Fertilizer adding device

The invention discloses a fertilizer adding device. The fertilizer adding device comprises a power assembly, a control unit, two splicing guide rail assemblies, a sliding base assembly and a fertilizer applying device. The two splicing guide rail assemblies are cooperatively used to achieve splicing of guide rails needed by advancing of the sliding base assembly. A splicing guide rail assembly comprises a base and a guide rail body. The base is positioned below the guide rail body, comprises a base body and a base force application assembly, and plays a role in supporting and positioning the guide rail body; the guide rail body is used for guiding the sliding of the sliding base assembly; the sliding base assembly is positioned on the guide rail body in a sliding manner, and the body is plate-shaped and is used for bearing the fertilizer applying device; the fertilizer applying device is positioned on the sliding base assembly and is used for realizing the functions of digging holes, adding fertilizers and fi