A fertilizing method for agricultural irrigation includes a step of passing aqueous solution of activation agents through a fertilizer fixed bed composed of nonaqueous granular phosphatic fertilizer and fertilizer or mineral containing medium or trace element to achieve irritation water for irritating plants. With the method of present invention, the consumption of fertilizer can less 30-60% than that of conventionally fertilizing method, and thus the utilization ratio of fertilizer is up to 70-90%.
