不同微生物肥对植烟区镉污染土壤的修复效果

为研究不同微生物肥对土壤中Cd的钝化效果和烟叶Cd含量的影响，选取南方植烟区3种不同类型(红泥田、黄泥田及青紫泥田)Cd污染土壤，以南方主栽烤烟云-87和K-326为测试品种，采用盆栽试验，测定了3种微生物肥(DY、AMS和HMD)在不同浓度下对烟草生物量、不同部位烟叶Cd含量、土壤Cd形态以及土壤中微生物种类的影响。结果表明：(1)3种微生物肥均能增加烟叶生物量，其中HMD增重效果最好。(2)与对照相比，3种微生物肥能有效地降低土壤中Cd的有效性和烟叶Cd的含量。针对3种土壤施用微生物肥浓度为1.5%时，叶片中Cd的降Cd率(与对照相比)分别达到17.2%~63.9%、20.4%~58.3%及18.9%~48.3%，DTPA-Cd下降比例分别为13.8%~17.3%、17.2%~22.8%及12.8%~16.2%；而随着施用微生物肥浓度增加到3.0%后，上述土壤烟叶中Cd的降Cd率显著增加，分别为20.3%~59%、31.3%~66.6%及25.2%~56.1%，DTPA-Cd下降比例分别为15.5%~28.2%、19.6%~26.6%及13.8%~17.3%。HMD效果最好，其次为DY和AMS。(3)3种微生物肥都增加土壤中微生物种类和数量，优化了烟草生长环境。总体来说，该植烟区土壤，DY和HMD增加产量的同时降Cd效果较好，可以在大田推广使用。

Effect of biofertilizers on the remediation of Cd-polluted soils in tobacco cultivating area

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.