**5. Conclusions**

In this study, a discrete meta-simulation model of rotary tillage knife-soil-straw interaction was developed. The interaction law of soil-touching components in deep tillage operation was explored, and the field experiment results also verified its usability. The optimized structural parameters of the rotary tillage blade were 210 mm-45 mm-37◦-115◦ (R-H-α-β). The simulated and field comparison tests were conducted under the optimal combination of parameters, and the power, soil breaking rate, and straw burial rate were 1.73 kW, 71.34%, and 18.89%, respectively; the numerical error rates of simulated and field test values were 6.36%, 5.42%, and 8.89%, respectively. The accuracy of the secondary model was verified.

Note that the aim of the study was to investigate the interaction of the rotary single blade with the soil straw in deep rototilling operations, applicable to optimizing the structural parameters of the rotary blade, and our experiments found that the soil movement was more consistent with the simulation results, which confirmed the validity of the simulation model. Papers exploring the arrangement of the rototill knives and the operating parameters have been published in the literature and will be the focus of our future work. Deep rototill mulching of straw will also be a hot research issue in the tillage chain.

**Author Contributions:** Conceptualization, J.Z. (Jin Zhang) and C.W.; methodology, J.Z. (Jiping Zhu); software, J.Z. (Jin Zhang); validation, W.C., M.X. and D.Y.; formal analysis, J.Z. (Jin Zhang); investigation, M.X.; resources, W.C.; data curation, J.Z. (Jin Zhang); writing—original draft preparation, J.Z. (Jin Zhang); writing—review and editing, J.Z. (Jiping Zhu); visualization, J.Z. (Jiping Zhu); supervision, W.C.; project administration, M.X.; funding acquisition, J.Z. (Jiping Zhu). All authors have read and agreed to the published version of the manuscript.

**Funding:** The author thanks Jiping Zhu of Nanjing Institute of Agricultural Mechanization, Ministry of Agriculture and Rural Affairs for funding this work through the National Key Research and Development Program of China (2020YFD1000802), Jin Zhang of Jiangsu Yanjiang Institute of Agricultural Sciences for Science Fund for Young Scholars of Jiangsu Yanjiang Institute of Agricultural Sciences (YJ2022006), Liu Jian of Jiangsu Yanjiang Institute of Agricultural Sciences Jiangsu Province Science and Technology Project (BE2020388), Jiangsu Province Modern Agricultural Machinery Equipment and Technology Demonstration and Extension Project (NJ2020-04).

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

**Data Availability Statement:** The data presented in this study are available within the article.

**Acknowledgments:** Thanks are due to Zhenggang Liu for assistance with the experiments and to Yurong Zhang for valuable discussion.

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