There are many excitation sources and complex vibration environments in combine harvesters. The coupling and superposition of different vibration signals on the plate and shell seriously affect the working parts of the body. This also reduces the reliability of the whole machine. At present, domestic and foreign research on existing harvesters mainly focuses on harvesting performance, with less research on vibration characteristics. Therefore, in this paper, the vibration response of the metal plate–shell under the two connection modes of bolt connection and welding is studied, in order to optimize the design and structure of the plate–shell structure of the combine harvester and improve the overall performance. First, the welded and bolted plates are numerically modeled using Hypermesh pre-processing functions. Then, the boundary conditions are simulated by continuous variable stiffness elastic constraint experiments. Finally, the intrinsic vibration dynamic model of the four-sided simply supported plate and four-sided solidly supported plate is established using the modal superposition method. By analyzing the modal frequencies and vibration patterns, the following results are obtained. The connection method between the plate and the frame has a significant impact on the inherent vibration characteristics of the plate. The bolt connection will make the plate’s intrinsic vibration frequency higher than that of the welding method, but the effect on the plate’s intrinsic vibration pattern is more minor. At the same time, in order to verify the accuracy of the model, the actual modal vibration patterns and frequencies of the same proportion of plates in the modal test are compared with the results of modal vibration patterns and frequencies obtained by Ansys. The errors of the two dynamic model analytical methods are within 1% and 3%, respectively. This result verifies the accuracy of the dynamic model of the metal plate and shell structure under different connection methods.

As rice yield rises, the issue of broken axis windings in mature rice threshing drums is becoming increasingly severe. To disclose the winding characteristics and signal traits of the drums during the threshing process of mature rice, this paper undertakes an analysis of the winding characteristics and signals of the drums in rice with the assistance of a vibration test and analysis system. Since rice can lead to drum winding and shaft breakage, this paper alters the driving mode of the drums to exhibit the influence of rice on them. Firstly, the transfer characteristics of the frame need to be studied and analyzed, followed by subsequent research. The test results indicate that the horizontal displacement of the cylinder axial trajectory rises with the growth of the transmission chain, while the vertical displacement drops with the growth of the transmission chain. Additionally, to investigate the effect of mature rice on the threshing performance of horizontal axis II and horizontal axis III, a control variable method was employed. This approach allowed for the observation of how mature rice influences the threshing roller by systematically adjusting both the threshing gap and the rotational speed of the roller. It can be discerned from the test results that with the reduction of the threshing gap of affected mature rice, the unstripped rate gradually declines, while the entrainment loss rate gradually increases. As the rotational speed of horizontal shaft roller III increases, the rate of uncleared material gradually decreases, while the rate of entrainment loss progressively rises. The research findings can furnish a reference for the winding characteristics of rice on rollers and the enhancement of vehicle driving comfort.

Crop rotation is a key practice for improving soil health, reducing chemical inputs, and ensuring sustainable agricultural productivity. This review synthesizes research from major agricultural regions worldwide, including North America, Europe, South America, South Asia, and Africa, with additional case studies from China to illustrate regional applications. This study presents a streamlined framework that integrates climate adaptability, crop combinations, yield-enhancing mechanisms, technological support, and regional optimization. By analyzing plant–soil–microbe interactions—including improvements in soil physical structure, nutrient cycling, microbial processes, and suppression of pests and diseases—we elucidate how rotation systems enhance the yield of subsequent crops. Precision agriculture technologies, such as variable-rate fertilization and remote sensing, have been shown to improve resource use efficiency and reduce labor input in certain cropping systems. Diversified crop rotations can substantially offset direct greenhouse gas emissions through enhanced soil carbon sequestration. The design of region-specific recommended rotation patterns should follow the principles of resource matching, stable yield and efficiency enhancement, and sustainability. This framework provides a practical reference for designing region-specific rotation systems and advancing sustainable agricultural development.