Research On Absorption,Accumulation And Reduction Of Heavy Metal Pb In Tobacco

Heavy metal pollution seriously threatens the safety of tobacco products,its repair measures are divided into two aspects of heavy metals from the source control and improve.With tobacco cv.Yuyan12 as material,the activity of roots system,Soil microbial,pb content in tobacco leaves and changes of leaf biomass with the application of biochar and different fertilizers under Pb stress were explored by pot experiment.It was showd that :(1)Lead concentration in soil is one of the important factors affect tobacco uptake of heavy metal lead,each part of the root,stem and leaf of tobacco plant effective as the soil increases with increasing of the concentration of lead,lead each place specific accumulation pattern is: root > stem > leaf;Each part of the tobacco leaf accumulation of heavy metal lead also each are not identical,test showed that the lower leaf > middle leaf > upper leaf.Soil lead concentration of 1000 mg/kg,roots,stems and leaves of tobacco plant lead accumulation and largest rises rapidly.Experiment of tobacco to lead enrichment coefficient is 0.48 2.75,enrichment coefficient is negatively related with soil lead stress concentration,lead concentrations higher than 200 mg/Kg,enrichment coefficient is less than 1,show that tobacco hyperaccumulation plants not lead,heavy metal lead is mainly accumulated in the underground part after the absorption of tobacco plant root system.Compared to under low concentrations of lead stress of smoke Zhu Zhu higher high,high levels of lead stress,the agronomic traits of tobacco plant index declined,the different parts of tobacco plant biomass decreased significantly,inhibit the growth of tobacco.tobacco(2)Tobacco leaf biomass increased by 190.8% after inorganic + organic fertilizer treatment compared to the control.Tobacco leaf biomass then increased by 6.9% after addition of biochar,leading to an increase of 9.6% in the available Pb content in soil,and a decrease of 25.78% in the available Pb content in tobacco leaves.(3)The bacteria and fungi in soil microorganisms first increased and then decreased in quantity under different fertilizer application methods,the population of actinomycetes first decreased and then increased on the whole,and the microorganism quantity significantly increased after biochar treatment,suggesting that biochar effectively reduced the concentration of heavy metals in soil.Therefore,biochar could be used as a fertilizer source to significantly lower the content of heavy metal Pb in soil and tobacco leaves,increase tobacco leaf biomass,and improve the microbial activity in soil.