The present invention relates to an irrigation control method for optimizing the root environment, and, more specifically, to an irrigation control method for optimizing the root environment capable of optimizing a rearing environment of crops by controlling the start and stop of irrigation with complex application of various environmental factors. The irrigation control method for optimizing the root environment comprises a critical value setting step of setting a minimum or maximum critical value to each environmental factor for optimizing the root environment of crops； and an irrigation control step of controlling to supply a nutrient solution with a preset concentration to the culture medium or to stop the supply thereof upon the critical values of the environmental factors. The irrigation control step comprises a first measurement step of measuring an accumulated solar radiation quantity, and measuring the culture medium concentration upon the nutrient solution included in the culture medium and the culture medium humidity upon the humidity included in the culture medium； and a nutrient solution supply step of supplying the nutrient solution to the culture medium once any one among the measured values of the accumulated solar radiation quantity, the culture medium concentration and the culture medium humidity reaches the critical value, wherein the nutrient solution supply step is characterized in that the nutrient solution is supplied when either the measured accumulated solar radiation quantity or the measured culture medium concentration is more than the maximum critical value, or the measured culture medium humidity is less than the minimum critical value. [Reference numerals] (AA) Start；(BB) End；(S10) Set maximum, highest critical value for various environmental factors；(S12) Start supplying culture medium；(S14) Stop supplying culture medium본 발명은 근권환경 최적화를 위한 관수 제어 방법에 관한 것으로, 좀 더 구체적으로 다양한 환경요인을 복합적으로 적용해 관수의 시작과 중단을 제어하여 작물의 생육 환경을 최적화할 수 있는 근권환경 최적화를 위한
