soilsred, yellow and blue purple clay from tobacco planting areas, along with two kinds of tobacco plant, Y-87 and K-326, used as testing cultivars, were selected for this study. A pot experiment was carried out to evaluate the effects of different biofertilizers(DY, AMS and HMD) on the biomass of tobacco plant, Cd distribution in tobacco plants, and Cd bioavailability and microbial diversity in soils. The results indicated that (1) Biomass of tobacco leaves increased significantly by applying three kinds of biofertilizers, with HMD being the most effective one. (2) Biofertilizer can significantly reduce soil and tobacco plant Cd contents compared to controls. Specifically, for the above three kinds of soils with the three biofertilizers used at 1.5% (mass fraction), tobacco leaf Cd(%) was reduced by 17.2%63.9%, 20.4%58.3% and 18.9%48.3%, respectively, and soil DTPA-Cd contents were decreased by 13.8%17.3%, 17.2%22.8% and 12.8%16.2%, respectively. At 3.0% (mass fraction), reduction of tobacco leaf Cd reached 20.3%59%, 31.3%66.6% and 25.2%56.1%, respectively, and soil DTPA-Cd contents were decreased by 15.5%28.2%, 19.6%26.6% and 13.8%17.3%, respectively. Among the different biofertilizers, HMD was the most effective, followed by DY and AMS. (3) Application of biofertilizers not only increased soil microbial diversity and population but also optimized the soil environment for tobacco growth. In general, DY and HMD can be used in the field since they have better effect on increasing tobacco yield while simultaneously reducing Cd uptake and translocation in tobacco plants.

Key words:  biofertilizer, tobacco cultivars, Cd, polluted soil, remediation