Preparation method of additive for keeping fertility of culture soil

The invention relates to the field of microorganisms and microorganism fermentation, in particular to a preparation method of an additive for keeping the fertility of culture soil. The method disclosed by the invention specifically comprises the following steps: weighing 8 to 15 parts by weight of flora E-coliA01, 10 to 20 parts by weight of sawdust, 40 to 55 parts by weight of dried sewage sludge and 5 to 10 parts by weight of crushed fallen leaves; adding 15 to 60 parts by weight of water and mixing to a wet state carrying out heat preservation and moisture preservation for 4 to 8 days at the temperature of 25 to 35 DEG C to obtain the additive for keeping the fertility of the culture soil. The additive prepared by the preparation method mainly uses natural raw materials in the nature, is nonhazardous, has no pollution and can improve the growth environment of plants and improve efficiency of a fertilizer after growth of plants in one season is finished, by adding a small quantity of substances left by the