Abstract:
Licorice is not only an important Chinese herbal medicine, but also widely used as an additive in food industry. With the increasing demand of licorice, wild licorice resources can not meet the needs of the market. Artificial cultivation of licorice has become an effective way to solve the problem between the supply and demand of licorice resources. Direct seeding method leads to dredge difficult and large labor consumption when harvest because of its low seedling survival rate, large quantity, long growth cycle, and deep roots. Research shows that seedling transplanting can be used for licorice planting. By this way, the licorice roots can grow strongly and healthily with good quality and high yield; and it is also easy for mechanized harvesting. Seedling transplanting is an ideal cultivation model for artificial cultivation of licorice. At present, the cultivation of licorice in China is still in the manual operation stage, from which exist many problems, such as large labor input, high cost, low production efficiency, poor transplanting quality, etc. Due to the impact of the above problems, the scale of the cultivation of artificial transplanting of licorice has been greatly restricted. A lot of relevant research documents show that the development trend of the cultivation of licorice is the mechanization of transplanting. However, the research on the transplanting machine of licorice in China is still in its early stage, and there is no mature and practical application of the licorice root transplanting machine. In this paper a licorice tilt transplanting opener was proposed. The analysis and experiment of the structure and work parameters of the opener were carried out, which provided the research foundation for the design of the licorice transplanting machine. In order to analyze the forming mechanism of the tilt transplanting furrow opener, the soil backflow model and seedling position parameter model were built. Through analyzing results of the mathematical model, a multi-factors orthogonal test for the opener was executed by changing the soil backflow port angle, the space between two wing plates, velocity, the furrower operating depth and the soil repose angle. The opener orthogonal test results showed that main influencing factors of the inclined V type groove tilt angle was the soil backflow port angle. The primary and secondary order of the factors affecting the length of the ditch was: the furrow opener operating depth, the soil backflow port angle, the space between two wing plates, the soil repose angle and the velocity. The results also showed that the formula built by mathematical model could be used for design the opener to make V type inclined groove. Under the agronomic condition of 30° inclined transplanting with 300 mm long licorice roots. When the lag seedling coefficient value less than 1, the licorice angle decreased with the lag seedling coefficient value decreased, and decreased with the increase of the opener velocity. When the lag seedling coefficient value was equal or greater than 1, the licorice angle fluctuated between 28°-31°. The opener had the advantages of stable working performance.