Peanut has been one of the most important cash crops in recent years. This study aims to explore the effects of the tillage depths and planting densities on the photosynthetic behavior and peanut yield p in coastal saline-alkaline land. A split-zone experiment was conducted in a representative saline-alkaline land of the Yellow River Delta. Two time periods were divided into: 2023 and 2024, from May to September. The peanut variety “Yuhua 18” was used as the material. The influencing factor of the fracture zone was used to assess the peanut growth under different treatments. The influencing factor split-zone was adopted as the first major type of treatment area. Three treatments were set as the tillage depths of 10, 15, and 20 cm, respectively, noted as D1, D2, and D3, respectively. At the same time, the subzones were also divided, according to the different densities. Three treatments were taken as the planting density of 178 000, 212 000, and 261 000 plants per hectare, respectively, noted as R1, R2, and R3, respectively. Such partitioning was designed to explore the interactions of different tillage depths and planting densities under the planting mode for the precision sowing of the single grains. Together, a systematic investigation was made to determine the photosynthetic behaviors of peanut leaves at the critical reproductive periods, such as the seedling, flowering, pod setting, and pod filling stages. In addition, the components of peanut yield were also evaluated at the harvesting stage. The results revealed that there were significant differences in the peanut growth and yield potential under different treatments. Specifically, the chlorophyll content and net photosynthetic rate of peanut leaves were performed at the highest level under the combination of 212 000 plants per hectare and 20 cm tillage depth, indicating the maximum at the podding stage. The chlorophyll and photosynthetic capacity also increased the overall growth potential of the plant. The number of pods per plant and the rate of full pods were higher by 9.52% and 4.58, respectively (averaged for two years), compared with the rest treatments. The leaf area index of peanut leaves reached the maximum at the podding stage under the combination of 261 000 plants per hectare planting density and 15 cm tillage depth. An optimal combination of planting density and tillage depth was achieved to improve the plant population quality. Correspondingly, the kernel rate and pod yield were at least higher by 5.34% and 2.45%, respectively (averaged for two years), compared with the rest treatments. Therefore, two planting schemes were used as the preferred coupling mode of the high-yielding peanut in the coastal saline-alkaline land. The most suitable environmental parameters were determined for peanut growth, such as the appropriate water, air, and heat. The yield of peanuts was eventually improved due to the high efficiency of photosynthesis. The finding can also provide the theoretical reference for the high-yield peanut cultivation in the coastal saline-alkaline land. It is of great significance to explore the saline-alkaline land resources. Meanwhile, more planting modes can be suitable for the cropping patterns of the peanut in the saline-alkaline land, thereby expanding the cultivation area of peanuts. Furthermore, a stable supply of food and oil products can gain national security in the soil resources of saline-alkaline land.

Combine harvesting machinery is commonly used in peanut production nowadays. However, there is no effective way to concurrently cut the roots and remove the residual mulch for peanut vines in the field. A double-disk root cutter can be expected to dig up the peanut plants and collect the peanut pods in the planting area. The one-ridge-two-row combine harvesting can be realized to effectively remove the residual mulch. In this study, a double-disk root cutter was designed to work with a double-row peanut combine harvester, in order to effectively remove the residual film. The kinematics, dynamics, and operation analysis were also performed on the key components of the double-disk root cutter. The structural and operational parameters were then determined for the double-disk root cutting and the film removal. The simplification of the model was first carried out using Solidworks software. Mesh delineation was then implemented using Hypermesh software. Explicit dynamics were finally simulated using Ansys LS-DYNA software. According to the physical and mechanical properties of the peanut vines, the cutting force, stress, and energy were determined under the working settings after simulation. The cutting performance was also compared on the three pairs of disk cutters: serrated/serrated, non-serrated/non-serrated, and serrated/non-serrated disk cutting knives. The optimal combination was determined as the serrated/non-serrated disk cutting knives (AB type). Furthermore, the one- and multi-factor experiment was conducted to optimize the test factors. The optimal combination of the operating and structural parameters was then achieved in the maximum force of the root cutting and cutting energy. The results show that the optimal performance of the double-disk root cutter was achieved in the root cutting and film removal, where the rotary speed and the tilt angle of the disk cutter were 239 r/min and 5°, respectively, as well as the feeding speed was 901 mm/s. The field test of the peanut combine harvester was also carried out to verify the simulation, according to the optimal combination of the parameters. A better performance was obtained, where the cutting rate of the peanut root disks was 96.9%, and the film removal rate of the peanut vines was 98.3%. The finding can also provide a theoretical reference to improve the performance of the mechanization equipment in the peanut industry.

Maize is one of the most extensively cultivated grain crops in China. The high-speed precision seeding is required under land intensification, particularly for the optimal timing, entropy-adapted sowing, and yield enhancement. Among them, the air-suction precision seeding can be combined with the constrained seed guide and zero-speed seeding. The disturbing seed filling and multi-stage seed cleaning have been reliable for the high-performance seeding. However, the constrained seed guiding has been confined to the uncontrollable trajectory of seed migration, especially under the strong collision between the seed and the constrained seed guiding device at the high speed. Eventually, there is a sharp increase in the coefficient of variation of the seed spacing, when the seed is thrown. The large initial speed of the seed can be found, when leaving the seed plate in the high-speed corn planter. The collision and bouncing with the inner wall of the seed guide tube can also lead to the decrease in the qualified rate of the seed spacing. In this study, a high-speed seed guiding device with brush belt was designed to transfer the seed into the control wheel that assisted seed-brush synchronous belt. The direction control wheel was utilized with the opening/closing finger shafts to form the seed cavities during guidance. Single grain was sequentially deposited on the brush tubes. The stable transportation and zero-speed delivery were realized after the brush-belt rotation. The performance factors and their operational ranges were identified after structural optimization and theoretical analysis. The dynamic model was constructed for the rotary steering to the control wheel, as well as the transfer and seeding of the brush belt. The influencing factors on the steering trajectory of the control wheel were obtained as the installation angle of the control wheel relative to the seeding plate. The length of the brush and the diameter of the belt wheel were the influencing factors on the stability of the seed holding and seeding of the brush belt. A single-factor test was carried out on the directional control wheel that assisted the seed acceptance using Adams-EDEM coupling platform. The seed was fully met the guidance requirements, when the installation angle of the directional control wheel relative to the seed plate was 15°. The stable guidance trajectory was also achieved after simulation. The secondary rotation orthogonal test was carried out with the brush length and the pulley diameter as the test factors, and the qualified spacing rate, the multiple seeding rate and the missed seeding rate as the test indexes. The test results show that the qualified spacing rate was 96.03%, the missed seeding rate was 1.76%, and the multiple seeding rate was 3.48%, when the operating speed was 13km/h, the brush length was 24.9 mm, and the pulley diameter was 53 mm. The performance of the seed guiding device was verified at different operating speeds, according to the optimal combination of parameters. Once the operating speed was 12-16 km/h, the qualified spacing rate was not less than 94.3%, the multiple seeding rate was not higher than 3.92%, the missed seeding rate was not higher than 3.19%, and the damage rate was not higher than 0.19%. This finding can provide a strong reference to optimize the high-speed seed guide device.