Preliminary Study On Biochar-microbe Remediation Of High Manganese Soil

In recent years,due to a large number of mining resources,the mining process has caused serious damage and pollution to the surrounding environment.Especially the damage to the surrounding soil is more serious.Not only slows down the growth of plants,but also affects food security and other issues.The soil around a certain iron-manganese tailings pond has high manganese content,with a manganese content of 6954 mg/kg.In this study,manganese oxidizing bacteria screened from the soil around a certain iron-manganese tailing pond were used to prepare biochar from corn stover,and manganese oxidizing bacteria and biochar were used to prepare biochar-microbial inoculants.The effects of biochar-microbial inoculants on manganese-contaminated soil restoration,plant growth-promoting effects on plant rhizosphere soil microbial diversity were studied.The main research results are as follows:(1)Biochar-microbial inoculants improve soil p H and EC,increase soil organic matter content(OM)and soil fertility index AK,etc.,making the soil environment more conducive to plant growth.Compared with the blank control,the application of biochar,bacterial solution and biochar-microbial inoculants all increased the proportion of residue state.In the presence of biochar-microbial inoculants,the residue state increased by 21 %;microaggregates in the soil(≤0.25 mm)transformed into large aggregates(>0.25 mm);the activities of urease,invertase and catalase increased,the maximum value of invertase activity was 45.11 mg/d/g,and the maximum value of urease activity was 1711.75 U /g Soil samples.(2)The experimental results showed that the biochar-microbial inoculants increased the dry weight,fresh weight,number of leaves,chlorophyll content and soluble sugar content of pakchoi.The fresh weight and dry weight were increased by 62.1 % and 94.7 %,respectively,compared with the control;the number of leaves increased by 28.57 %;the chlorophyll a increased by 5.54 % compared with the control;the chlorophyll b increased by 32.83 %compared with the control.(3)Using high-throughput sequencing technology to measure the soil microbial community in the rhizosphere of pakchoi,mainly through the composition of the soil microbial community,principal component analysis and the correlation analysis of the soil microbial community to determine the biochar-microbial inoculants respectively The influence of pakchoi rhizosphere soil bacterial community and fungal community.The bacterial and fungal communities in the rhizosphere soil of pakchoi with biochar,manganese oxidizing bacteria,and biochar-microbial inoculants were different at the phylum level and the genus level.The use of biochar-microbial inoculants for remediation has an impact on the soil microbial community structure,and the abundance and diversity of bacteria are reduced.However,the application of biochar-microbial inoculants does not introduce some environmentally harmful bacteria,but activates The original microorganisms in the soil are changed,thereby changing the proportion of different microorganisms.From an ecological point of view,bioremediation did not cause a major change in the composition of the community.