Development of a mechanism for transplanting rice seedlings

Transplanting of seedlings is a labor intensive operation in the cultivation of rice. It is also a skilled job and involves working with a stooping posture in a puddled field. There exists a need to mechanize this operation. For this purpose the design of a mechanism was carried out following the method of analytical synthesis. A planar four-bar linkage with coupler extension was selected as the basic design. The path generated by the mechanism was plotted on a computer screen. By varying the dimensions of various links in the mechanism different paths of output motion of the coupler point were obtained. The potential link dimensions were identified based on the suitability of the path for picking, conveying and planting of seedlings as well as the return motion. A four-row self-propelled transplanter using the above mechanism and an optimized-planting finger was then developed and tested. The machine transplanting system was found to be technically viable.