Abstract:
In response to the challenges of high labor intensity in rice cultivation, coupled with the difficulties and low efficiency associated with existing mechanical seedling throwing and nursery raising techniques, this study proposes a self-sequencing rice transplanter based on dynamic uniform seedling regulation. This innovation integrates several core technological modules: micro-feed seedling pushing, flexible oblique cutting for seedling combing, tandem uniform seedling distribution, and wind-assisted seedling delivery. Supported by a fully coordinated multi-module control system, the machine enables high-efficiency mechanized rice planting with improved precision and operational flexibility. The mobility system utilizes a tracked chassis with a ground pressure of 20.8 kPa, ensuring stable performance across varied field conditions, including wet and uneven terrain. The execution mechanism comprises three adaptive units: a flexible seedling-combing device, a two-stage uniform seedling distributor, and a high-speed seedling-blowing unit. Each component is designed to adjust its operational parameters dynamically in response to real-time field conditions and seedling characteristics, enhancing both adaptability and output consistency. During operation, seedlings are continuously drawn from the storage bin by the combing device and transferred onto a conveyor system. The two-stage dynamic uniform seedling mechanism then redistributes them evenly before the blowing unit accelerates the seedlings into the air, extending their trajectory to ensure proper penetration and spacing in the soil. An integrated intelligent control system continuously monitors seedling supply levels and planting effectiveness, providing actionable feedback for operational adjustments and process optimization. The overall dimensions of the self-sequencing rice transplanter are 3.5 m × 2.4 m × 2.5 m (length × width × height), and the total weight is
2400 kg. In April 2025, field trials were conducted in the Quyuan Management District, Miluo City, Hunan Province. A three-replicate comparative experiment was carried out using mechanical throwing and mechanical transplanting to validate the prototype's performance. The results show that the machine offers wide seedling adaptability, capable of effectively handling seedlings with a height of 8~20 cm and a substrate moisture content of 15%~25%. Compared with other mechanical transplanting methods, the overall operational efficiency of the machine has increased from 0.6 hm
2/h to 1 hm
2/h, and the number of workers required for manual assistance has been reduced from 3 to 1. The seedling raising process is simplified, and the planted seedlings exhibit a shortened recovery period, rapid regreening, early and abundant tillering, and a high panicle formation rate, effectively alleviating the cropping schedule tension in double-season rice systems. The machine achieves an operational efficiency of 1 hectare per hour, equivalent to the daily workload of a skilled farm laborer, significantly reducing production costs and improving economic returns. With a single load capacity covering 0.33 to 0.53 hectares of seedlings, the machine demonstrates stable and reliable performance in both field traversal and seedling throwing operations. The working width is adjustable from 4 to 7 meters, the seedling throwing distance is adjustable from 4 to 8 meters, and the travel speed ranges from 0 to 2 m/s, allowing flexible adaptation to planting density requirements for early, middle, and late-season rice varieties. Equipped with a human-machine interactive control system, the machine enables one-touch start-stop and automatic adjustment of operational parameters, allowing a single operator to complete all tasks. The full growth period for machine-thrown rice is 110 days, compared to 115 days for machine-transplanted rice, representing a reduction of 5 days. The average yield for machine transplanting is
7926.67 kg per hectare, while the average yield for machine throwing reaches
8519.10 kg per hectare, an increase of 6.95%. The technology demonstrates strong promotion potential, as it remains compatible with traditional seedling raising and throwing methods and shows good adaptability in southern rice-growing regions, effectively addressing labor shortages. Future work will focus on in-depth optimization of key components to further enhance operational performance and reliability. The maturation and widespread adoption of this technology are expected to bring revolutionary progress to mechanized rice cultivation.