Effects Of Biochar On Accumulation And Tolerance Of Heavy Metal Cadmium In Apple

The heavy metal cadmium?Cd?pollution has become increasingly serious due to the industrial waste pollution and the extensive application of chemical fertilizers and pesticides in some areas in history.The soil pollution area of Apple orchard in China is also relatively extensive,and Cd plays an inhibitory role on the growth and development of plants.Biochar has the effect of reducing Cd toxicity.Using pot experiment method,this study exogenous add 0?M,500?M Cd Cl₂treatment cultivation soil,and the use of biochar in Cd contaminated soil?0,0.5%and 3.0%?,treatment after70 d,by measuring soil basic properties,photosynthesis and growth index,Cd content in each group,the resistance index,Cd of Cd cells content and chemical form distribution,antioxidant levels and other indicators,research on the cold rich apple biochar grafting effect of Cd accumulation and tolerance.The results showed that biochar increased chlorophyll B content,tissue biomass,root and stem tolerance.Biochar addition significantly increased the biomass of seedling roots,and the higher the added concentration was,the greater the increase was.The stomatal conductance and photosynthetic efficiency were significantly improved after biochar treatment of 3.0%.The addition of biochar effectively reduces the content of available Cd in soil,improves the resistance of plants and the activity of antioxidant enzymes in vivo,inhibits the absorption and enrichment of Cd by plants,and thus reduces the toxic effect of Cd on plants.The greater the amount of biochar added,the better the effect.When cultured for 70 days,the p H value of soil treated with 3.0%biochar increased by22.9%,the content of soil organic matter increased by 23.5%,and the available Cd content decreased by 0.32 mg kg^-1compared with the control group.After biochar application,oxidative stress in plant tissues was reduced.Application of biochar could effectively reduce the content of Cd in the tissues of cold rich apple seedling,and the effect of biochar treatment was the best,and the content of Cd in roots,stems and leaves was 34.06%,21.57%and 23.33%lower than the control.