The present invention relates to a manufacturing method of a soil improving material which comprises the following steps of: refining montmorillonite by pulverizing; manufacturing slurry by adding a solution in the refined montmorillonite; impregnating a vegetable carrier with the slurry by spraying the slurry. Accordingly, the present invention has an effect of newly cultivating by injecting the montmorillonite safely and uniformly in a farmland in which a repeated cultivation is not possible, and a land which is not sufficient for cultivating by spraying the refined montmorillonite to the vegetable carrier with the pressure. Additionally, the present invention may offer the soil improving material with low price by using a waste which is easy to be obtained such as food remnant, coffee sediment, dried rice straw, wheat straw, and a rice husk for the vegetable carrier.
