Research On Dry Land Automatic Transplanter For Plug Seedling

There are many unique advantages of transplanting seedlings technology for dry land crops, Such as acheving stable and high yields, raising the utilization of land, etc. However, the applieation of this technology mainly relies on manual operation at present in China. Manual transplanting of seedlings is labor-intensive, expensive, time consuming and often results in non-uniform plant distribution, witch prevent the development of transplanting technology. Semi-auotomatic transplanting machine was developed and used in some aeras of China since1980s. But it hasn’t been widely used because of the low effience and high labour intensity. The goal of this work was to develop a dry land automatic transplanter for tomoto plug seedlings with higher effency.Conclusions was as follows,1. Make the measurement and statistic alanalysis on morphological charaeteristics and distribution of tomato plug seedlings. Make the research of the relationship between moisture and pullout strength, and the relationship between moisture and breakage of rooting medium.Design three seedling picking up device and perform the seedling pick up experiment. According to the test result, insertion type seedling picking up device was chosen to be the object of the study.2. The The key components of automatic transplanter including seedlings picking up device, seedling feeding device and planting device were developed. The paper introduces a novel geared five-bar linkage seedling pick-up device. Structure parameters, trajectory and dynamic characteristics of the device are optimized with simulation. On the basis of theoretical studies, a seedling pick-up bench was designed.The feeding of seedlings consist of longitudinal and horizontal traverse. A pair of ratchet and pawl is used to achieve longitudinal feed, and the combination of intermittent involute gears and screw axis were used to achieve horizontal feed of seedlings. Dibble-type planting device was chosen to be the planting device. The paper gives the constraint formulas for zero-velocity planting and the least damage of mulch-film, which can provide theoretical support for the design of transplanting machine. The analysis and experiment showed that it’s better to plant seedlings during rising stage of the planting devices; Spacing can be changed by changing the transmission ratio or the number of planting devices.3. An trail-behind automatic transplanter was developed in this paper. It mainly consists of a geared five-bar seedling pick-up sevice, a seedling giving device, a planting device, soil covering device et al. It is driven by land wheel and pulled by a22kw tractor. Seedlings are provided in the right place at appropriate time by the seedling feeding device. Seedlings are picked one by one by the pick-up device. The picked seedling is carried and dropped in the dibble of planting device, and then planted in the field and covered with soil with the help of soil covering device. The performance of the transplanter was evaluated for transplanting tomato in the field.The efficiency of the transplanter was found to be71.7plugs·min-1, and the rate of seedlings missed to pick-up was2.9%and the rate of missed to plant is4.4%.