Globally, the imperative to improve nitrogen retention and enhance N use efficiency in saline-alkali soil is critical for sustainable agriculture and food security. To address the issues of high N loss and low N use efficiency in saline-alkali soil, this study used soil column cultivation experiments and the ZmNRT1.1B loss-of-function mutation of maize to investigate the impacts of vermicompost and Azotobacter chroococcum on N loss (NH 3 volatilization and 15N leaching), available 15N and maize N uptake in a saline-alkali soil. The results showed that the addition of vermicompost and A. chroococcum decreased NH 3 volatilization through decreased Na + and pH, and increased of cation exchange capacity. These additions were also found to decrease the 15N leaching though increased soil organic carbon and macroaggregates, thereby increasing soil available 15N. In addition, they were found to promote growth and N uptake of wild-type maize, most likely through increased soil available N and decreased Na +/K + in the roots. In particular, the increased available 15N was absorbed through ZmNRT1.1B gene activity, as evidenced by maize with ZmNRT1.1B loss-of-function unable to perceive NO 3 - signals, which did not promote growth and N uptake. These suggested that findings will contribute to improving the management and sustainable use of N resources in saline-alkali soil.