Effect of Vermicomposting on Characteristics of Cattle Manure

Vermicomposting is a new type technique for treating organic waste in the world, but little information on the characteristics of vermicomposts can be found. Eisenia foetida (a popular commercial variety) was used and inoculated in the raw cattle manure under optimal moisture and inoculation density in laboratory at 20℃ . Characteristics of cattle manure were studied after vermicomposting for two months, using the raw uncomposted cattle manure without earthworm and natural composting cattle manure as the controls. The results showed that the Eisenia foetida developed and reproduced well in the 60 incubation days. Eisenia foetida increased significantly the content of mineral nitrogen and available phosphorus, promoted the activity of alkaline phosphatase, decreased the number of microbial and the activity of urease, but had no significant effect on sucrase in the raw uncomposted cattle manure. Numbers of bacteria significantly increased in the vermicomposting treatment for the first 15 days, while fungi and actinomyces changed insignificantly between the two treatments, which implied that the earthworm was favorable to the maturity of raw cattle manure and increased the mineralization. Compared with natural composting without earthworm, vermicomposting significantly increased the content of mineral nitrogen and available potassium, microbial biomass C and N and the activity of urease, alkaline phosphatase and invertase. These results suggested that vermicomposting was a better way for treating organic waste, by decreasing the nutrient loss and enhancing the active matter in the composting process.