The mechanized harvesting level of potatoes in the arid areas of Northwest China is low and mainly relies on simple machinery to dig the soil surface, and then people manually pick up and bag the potatoes. This harvesting method has the problems of a high labor intensity, low operation efficiency, and high labor cost. Based on this, a wheeled-chassis potato combine harvester with integrated bagging and ton bag-lifting systems was developed, which could complete potato digging, potato–soil separation, potato–film separation, automatic bagging, and field ton bag lifting in one go. Firstly, based on the agronomic requirements and unique terrain characteristics of potato planting in this area, the structural design of the whole machine was completed with SOLIDORKS 2019 3D software. Secondly, the dynamic model was established for a numerical analysis, and the core parameters of key components were determined. The field experiments showed that the potato loss rate was 2.1%, the potato damage rate was 1.7%, the skin breaking rate was 2.5%, the impurity content was 1.9%, and the productivity was 0.15~0.23 hm²/h. The above field test indexes met the requirements of national and industrial standards.

Flax, an important oil and fiber crop, is widely cultivated in temperate and sub-frigid regions worldwide. China is one of the major producers of flax, with Gansu Province predominantly practicing cultivation in hilly areas. However, common issues such as feeding difficulties, stem entanglement, and low threshing efficiency significantly restrict the improvement of planting efficiency. This study addresses the key technical challenges in flax combine harvesting in hilly regions by developing a discrete element model of the flax plant and utilizing DEM-FEA co-simulation technology. The performance of two threshing drum models (T₁ and T₂) was analyzed, focusing on motion trajectory, stress distribution, and threshing effects. The simulation results show that the T₂ model, with its combination of rib and rod tooth design, significantly improves threshing and separation efficiency. The loss rate was reduced from 5.6% in the T₁ model to 1.78% in the T₂ model, while the maximum stress and deformation were significantly lower, indicating higher structural stability and durability. Field validation results revealed that the T₁ model had a total loss rate of 3.32%, an impurity rate of 3.57%, and an efficiency of 0.09 hm²/h. In contrast, the T₂ model achieved a total loss rate of 2.29%, an impurity rate of 3.39%, and an efficiency of 0.22 hm²/h, representing a 144.4% improvement in working efficiency. These findings indicate that the T₂ model has a higher potential for flax harvesting in hilly and mountainous regions, especially in improving threshing efficiency and operational stability, providing an important theoretical basis for optimizing threshing equipment design.

Plastic film mulching is one of the key technologies for improving agricultural productivity in arid and semi-arid regions. However, residual plastic film can severely disrupt the structure of the topsoil in farmland, leading to a decrease in crop yield. The Hexi Corridor, as the largest seed maize production base in the arid regions of Northwest China, is facing an increasingly prominent issue of residual plastic film recovery. This study designed experiments based on the typical maize planting model in the Hexi Corridor. A discrete element simulation model of the residual film–soil–root stubble complex was established using the Bonding-V2 model and API rapid filling technology. The reliability of the simulation model was verified through shear and puncture tests. The study revealed that the soil type in the Hexi Corridor is heavy sandy soil. The differences between the average maximum shear forces in the simulated and actual shear tests for root stubble–soil complexes at depths of 30 mm, 50 mm, and 100 mm were 4.8%, 6.4%, and 6.5%, respectively. Additionally, the differences in the average maximum vertical loading forces in the simulated and actual puncture tests for root stubble–soil complexes at depths of 50 mm and 100 mm were 6.4% and 12.37%, respectively. The small discrepancies between the simulated and actual values, along with the consistency of particle movement trends with real-world conditions, confirmed the reliability and accuracy of the simulation model. This indicates that the established discrete element flexible model can effectively represent actual field conditions, providing discrete element model parameters and theoretical support for optimizing the design of key components in China’s mechanized root stubble handling and residual film recovery machinery.

