Drip irrigation has been one of the most efficient water-saving irrigation modes in arid and semi-arid regions, due to its water use efficiency and crop yields. Subsurface shallow burial installation can directly deliver water and fertilizers to crop root zones, thereby minimizing water evaporation loss from the surface soil dry and effectively suppressing the growth of pests, diseases, and weeds. Typically, trenching, belt laying, and soil covering are included in the subsurface shallow burial installation of drip tape. Among them, the trenching and shallow burial stage can dominate the burial depth accuracy and installation quality of the drip tape. However, it is often required for manual fixation at the free end of the drip tape during initial installation, particularly for the unstable trenching depth. Belt slack can also occur during emergency braking. In this study, a drip tape trenching and shallow burial device was designed with self-braking mechanism, including a contour-following trenching and shallow burial mechanism, a drip tape guidance mechanism, a drip tape clamping mechanism, a drip tape roller, a braking mechanism, and a tape press-down mechanism. Functions were integrated in the device, such as stable trenching, belt pressing, and self-braking. Specifically, contour-following trenching and shallow burial mechanism was used to precise control of the drip tape burial depth using a sliding blade-type furrow opener and a parallelogram profiling structure, i.e., a sliding blade-type furrow opener with a 45° sliding-cutting angle and a 45° blade edge angle, along with a parallelogram profiling mechanism in a profiling range of 93.78 mm. Tape press-down mechanism was used to effectively restrain the displacement of the free end of the drip tape using an elastic compaction wheel. Tension spring parameters were designed after optimization, according to the required tension range of 242.94-488.70 N. In braking mechanism, the coordination between a brake rod and a brake wheel was utilized to prevent slack in the drip tape during emergency braking. The tension range of the brake tension spring was calculated as 44.89-67.35 N using the drip tape's tensile force. A soil bin test was conducted to verify the performance of the device. The results showed that the average burial depth of the drip tape ranged from 37.4 to 48.1 mm at different operating velocities, with a burial depth stability exceeding 94%, fully meeting the agronomic standards. The displacement of the drip tape in the tape press-down mechanism was less than 1 000 mm at various velocities, particularly without manual fixation. The well-designed tension spring parameters enabled the friction rubber pad to engage rapidly with the brake wheel during emergency braking, thereby effectively suppressing inertial slack. A tension spring force of 55 N or higher achieved high braking performance at an operating velocity of 6 km/h. The post-braking slack of the drip irrigation belt was significantly reduced from 8 674.6 mm (without the braking mechanism) to 32.4 mm at the tension spring force of 60 N, indicating a reduction of over 99%. This findings can provide theoretical and technical support to promote the shallow burial installation of drip tapes during irrigation in sustainable agriculture.

To solve the problem of small planting plots and large sloping land for mechanized maize harvesting in China hilly and mountainous areas, a small maize harvester with attitude adjustment was designed to realize maize snapping, peeling, straw crushing and attitude adjusting at on time in this study. The basic structure and working principle of the small maize harvester were described, and the key components were designed as follows. The maize snapping device adopted the combination form of maize snapping plates and straw pulling rollers, and the gap of the straw pulling rollers can be adjusted to adapt to different maize varieties. Two pairs of peeling rollers formed a groove arrangement to improve peeling rate and reduced ear grain loss. The pressure feeding device mainly comprised drive chain and three grade pressure feeding rollers to increase the friction between ears and the peeling rollers, and help ears slide. The attitude adjustment advice was designed according to the high point stationary pursuit leveling method. When the attitude angle of the rack approached 0, the small maize harvester reached the level state. The actual range of attitude adjustment was obtained and the accuracy of static attitude adjustment was verified through attitude adjustment test. The influencing factors of ear loss rate and bract peeling rate were determined by orthogonal test, including the rotational speed of straw pulling rollers, peeling rollers and pressure feeding rollers. The mathematical regression model between the experimental factors and indicators was established by using Design Expert, and through the analysis variance to verify the significance of the evaluation indicators, the best combination of operation parameters was determined that the rotational speed of straw pulling rollers, peeling rollers and pressure feeding rollers were 1440 r/min, 1535 r/min and 406 r/min. Under the optimal combination of the operation parameters, the ear loss rate and bract peeling rate were 1.33% and 93.98%. The design indicators of the small maize harvester can meet the relevant national standards, and can satisfy the need of maize mechanized harvesting in China hilly and mountainous areas.