5. Conclusions
N application could alter the effects of tillage practices on soil microbial diversity, community composition, biomass, and CUE. Bacterial and fungal diversities were more responsible for soil microbial CUEC:N than their biomass. Although microbial CUEC:N was more susceptible to tillage management than N application, it increased with an increasing in N application rate under the two tillage practices. Furthermore, soil microbial CUEC:N increased soil POC and MAOC contents and N application also increased the two SOC fractions. This research underscores the importance of N application to reveal the effect of tillage management on POC and MAOC from the perspective of soil microbial properties, which contributes to understanding the potential C sequestration benefits of N application under no-tillage.