Abstract: To address the problems of high raw material cost, complex process and limited application by small and medium-sized farmers in the production of traditional EM(effective microorganisms) agent, a two-stage fermentation preparation technology of compound microbial fertilizer was developed in combination with the concept of agricultural waste resource utilization. Using deep well water, waste molasses and sugar residue as the main raw materials, the “pre-fermentation + expanded fermentation” process was adopted, and the EM agent gradient expansion culture technology was used to achieve high-density proliferation of the microbial community.The results showed that compared with the traditional brown sugar fermentation process, this process required no high-temperature sterilization, reduced equipment investment by 60%, lowered raw material cost by 66.47%, and achieved a fermentation success rate of 100%. Field experiments showed that compound microbial fertilizer significantly improved soil organic matter utilization rate and the bioavailability of nitrogen, phosphorus and potassium. Compared with the conventional chemical fertilizer treatment, vegetable root biomass, average yield and vitamin C content increased by 35.0%, 27.4% and 16.2%, respectively, while nitrate content, incidence of soil-borne diseases and chemical pesticide use decreased by 39.5%, 66.3% and 45.2%, respectively. This technology was easy to operate and low in cost, and achieved the dual goals of agricultural waste resource utilization and green production of facility vegetables.

Key words: two-stage fermentation, compound microbial fertilizer, research and development, agricultural waste, facility vegetables, green production