PROBLEM TO BE SOLVED: To provide a method and an apparatus for feeding a nutritious liquid, constituted so as to be able to operate by only one automatic controller, capable of storing wastewater in a liquid storage tank without discarding the wastewater from the bottom of a plant culturing bed and feeding the liquid to plants, capable of making a stock solution mixing device to act on a stock solution feeder, storing the wastewater from the bottom of the plant culturing bed in the liquid storage tank and feeding the liquid to the plant culturing bed, and provide a technique capable of mixing the feed liquids by a feed pump and feeding the mixed feed liquid to the plant culturing bed. SOLUTION: This method and apparatus for feeding a nutritious liquid comprise mixing plural stock solutions with water by feeding the stock solutions from plural stock solution feed devices to a stock solution mixing device to afford the nutritious liquid, enabling feed of the nutritious liquid suitable for plants, feeding the nutritious liquid to a plant culturing bed 5, storing excess wastewater from the plant culturing bed 5 in the storage tank, feeding the wastewater to the nutritious liquid feed device, feeding a insufficient fertilizer to the stock solution mixing device and passing the fertilizer through the mixing device and passing the nutritious liquid through nutritious liquid piping line of a nutritious liquid feed system and feeding the liquid to the plant culturing bed 5.
