NOVELTY - A biological organic fertilizer comprises (mass%): lignite (5-10), vinegar residue (50-65), sawdust or straw (20-25), shale (8-10), magnesium sulfate (1-2), zinc sulfate (0.5-1), borax (0.5-1) and microbial strains (0.1-0.2).    USE - Biological organic fertilizer for preventing protected field soil from salinizing (claimed).    ADVANTAGE - The contained organic material and humus can be adsorbed in soil to present free-state cations, thus decreasing concentration of soil solution and lightening salinization harm. The vegetable growth (recovery) period is prolonged by 10 days. The yield is increased by 8.5-22.6%. The incidence of diseases is dropped by 30.3-56.3% and nitrate content is reduced by 20.5-27.8%.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of the fertilizer which comprises (A) selecting microorganisms, (B) activating, (C) performing first stage, second stage and third stage amplifications, (D) blending, (E) performing fermentation, (F) pile turning, (G) obtaining finished product, (H) low-temperature drying, (I) detecting, (J) measuring and packaging, and (K) providing dosage and use method. The step (A) includes respectively selecting Clostridium themocellum (ACCC 00026) which is a freeze-dried strain and a market product; selecting Bacillus licheniformis which is a freeze-dried strain and market product (ACCC 11080); selecting Lactobacillus acidophilus (CGMCC 1.2686); and selecting Streptomyces badius (ACCC 40172) which is a freeze-dried strain and a market product. The step (B) includes:    (A) cleaning ampule tube by absorbent cotton soaked with 75% of alcohol in condition of keeping freeze-dried and stored microbial strains sterile, heating top end by flame, and dropping less sterile water to heated top end to break it;    (B) knocking off broken ampule tube top end by tweezers, and absorbing 0.3-0.5 mL of liquid culture medium by sterile suction tube;    (C) dropping in ampule tube, and slightly shaking to dissolve freeze-dried strains to present suspended states; and    (D) absorbing all strain suspensions and transplanting in 2 bevel culture medium test tubes, culturing and activating at suggested temperature to obtain good growth and breeding capacity.    The step (C) includes: (i) providing CM-M4 culture medium for C. themocellum which comprises (g): potassium dihydrogen phosphate (KH2PO4) (0.5), dipotassium hydrogen phosphate trihydrate (K2HPO4.3H+2O) (1), urea (2), magnesium chloride hexahydrate (MgCl2.6H2O) (0.5), calcium chloride dihydrate (CaCl2.2H2O) (0.05), ferrous sulfate heptahydrate (FeSO4.7H2O) (1.25), morpholino propane sulfonate (10), resazurin (1), yeast extract (6), glucose (5), cyeteine-HCl.H2O (1), and distilled water (1000 mL) (pH is 7.2), performing sterilization for 20 minutes at 121.3 degrees C with 1.05 kg/cm2 of speed, and inoculating C. themocellum in a sterile condition and placed in a thermostat, where temperature is kept at 55 degrees C and anaerobic culture is performed for 72 hours; (ii) providing nutrient bouillon culture medium for B. licheniformis which comprises (g): peptone (10), beef extract (3), sodium chloride (5), and distilled water (1000 mL) (pH is 7), performing sterilization for 20 minutes at 121.3 degrees C with 1.05 kg/cm2 of speed, and inoculating B. licheniformisin sterile condition and placed in thermostat, where temperature is kept at 30 degrees C and anaerobic culture is performed for 72 hours; (iii) providing de Man, Rogosa and Sharpe (MRS) culture medium for L. acidophilus which comprises (g): peptone (10), beef extract (5), yeast extract powder (4), glucose (20), Tween 80 (RTM: polyoxyethylene (20) sorbitan monooleate) (1.08), KH2PO4 (2), sodium acetate (5), triammonium citrate (2), ,magnesium sulfate heptahydrate (MgSO4.7H2O) (0.2), manganese sulfate tetrahydrate (MnSO4.4H2O) (0.05), and distilled water (1000 mL) (pH is 6.2 plus minus 0.2), performing sterilization for 20 minutes at 121.3 degrees C with 1.05 kg/cm2 of speed, and inoculating L. acidophilus in a sterile condition and placed in thermostat, where temperature is kept at 28 degrees C and anaerobic culture is performed for 72 hours; and (iv) providing yeast wash culture medium for S. badius which comprises (g): glucose (4), yeast extract (4), malt extract (10), calcium carbonate (CaCO3) (2), distilled water (1000 mL) (pH is 7.2), performing sterilization for 20 minutes at 121.3 degrees C with 1.05 kg/cm2 of speed, and inoculating S. badius in sterile condition and placed in thermostat, where temperature is kept at 26 degrees C and anaerobic culture is performed for 72 hours. The step (D) includes blending lignite (5-10%), vinegar residue (50-65%), sawdust or straw (20-25%), shale (8-10%), magnesium sulfate (1-2%), zinc sulfate (0.5-1%), borax (0.5-1%) and microbial strains (0.1-0.2%) and uniformly stirring. The step (E) includes naturally stacking on ground to ferment and fermenting to conical or long-arch, where pile width is 2.5 mm, height is 1.2 m, total fermentation mass of single pile is not less than 500 kg, preferably is greater than 5000 kg. The step (F) includes turning pile manually or mechanically and supplementing oxygen to make materials uniform and make fermentation adequate. The step (G) includes obtaining fermented biologic organic fertilizer is black (brown) and powder, where a granulation device is used for producing ball shapes with 3-5 mm of diameters or cylindrical shapes with 3-5 mm of diameters and 5-8 mm of lengths. The step (H) includes carrying out drying, where material temperature is not higher than 60 degrees C and drying time is not greater than 10 minutes. The step (I) includes measuring living bacteria count by plate counting method, where organic material, water content, pH value, colibacillus value, ascaris ova mortality, chromium and oxides, cadmium and oxides, mercury and oxides, arsenic and oxides, lead and oxides are measured by stated method in NY884-2004. The step (J) includes measuring by electronic scale or platform scale with 40 plus minus 0.04 kg or 50 plus minus 0.05 kg of error and packaging by plastic woven bag or compression-molded paper bag. The dosage per 666.7 m2 is 80-500 kg. The product is used as base fertilizer broadcasted or furrow-applied.