Sugarcane/soybean intercropping with reduced nitrogen addition is an important sustainable agricultural pattern that can alter soil ecological functions, thereby affecting straw decomposition in the soil.  However, the mechanisms underlying changes in soil organic carbon (SOC) composition and microbial communities during straw decomposition under long-term intercropping with reduced nitrogen addition remain unclear.  In this study, we conducted an in-situ microplot incubation experiment with 13C-labeled soybean straw residue addition in a two-factor (cropping pattern: sugarcane monoculture (MS) and sugarcane/soybean intercropping (SB); nitrogen addition levels: reduced nitrogen addition (N1) and conventional nitrogen addition (N2)) long-term experimental field plot.  The results showed that the SBN1 treatment significantly increased the residual particulate organic carbon (POC) and residual microbial biomass carbon (MBC) contents during straw decomposition, and the straw carbon in soil was mainly conserved as POC.  Straw addition changed the structure and reduced the diversity of the soil microbial community, but microbial diversity gradually recovered with decomposition time.  During straw decomposition, the intercropping pattern significantly increased the relative abundances of Firmicutes and Ascomycota.  In addition, straw addition reduced microbial network complexity in the sugarcane/soybean intercropping pattern but increased it in the sugarcane monoculture pattern.  Nevertheless, microbial network complexity remained higher in the SBN1 treatment than in the MSN1 treatment.  In general, the SBN1 treatment significantly increased the diversity of microbial communities and the relative abundance of microorganisms associated with organic matter decomposition, and the changes in microbial communities were mainly driven by the residual labile SOC fractions.  These findings suggest that more straw carbon can be sequestered in the soil under sugarcane/soybean intercropping with reduced nitrogen addition to maintain microbial diversity and contribute to the development of sustainable agriculture.

The circulating avian influenza viruses in wild birds have a high possibility of spillover into domestic birds or mammals at the wild bird-domestic bird or bird-mammal interface. H8N4 viruses primarily circulate in migratory wild waterfowl and have rarely been identified in domestic birds. In this study, we summarized the spatial and temporal distribution of global H8 viruses, specified their natural reservoirs, and performed detailed evolutionary analysis on the dominant H8N4 viruses. Here, we also reported a novel H8N4 virus isolated from a Eurasian coot sample from a wetland in eastern China in 2022. Animal infection studies indicated that the wild bird-originated H8N4 virus can replicate and transmit efficiently in ducks but has not adapted to chickens. Additionally, this naturally isolated H8N4 virus can replicate in mice without prior adaptation. These results indicate that H8 viruses exist mainly in the wild duck reservoir and pose a high infection risk to domestic ducks. Therefore, the active surveillance of influenza viruses at the wild and domestic waterfowl interface will contribute to monitoring the circulation of these viruses.