# Current Status and Future Directions for Combined Tillage and Sowing Technology and Equipment
## 2 Status of Development of Combined Tillage and Sowing Machines  
### Combined Rotary Tillage and Sowing Machine  
Combined rotary tillage and sowing machines integrate various rotary tillers and planners designed for soil preparation and sowing. These machines position the rotary tiller at the front and the planter at the rear, streamlining the soil preparation and sowing processes. The working principle of combined rotary tillage and sowing machines is that the front rotary tiller completes the process of plowing, burying, and crushing the soil, achieving the complete mixing of soil and straw, finely crushing soil particles, and providing an excellent and flat seedbed for subsequent trenching and sowing, which is conducive to improving the soil water supply capacity and root system development. The planter sows the seeds into the seed furrow to complete the planting process. The machine is primarily connected to the tractor through a suspension device. It is suitable for various applications, has an excellent operating effect, improves efficiency, enhances quality, and reduces energy consumption [19; 20; 21]. The combined tillage and sowing machines are divided into vertical rotary tillage and sowing combination machines and horizontal rotary tillage and sowing combination machines according to different forms of rotary tillage. Vertical rotary tillage and sowing combination machines consist of vertical shaft tillage implements and various types of planners. The rotary plowing parts rotate around the vertical axis and carry out shallow rotary operations on the ground surface, which loosens the soil and preserves moisture, and eliminates grass. It has a firm soil crushing ability, and its plowing depth is generally 150\(\sim\)360 mm, which has less influence on the disturbance of soil structure and is suitable for use with large and medium-sized planners [22; 23]. Numerous enterprises for vertical rotary tillage have implemented furrow sowing mode in-depth research to enable the stable performance of mature technology vertical rotary tillage and sowing combination machines, while the overall progress around the development of mechanical intelligence and quantitative data has improved the quality of sowing. LEMKEN has designed the Saphir 7 combined mechanical precision planter for wheat, oilseed rape, and bean crops. The machine adopts the form of vertical rotary tillage and mechanical strip sowing, which can complete the seedbed pre-sowing preparation and precision sowing operation with vertical rotary tillage knives under the condition of ensuring the sowing depth and stabilizing the sowing amount. The s-drill plus seed drills launched by Kverneland are compact in design, which can reduce power consumption during operation. The central measuring device equipped with the equipment can monitor the number of seeds in real time. In addition, its CX-II plow ensures smooth operation and the precise placement of seeds. The compaction wheel of the implement can be set in a fixed or floating position and then can quickly adapt to different soil working conditions through mechanical or hydraulic plow tooth pressure, achieving uniform depth control [24; 25]. The vertical rotary tiller is a powerful tool for breaking stubble, loosening soil, retaining moisture, and controlling weeds. It helps optimize the seedbed, leading to high operating efficiency and sowing quality. This combination machine effectively addresses various issues in farming and promotes agricultural production. However, due to its generally large installations, it requires higher power support, has high processing and usage costs, and is suitable for use with medium and large-scale planners on larger farms, which can lead to higher soil compaction and power consumption during operation. Horizontal rotary tillage and sowing combination machines are mainly small and medium-sized planners due to the structural characteristics of the tillage parts.