Effects of long-term rice-crayfish rotation on soil bacterial community structure
We investigated the impacts of long-term rice-crayfish rotation on physicochemical properties and bacteri-al community structure in paddy soils.Chemical analysis methods and high-throughput sequencing of 16S rRNA amplicons were employed to examine the soil physicochemical properties and bacteria community structures in rice monoculture and rice-crayfish rotation systems with durations of 4,8,and 21 years.Results showed that rice-cray-fish rotation significantly increased total phosphorus content by 37.01%-54.33%(P<0.05),but decreased availa-ble phosphorus content by 60.21%-61.10%(P<0.05)compared to rice monoculture.Results of principal coordi-nate analysis and multivariate analysis of variance showed significant differences in soil bacteria community structure across systems with different rotation years(P=0.004).Long-term rice-crayfish rotation increased the relative abundance of Aminicenantia(family,order,class,genus)and Sva0485(family,order,class,genus)in paddy soil.Redundancy analysis(RDA)results identified organic matter and available nitrogen as key factors influencing bacterial community structure.Overall,rice-crayfish rotation affected soil phosphorus levels and altered the abun-dance of bacterial phyla,without impacting community diversity in soil bacteria.Our results provide valuable insights into the impact of rice-crayfish rotation on paddy soil bacterial communities.