# The Analysis of the Applications of Crop Seed Tape Sowing Technology and Equipment: A Review
## 3 Research on Key Technology and Equipment for Seed Tape Manufacture
### Key Technology of Seed Tape Manufacture
#### 3.2.2 The Seed Metering Technology in Seed Tape Manufacture  
Theoretically, any seed metering device could be used for seed tape production. However, the common method of seed tape arrangement is mainly pneumatic seeding type or external force feed. The seed tape producing machine design by [PERSON] and [PERSON] used the external force feed. Although the hill spacing requirement can be theoretically guaranteed through the automatic control system, the collision between seed and seed tape could easily lead to inaccurate positioning. Therefore, some kind of seed tape wrapping machines will also include a gluing system.  
To improve the positioning accuracy of seeds in the seed tape, researchers have conducted detailed studies on both pneumatic seed metering devices and external force feed. [PERSON] [74] designed a rotary pneumatic seed rope winding machine, which has faster speed and efficiency, and a better seed positioning effect than previous generations of seed rope winding machines. The metering device designed by [PERSON] et al. [75] could extract the single seed from a specific tray and pinpoint them using an accumulator. In order to improve the accuracy and stability of the pneumatic seed metering device, a cylindrical stirring device was designed which realized accurate seeding of 1-3 seeds/hill [76]. [PERSON] [77] optimized the shape of the seed guiding tube and designed a supporter on the rice seed tape twisting machine. As a result, the two core devices greatly improve the performance of the seed tape twisting machine. Crop seed metering device usually uses multiple rice seeds for sowing, which is difficult to form a hill. If the seeds in the seed tape were wrapped in an irregular position, it would affect the emergence effect of seed tape [78].  
The rice seed metering device usually uses multiple rice seeds for sowing, which is difficult to form a hill, especially sowing on the seed tap. To improve the performance of rice seeding in one hill, [PERSON] et al. [79] based on the study of the trajectory of seed throwing optimized sucking holes on the sucking plate of the rice pneumatic seed metering device with an adjustable seeding rate. It was 10-17% higher than the original qualification rates of seed throwing, which greatly improved the qualification rate of seed throwing. [PERSON] [80] used a stepper motor controlled by a PLC to drive seed metering devices, which can accurately control plant spacing and improve seed quality. A kind of spiral lifting seed arrangement device designed by [PERSON] [81] was used in the seed rope winding machine. In the seedbox, a vertical spiral conveyor was used to transport the seeds from the bottom to the top. The top end of the spiral conveyor was connected with the outlet of the seedbox, and the seeds reach the outlet vertical chamber and then fall free on the tape to complete the seeding operation. Besides, some companies are providing various kinds of rope reels, such as SEDOS in Slovak. The seeds are placed on the seed tape by an air suction seed metering device (Figure 5).