An irrigation system supplies a nutrient solution containing nutrients required for a nutrient bed where the nutriculture of a plant is performed, and recovers a drained nutrient solution to reuse the same. The present invention relates to a nutrient solution-circulating irrigation control system which partially reuses the recovered drained nutrient solution after a sterilization process, and partially and consistently reuse the recovered drained nutrient solution. Accordingly, the generation of pathogens is inhibited and a loss in nutrients included in the drained nutrient solution can be minimized. Furthermore, the nutrient solution-circulating irrigation control system efficiently controls supply, sterilization processes, etc. of a nutrient solution and a drained nutrient solution, and thus can create an optimal environment for the growth of a plant. The nutrient solution-circulating irrigation control system comprises: a nutrient solution unit comprising a nutrient solution tank and a nutrient solution pump； a drained nutrient solution unit supplying a drained nutrient solution to a nutrient bed and a sterilization unit； the sterilization unit sterilizing the drained nutrient solution and supplying the same to the nutrient bed； and a control unit controlling operations of the nutrient solution unit, the drained nutrient solution unit, and the sterilization unit.본 발명은 식물이 양액 재배되는 양액베드에 필요한 영양분을 함유한 양액을 공급하고 배액을 회수하여 재사용하는 관수시스템에 있어서, 회수된 배액 중 일부는 살균 처리한 후 재사용하고 일부는 그대로 재사용하도록 구성하여 병원균의 발생을 억제하고 배액에 포함된 영양분의 손실을 최소화할 수 있으며, 양액과 배액의 공급, 살균처리 과정 등을 효율적으로 제어하여 식물의 생장에 최적화된 환경을 제공할 수 있는 양액순환식 관수제어시스템에 관한 것이다.
