**5. Conclusions**

In this paper, an evaluation scheme for internal complex airway pressure loss was formulated, the influence of airway structure on pressure loss under different parameter combinations was explored, the internal flow field distribution and airflow movement law of a precision seeding device were defined, the drag reduction and efficiency increase were analyzed, and a new method was provided for the research of the pneumatic characteristics of complex narrow airway groups. The specific conclusions are as follows:


deviation of the seed-sucking hole was 0.54. The position of the seed-sucking hole has no significant influence on its airflow velocity.


**Author Contributions:** Conceptualization, X.Z., Q.W., H.L. and J.L.; software, Z.Z. and J.L.; validation, Z.Z., Z.W. and J.L.; investigation, Q.W., H.L. and X.Z.; resources, Q.W., H.L. and X.Z.; visualization, Z.W. and J.L. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the National Natural Science Foundation of China (Grant No.52175260), the China Agriculture Research System (CARS-03), the Key Research and development plan of Hainan Province (Grant No. ZDYF2022XDNY184), Project of Scientific Research in Colleges and Universities of Hainan Province (Grant No. Hnky2022-93) and Research Start-up Fund Project of Hainan University (Grant No. KYQD(ZR)-22036). The authors are grateful for their generous financial assistance.

**Institutional Review Board Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Conflicts of Interest:** The authors declare that there is no conflict of interest.
