Analysis and Study on Physicochemical Properties Variation in Fermentation Process of Rapeseed Meal Composting

[Objective] This study aimed to screen out the methods and indices that could quickly and accurately detect the maturity of materials through evaluating the mature status of rapeseed meal composting. [Method] The physicochemical proper- ties variation of rapeseed meal composting was analyzed by testing emission of carbon dioxide, degradation of organic matter, conductivity values, coefficient of seed germination and free amino acids during the fermentation process. [Result] In the process of fermentation, the release amount of carbon dioxide per unit time was drastically reduced at the beginning and then the change became smoothly later. The organic matter was degraded quickly and then slowed down, and the total amount of degradation was 7.34%, total degradation rated of 9.06%. The seed ger- mination coefficient showed a trend of gradual decline, and after the start of fermen- tation, the germination coefficient was below the critical coefficient of 0.8. The con- ductivity value and the free amino acid content changed significantly, which showed strong regularity, and the increase amount was close to 1 times. [Conclusion] The detection of conductivity value and free amino acid content in rapeseed meal com- posting can be used as the methods and indices for the quick and accurate detec- tion of the maturity of organic fertilizer fermentation.