NOVELTY - A soil-free plug seedling substrate comprises matrix and additive. The matrix is fully fermented by vermiculite decomposed organic matrix material mixed at volume ratio of 1:1. The additive comprises 3-5 kg/m3 biological organic fertilizer, 0.2-0.3 kg/m3 potassium sulfate, 0.5-0.6 kg/m3 diammonium phosphate, 30-40 g/m3 50% carbendazim, and 50-60 g/m3 65% zineb powder.    USE - Soil-free plug seedling substrate.    ADVANTAGE - The method can utilize soil-producing renewable resources, reduce seedling, cultivate seedlings growth and no delaying period after planting. The substrate is suitable for long-distance transportation.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of seedling substrate comprising:    (A) crushing corncob into granule with grain diameter of 0.5-1 cm, extracting licorice slag with glycyrrhizic acid to obtain licorice extract with less than 1 cm waste residue, peeling waste cotton linter with less than 1 cm cotton fiber, and mixing at volume ratio of 1:1:2; adding 60 wt.% water, adding 10 wt.% chicken manure and 0-5 kg urea at carbon-nitrogen ratio of 25-35:1, adding with 2-3 wt.% high-efficiency degrading microbial inoculum, adjusting water content to 70-75%, uniformly stirring, covering water-proof thermal insulation material, and fermenting;    (B) mixing chicken manure, sheep manure and biogas residue at volume ratio of 1:1:1, controlling water content to 35-45%, adding 0.5 wt.% effective microorganism (EM) inoculum, uniformly mixing, fermenting at 55-65 degrees C for 7-10 days, reducing stack temperature to 30-40 degrees C, reducing water content to 20-30%, composting, crushing, sieving, adding 4.5-6 wt.% organic fertilizer in every 1000 kg EM inoculum, mixing, and uniformly stirring to obtain organic fertilizer with 25-30% organic matter content, 15% humic acid content and greater than or equal to 5% nitrogen, phosphorus and potassium content;    (C) dissolving carbendazim and zineb powder in water to obtain disinfectant solution;    (D) crushing potassium sulfate and diammonium phosphate; and    (E) mixing fermented organic matrix material and vermiculite, adding chloroform to obtain biological organic fertilizer, and uniformly mixing disinfectant solution and crushed potassium sulfate and diammonium phosphate.