Preparation of soil auxiliary material comprises: providing charcoal with a average particle size of = 25 mm； contacting the charcoal with water and plant nutrients to obtain a growth medium； contacting the growth medium with soil micro organisms to obtain a culture medium； and incubating the culture medium at 25-37[deg]C for at least three days. Independent claims are included for: (1) A soil auxiliary material comprising charcoal, water, plant nutrients and soil micro organisms； and (2) A soil product comprising the soil auxiliary material and soil or another plant substrates, where the soil and the plant substrate are in the ratio of 1:99-20:80 wt.%. ACTIVITY : Fertilizer. MECHANISM OF ACTION : None given.
