▎ 摘　　要

NOVELTY - Preparing biological bacterial fertilizer comprises (i) (a) mixing activated mixed microbial inoculum containing Bacillus subtilis and a nutrient solution to obtain a base liquid, mixing base liquid with graphite powder to prepare graphite suspension, (b) grinding suspension to obtain base liquid, and (c) allowing degradation of e.g. fragment proteins in fertilizer liquid, (ii) (a) placing prepared graphite dispersion liquid in a special device, adopting new technique of synchronously preparing graphene and micro-nano biological bacteria fertilizer, performing high shear grinding and adopting same technique in same liquid medium, and performing liquid phase stripping, (b) allowing newly produced graphene to immediately react with released amino, hydroxy and carboxy groups in micro-nano biological fertilizer liquid fertilizer, dispersing graphene nano-material in base liquid, forming stable graphene dispersion liquid, preparing nano graphene synergistic agent and mixing. USE - The method is useful for preparing biological bacterial fertilizer. ADVANTAGE - The method utilizes low-cost graphite powder to directly prepare low-cost graphene and micro-nano biological bacterial fertilizer that works synergistically with graphene in the biological bacteria fertilizer liquid. DETAILED DESCRIPTION - Preparing biological bacterial fertilizer comprises (i) (a) mixing the activated mixed microbial inoculum containing Bacillus subtilis, and a nutrient solution including fragment-containing protein, amino acid compound, polypeptide and humic acid total content of 30-50% by adopting mixed fermentation technology to obtain a biological bacteria fertilizer liquid as base liquid, mixing the base liquid with graphite powder based on the weight parts of 1000:5-30 to prepare a graphite suspension, (b) cyclically grinding the graphite suspension in a high-speed colloid mill with the rotating speed of 15000-30000 revolutions/minute for 30-80 minutes to obtain the base liquid of graphite dispersion liquid of the biological bacteria fertilizer, and (c) allowing the degradation of the fragment proteins, amino acid compound, peptides and humic acid in the biological bacteria fertilizer liquid to produce free amino acid, oligopeptide and fulvic acid because of the mechanical force of the high-speed colloid mill while preparing the graphite dispersion liquid, (ii) (a) placing the prepared graphite dispersion liquid in a special device for synchronous preparation of graphene and micro-nano biological bacteria fertilizer, adopting the new technique of synchronously preparing graphene and micro-nano biological bacteria fertilizer directly in the base liquid of the graphite dispersion liquid of biological bacteria fertilizer liquid, performing high shear grinding at the rotating speed of 3000-6000 revolutions/minute and for 3-8 hours by high shear mechanical force, adopting the same technique in the same liquid medium, and simultaneously performing liquid phase stripping to prepare graphene and liquid-phase ultra-micro crushing to prepare micro-nano biological bacteria fertilizer liquid, (b) allowing the newly produced graphene to immediately react with the newly released amino, hydroxy and carboxy groups in the micro-nano biological fertilizer liquid fertilizer to form hydrophilic active groups at the moment of stripping and producing graphene under the action of high shearing mechanical force, dispersing the graphene nano-material in the micro-nano biological bacteria fertilizer base liquid, forming stable graphene dispersion liquid, preparing nano graphene synergistic agent, mixing graphene synergistic micro-nano biological bacteria fertilizer with the micro-nano biological bacteria fertilizer; where the base liquid of biological bacteria fertilizer liquid comprises Bacillus subtilis group and actinomycete group, nitrogen fixing bacteria group, nitric acid bacteria group, phosphate solubilizing bacteria group, potassium solubilizing bacteria, photosynthetic bacteria group, mixed microbial flora of lactic acid bacteria group, and fragment protein, amino acid compound, polypeptide, humic acid and multiple element and trace element required by the plant, and the total content of the amino acid compound, polypeptide, fragment protein and humic acid organic nutrient substance in the biological bacteria fertilizer liquid is 30-50%, the effective viable count of biological bacteria fertilizer liquid is greater than or equal to 2 billion/ml, the organic nutrient substance in the biological bacteria fertilizer liquid is rich in amino, hydroxy and carboxy and graphene release agent and modifying agent, the graphite is natural crystalline flake graphite, expanded graphite, expandable graphite, oxidized graphite, graphite powder and/or amorphous carbon; and the biological bacteria fertilizer comprises micro-nano biological bacteria fertilizer and graphene nano-material in a ratio of 1000:5-30 based on the weight parts, the total number of required organic and inorganic nutrients with a grain diameter in the range of 100-600 nm is not less than 50%, and the proportion of graphene particles with a diameter of less than 200 nm is more than 10%.