# Current Status and Future Directions for Combined Tillage and Sowing Technology and Equipment
## 2 Status of Development of Combined Tillage and Sowing Machines
### Combined Disk Harrow and Sowing Machine  
Different operational forms of combined tillage and sowing machines are developed to meet diverse agronomic requirements. A combined disk narrow and sowing machine is an operation machine that adopts a disk narrow group combined with different planners to realize the functions of breaking stubble, loosening soil, leveling, seeding, and fertilizer application [29]. The typical combined disk narrow and sowing machine is usually large and of high quality, with a complex structure that requires a large tractor or other powerful machinery for operation. It is typically connected to the power machinery through traction or semi-suspension. The machine operates at a high speed and efficiency, making it suitable for large-scale agricultural production and meeting the needs of large farms [30; 31]. The Primera DMC seeder, manufactured by Amazone, offers versatile functionality, accommodating no-tillage and conventional sowing modes. Its applicability spans multiple crops, including wheat, corn, and sugar beets. The machine is designed with a chisel-shaped furrow opener and ring-shaped depth-limiting wheels on both sides of the plow blade to ensure a precise sowing depth and cleanliness. Additionally, the machine features an AMALOG+ terminal for path planning and hectare counting, enabling precise and intelligent operation [32]. Kverneland has developed the u-drill plus large-scale combined strip-till machine. The machine mainly consists of a disk narrow and a pneumatic seeder, which can perform pressing, moisture consolidation, sowing, fertilizer application, and pressing. The front of the machine is equipped with a front wheel sealer for leveling the soil and crushing the clods. It is assembled with two rows of narrow sets arranged in a conical shape, which can effectively enhance the effect of tillage. The Headland Management System is equipped with a metering device to monitor and control the disks and plow blades to achieve a uniform depth of tillage and sowing and a uniform seeding volume [33]. Researchers have developed small and medium-sized combined disk narrow and sowing machines to meet the demands of various agricultural environments. AMAZONE has launched the Centaya Super narrow-mounted seed drill. This machine has a compact structure and low power consumption, making it suitable for small and medium-sized plots. The SmartCenter operator station and Highly precise metering system equipped on the equipment ensure the quality of sowing [34]. AGRODAHUA has introduced the 2 BMYFBQ Air seeders tailored for no-tillage and conventional sowing for corn, soybeans, and sugar beets. The machine features a two-row air-absorbent precision planter, enabling staggered precision sowing with fixed small-row spacing and achieving an efficient operating speed of 4-8 km/h. The equipment is suitable for small and medium-sized plots because of its compact structure, the fact that it is lightweight, and its low power consumption [35]. The typical machines are listed in Table 2.  
The combined disk narrow and sowing machine utilize different types of disk narrows to carry out tasks such as loosening, crushing, and clearing stubble. Compared with the combined rotary tillage and sowing machine, the power requirement is high, and it can carry out medium and high-speed operation. The machine has an advanced interactive control system to enhance operational precision. This system facilitates functions such as stabilizing plowing depth, precise sowing, and auxiliary operations, thereby elevating the machine's intelligence. As a result, it effectively minimizes soil disturbance and damage, leading to energy conservation and reduced consumption while ensuring high efficiency and high-quality operations. The machine is prone to congestion blockage and shallow seed burial in environments with straw stubble cover and sticky soil.