To address the negative impacts in recovering large areas of residual plastic film from corn stubble in the Hexi irrigation area—such as the residual film containing substantial amounts of soil, corn stubble, and corn straw, and high power consumption during the operation process—in this study, a combined operation machine was designed for corn straw crushing and residual film recovery. The machine consisted of a double-wing, single-blade shovel for lifting the film and cutting corn stubble, a corn straw-crushing and returning device for reducing the residual film impurity rate, an eccentric teeth shifting cylinder for picking up residual film, a device for shifting residual film, and a collection device for bundling residual film. The key components of the combined operation machine were designed based on an agronomic model for corn planting and the mechanized operation requirements in the Hexi irrigation area. The optimal combination of operating parameters was devised based on theoretical calculations and single- and multifactor simulation tests. The results showed that when the angle of entry of the film-lifting shovel was 25.14°, the rotational speed of the eccentric teeth shifting cylinder was 80.96 rpm, and the forward velocity of the machine was 4.03 km/h, while the rate of recovery of residual film was 92.56%. The field test showed that the residual film contained 16.65% impurities, and the qualified rate of corn straw crushing was 88.51%, with a relative error of 0.65% from the optimized value. The experimental results provide theoretical support and a design reference for research on the mechanized recycling of residual film in large areas of corn stubble.

Minor cereals are an important part of the Chinese grain industry, accounting for about 8 percent of the country’s total grain-growing area. Minor cereals include millet, buckwheat, Panicum miliaceum, and other similar grains. Influenced by topographical and climatic factors, the distribution of minor cereals in China is mainly concentrated in the plateau and hilly areas north of the Yangtze River. In addition, there are large concentrations of minor cereals in Inner Mongolia, Heilongjiang, and other areas with flatter terrain. However, the level of mechanized harvesting in these areas is still low, and there is little research on the whole process of mechanized harvesting of minor cereals. This paper aims to discuss the current status of the minor cereal industry and its mechanization level, with particular attention to the challenges encountered in research related to the mechanized harvesting of minor cereals, including limited availability of suitable machinery, high losses, and low efficiency. The article provides a comprehensive overview of the key technologies that must be advanced to achieve mechanized harvesting throughout the process, such as header design, threshing, cleaning, and intelligent modular systems. It also summarizes current research progress on advanced equipment for mechanized harvesting of minor cereals. In addition, the article puts forward suggestions to promote the development of mechanized harvesting of minor cereals, focusing on aspects such as crop variety optimization, equipment modularization, and intelligentization technology, aiming to provide a reference for the further development and research of mechanized harvesting technology for minor cereals in China.

China is a large flax-growing country, with planting area and production ranking among the top three in the world. However, the cultivation range of flax in China is very broad, complex, and diverse, resulting in different planting scales and patterns, making it difficult to apply foreign large combine harvesters, and China lacks a dedicated flax combine harvester. This research improved the design of the 4LZ-4.0 crawler-type flax combine harvester for the regional features and flax cropping patterns in China. First, the structure, technical parameters, and working principles of the machine were introduced; second, the theoretical analysis and optimization of key components were performed; and finally, with the advancing speed of the machine, the speed of the threshing drum, and the speed of the suction fan as independent variables and the rate of removal and the total loss rate as response values, a three-factor, three-level response surface analysis method was used. For each component and response value, a mathematical model was created, and the factors and their interactions were evaluated and confirmed. The results demonstrated that the three parameters impact the threshing drum speed, advancing speed, and centrifugal fan speed in that order of priority, as well as the total loss rate in that order of priority. The machine’s optimal operating settings were 1.5 m·s⁻¹ advancing speed, 788.49 r·min⁻¹ threshing drum speed, and 885.34 r·min⁻¹ centrifugal fan speed, and the validation test results indicated that under the typical dryland dense flax cultivation mode, it had a 97.46% threshing rate and 2.99% total loss rate after the test. This demonstrated that optimizing operational parameters may decrease losses in the process of mechanical flax harvesting, enhance harvesting efficiency, and satisfy the marketable flax harvesting standards.