| 【Objective】The suitable C/N ratio and extraction time for producing water-soluble organic carbon
fertilizer from discarded rice straw and peanut bran fermented by different commercial microbial fermentation agents were
studied, and the suitable fermentation agent was selected.【Method】Rice straw and peanut bran were used as mixed raw
materials, and the C/N ratio was 25∶1 and 40∶1. Six kinds of commercial microbial fermentation agents were used for
solid-state fermentation and the organic carbon contents in the fermentation products were determined. Then, the water-soluble organic fertilizer was prepared by leaching, the extraction efficiency and extraction amount water-soluble carbon
were determined, and the suitable C/N ratio, fermentation agent and extraction time were identified by multivariate analysis
of variance.【Result】The organic carbon content, water-soluble organic carbon extraction rate and amount of fermentation
product with 25∶1 C/N ratio were higher than those with 40∶1 C/N ratio. The organic carbon content in the mixed
fermentation product of“fertilizer microorganism”from Hubei and the“manure-fertilizer-grass-feed multiple cycle cascade
utilization comprehensive supporting starter”from Hunan with 25∶1 C/N ratio was the highest. However, after leaching for 12
hours, water-soluble organic carbon extraction rate and amount of the mixed fermentation product of“compost fermentation
bacteria organic fermentation agent”with 25∶1 C/N ratio from Guangzhou was the highest, followed by that of“fertilizer
microorganism”from Hubei after leaching for 24 hours. For the mixture of rice straw and peanut bran with 25∶1 C/N ratio
fermented by “compost fermentation bacteria organic material starter”, the organic carbon content in fermentation product
was 177.56 g/kg, and water-soluble organic carbon extraction amount and rate were 18.22 g/kg and 10.26% respectively after
extracting for 12 hours.【Conclusion】For the preparation of water- soluble organic carbon fertilizer from the mixture of rice
straw and peanut bran by fermentation with starter, the optimal C/N ratio of the mixture of rice straw and peanut bran was 25∶1,
the optimal fermentation agent was“compost fermentation bacteria organic material starter”from Guangzhou, and the optimal
extraction time was 12 h. |
