Screening of Fermentation Starters for Organic Fertilizer Composted from Chicken Manure

In order to find fermentation starters that can promote rapid and effective composting of chicken manure, shorten the fermentation period, and improve the compost quality, fermentation starters with different microbial combination ratios (C1, C2, C3, C4 and C5) were designed and fermentation experiment was carried out on these five fermentation starters, commercially available organic fertilizer starter (SS), and chicken manure without inoculating fermentation starter. In the process of the fermentation, the changes in the fermentation temperature, water content and pH value were monitored; the effects of organic manure on the germination rate and growth of rapeseed seeds were measured; viable count, water content, and pH value of prepared fermentation starters were measured; main indicators (organic matter, nitrogen, phosphorus, and potassium) of organic fertilizer generated from fermentation were measured. From the indicators, the formula C3 and C4 were better, in the beginning of fermentation, the temperature rose rapidly, and it reached 40 ℃ in the second day; the water content dropped to below 35% in the 18th day; the pH value underwent the process of declining – rising – stable, and the overall value showed slight rise, but the change was not great (0-0.5). C3 and C4 fermentation products had better effects on the germination and growth of rapeseeds. The germination rate of the rapeseed seeds was 100% and 97.5% and the bud length was 15.94 mm and 14.57 mm, respectively, and the root length was 45.97 mm and 39.44 mm, respectively. The content of organic matter in fermented organic manure was 86.62% and 85.17% respectively, and the total content of nitrogen, phosphorus and potassium was 8.85% and 8.22% respectively, and the pH was 7.5 and 8.0 respectively. All of these complied with the industry standard NY525-2012 (organic matter ≥ 45%, and nitrogen, phosphorus, and potassium ≥ 5%, pH 5.5-8.5). The fermentation of fresh chicken manure was completed within 20 days, conforming to the requirements of large-scale organic fertilizer production factory for composting chicken manure into organic fertilizer.