Effects Of Eisenia Fetida On The Soils’ Chemical,Biological Properties And Bacterial Community Structures

Eisenia fetida were inoculated in the lateritic red soil,the orchard soil,the paddy soil and the vegetable garden soil from South China which were mixed with mushroom residue respectively in 10 days under the lab condition.The changes of the chemical and biological properties in the soils were evaluated.Moreover,the lateritic red soil and the paddy soil were selected,whose bacterial community structure compositions and diversities in undigested and digested soils were analyzed by 16 S rDNA Illumina Miseq high-throughput sequencing techniques.We studied the relationship between the soils’ chemical properties and the microbial properties affected by the earthworm and explored that how the earthworm affect the soils’ bacterial community structure by changing the chemical properties of the soils,which will provide an important theoretical support for the improvement of the soil quality by earthworms.The main results were as follow:(1)The lateritic red soil’s and the orchard soil’s chemical properties had the similar variation trend: their organic matter,total nitrogen,dissolved organic carbon and mineralized nitrogen were enhanced significantly(P<0.05),while their C/N ratio and available phosphorus were decreased significantly(P<0.05).The most chemical indices of the paddy soil had changed significantly: its organic matter,total nitrogen and mineralized nitrogen were enhanced significantly(P<0.05),while its p H,C/N ratio,dissolved organic matter and available phosphorus were decreased significantly(P<0.05).Unlike the other soils,the most indices of the vegetable garden soil had little change,such as its p H,organic matter,total nitrogen,C/N ratio and total phosphorus(P>0.05).(2)The lateritic red soil’s and the orchard soil’s biological properties had the similar variation trend: their biomass C and biomass C/N ratio were enhanced significantly(P<0.05),their biomass N was decreased significantly(P<0.05).The most biological indices of the paddy soil had changed significantly: its invertase,urase,acid phosphatase,biomass C and biomass C/N ratio were enhanced significantly(P<0.05),while its biomass N was decreased significantly(P<0.05).The vegetable garden soil’s enzymatic activities had a significant change,its invertase,urase and acid phosphatase were enhanced signicantly(P<0.05).(3)The bacterial community strctures of the laterictic red soil and the paddy soil had been changed: E.fetida decreased the relative abundance of Acidobacteria significantly by 44.90% and increased Bacteroidetes significantly by 14.88% in the lateritic red soil(P<0.05),while it decreased the relative abundance of Acidobacteria,Chloroflexi,Gemmatimonadetes,Nitrospirae,Planctomycetes,Verrucomicrobia significantly by 49.05%,20.44%,64.01%,35.00%,33.56%,24.38% respectively and increased Bacteroidetes and Spirochaetes significantly by 28.85% and 154.17% in the paddy soil(P<0.05).However,Proteobacteria,Actinobacteria,Acidobacteria et al were still the dominant bacteria.O verall,in the lateritic red soil it was increased at the presence of the earthworm while decreased in the paddy soil,the bacterial diversities in the two different types of soils both decreased.In summary,Eisenia fetida had different effects on the chemical,biological properties and bacterial community structures of different soils because of their different properties.We should use appropriate earthworms to improve the qualities of different soils in the practical productive application.