Rotary tillage, ridging, and mulching are commonly used cultivation methods for crops such as chili peppers, tomatoes, and strawberries in the arid regions of Northwest China. An integrated machine for rotary tillage, ridging, and mulching was designed by considering the growth characteristics of pepper root systems and the agronomic requirements of ridge beds. The structural parameters and their value ranges for key components such as the rotary tillage device and the ridging device were determined. By introducing the Bonding contact parameter, the soil cohesion between soil particles during the process of rotary tillage and ridging can be simulated. A coupled simulation model using the Discrete Element Method (DEM) and Multibody Dynamics (MBD) is established. The experimental factors selected were rotary tillage depth, ridging roller speed, and machine forward speed. The evaluation indexes were the traction resistance of the stemming roller and the soil compactness of the ridges. A response surface Box–Behnken Design test was carried out to obtain the best working parameters of the rotary tillage and ridging process for chili pepper cultivation as follows: the rotary tillage depth was 176 mm, the ridging roller speed was 283.71 r/min, and the machine forward speed was 0.55 m/s. Field experiments with optimal parameters showed that the ridge top width was 549.2 mm, the ridge bottom width was 750.5 mm, the ridge height was 222.9 mm, the ridge spacing was 1173.1 mm, the surface smoothness of the ridge was 12.3 mm, the width of soil covering the film edge was 76.3 mm, the stability coefficients of the ridge size parameters were all above 91.73%, and the soil compactness after operation was 60.82 KPa. All indicators meet the requirements for the rotary tillage and ridging cultivation of chili peppers in arid regions, providing reference for the design of rotary tillage and ridging mulching implements and the development of sustainable agriculture.

To address issues such as uneven flattening and high stem breakage rate in post-harvest alfalfa field conditioning operations, an adjustable-clearance flattening and modulating device was designed. The device incorporates a dual-spring floating pressure mechanism and preload adjustment mechanism to ensure the adaptive performance of conditioning rollers during alfalfa stem flattening. Based on the biological characteristics of alfalfa stems, a rigid–flexible coupling model between stems and the flattening and modulating device was established. Using the Discrete Element Method (DEM) and Multibody Dynamics (MBD) co-simulation technology, experiments were conducted with feeding amount, roller speed, and buffer spring preload force as test factors, while stem crushing rate and bonding key fracture rate served as evaluation indices. Box–Behnken experimental design was employed to simulate the dynamic conditioning process, followed by regression analysis of the simulation results. The findings revealed optimal parameter combinations as follows: feeding amount of 5.10 kg/s, modulation roller speed of 686.87 r/min, and buffer spring preload force of 670.02 N. According to the optimal combination of parameters to carry out field tests, the average flattening rate of stem and stem crushing rate were 95.71% and 1.73%, respectively, which showed small relative error with the predicted value and met the requirements of alfalfa steam flattening and modulation operation. These research findings provide theoretical basis and technical support for the design and optimization of alfalfa flattening and modulating devices.