PURPOSE: To obtain culture soil mixed with an effective microorganism promoting fermentation and humification of soil, having excellent cleaning effect on water, suitable for raising agricultural products, by blending rice bran with the effective microorganism composed of an aerobic bacterium, forming the blend into pellets and mixing the pellets with soil.

CONSTITUTION: This culture soil is obtained by mixing rice bran with an aerobic bacterium, preferably an effective microorganism composed of an aerobic bacterium and anaerobic bacterium, forming the mixture into pellets and blending the pellets with soil such as soil of a huge heap of coal waste. The amount of the pellets used is preferably 2-3%.