ANALYSIS OF SOIL STRESS VARIATIONS DURING THE SEEDLING PLANTING PROCESS WITH DIRECT INSERTION SEEDLING DEVICE

To explore the change law of contact stress distribution in the process of planting seedlings, the greenhouse transplanting equipment was developed to reduce labor intensity and improve the mechanization level of facility horticulture. This paper takes the direct insertion seedling planter as the research object, adopts the pressure distribution measurement system to study the soil stress distribution rule of different cross-section, digging depth and types of seedling planter. Both horizontal and longitudinal sections were obtained to show an increasing and then decreasing trend. The stress distribution is basically consistent at different digging depths, and the peak contact stress is roughly located at the center position. With the increasing of digging depths, the soil disturbance increases by the seedling planter and the hole tray seedlings, and the peak contact stress also shows a gradually increasing trend, leading to a gradual increase in the peak resistance of the seedling planter. The peak contact stress of the four opening seedling plant was higher than that of the three opening seedling plant. The main reason was that the soil disturbance of the four opening seedling plant increased, the peak contact stress distribution increased, and the peak resistance also increased. This study provides a basis for designing the greenhouse transplanters.