| 摘要 |
PROBLEM TO BE SOLVED: To easily distribute liquid fertilizer and liquid pesticide to the underground of a farm field by using an existing water supply pipeline.SOLUTION: A subirrigation system 10 includes a water supply pipeline 12, for example, constituted by hole pipes, embedded in the ground of a farm field. A submersible pump 58 is set in a solution 56 in a water tank 54. The solution is fed from a discharge port of the submersible pump through a solution feeding pipe 60 into a trunk pipeline 14. The solution thus fed flows from the upstream side to the downstream side of the trunk pipeline by a pressure of the pump. On the course, the solution permeates from the pipe wall holes of the trunk pipeline to the underground of the farm field. The residual solution in the trunk pipeline is circulated from the downstream side to the upstream side of a branch pipeline 18 by the pressure of the submersible pump. On the course, the solution permeates from the pipe wall holes of the branch pipeline to the underground of the farm field. The residual solution in the branch pipeline is fed back into the water tank through a return pipe 62. |
