Water-saving irrigation device and irrigation method for forestry seedling culture

The invention discloses a forestry seedling culture water-saving irrigation device and an irrigation method, and relates to the technical field of irrigation. The forestry seedling culture water-saving irrigation device comprises a water distribution pipe and an irrigation head arranged on the water distribution pipe, the irrigation head comprises a shell, a main pipe is arranged in the shell in the axial direction, water enters the lower end of the shell, the water in the shell can enter the main pipe, and a water wheel is fixedly arranged on the circumference of the lower end of the main pipe so that the main pipe can rotate when water enters the shell; the multiple jet pipes are arranged in the circumferential direction, close to the upper end, of the main pipe, the lower ends of the jet pipes are rotationally installed on the periphery of the main pipe, and connecting hoses are communicated between the jet pipes and the main pipe; the adjusting ring is arranged at the upper end of the shell, a slope throu