PROBLEM TO BE SOLVED: To make soil in which disease is generated be a state that is appropriate for growth of a plant with promptness and safety.SOLUTION: A method for improving soil is characterized in that an aqueous solution including free hypochlorous acid is sparged to eliminate bacteria from soil, then the soil is applied with fertilizer including soil microorganism. A fungus in the soil and a majority of bacillus die by sparging the free hypochlorous acid with strong sterilizing properties to the soil, and growth of a survived part is controlled also. Afterwards, the soil is left for about 1 to 7 days for decomposition of the hypochlorous acid, and then is manured, microorganism having vigorous growth power included in a fertilizer grows and dominates, and growth of a disease bacterium is controlled further. A manure efficacy component included in the fertilizer contributes to create the environment that is appropriate for growth of a plant promptly.
