Effects of Vermibeds with Different C/N Ratios on the Growth and Fecundity of Eisenia foetida

Comparative studies were performed to evaluate the growth and fecundity of earthworm, Eisenia foetida, in the combination of cattle manure and rice straw with different C/N ratios under laboratory condition. The observations indicated that the biomass of E. foetida was significantly higher in cattle manure with C/N ratio of 21.8 and 80% cattle manure +20% rice straw with C/N ratio of 24.9 when compared to other treatments at 30, 60, 90 days. Moreover, the population of worms in 60% cattle manure+40% rice straw, which had a C/N ratio of 28.7, was significantly greater than that of others at 60 or 90 days, and the number of worms increased up to 324 after 90 days. The C/N ratio of vermibeds showed significantly negative relation with earthworm biomass and population. In conclusion, the optimum C/N ratio of cattle manure and rice straw combination is from 21.8 to 24.9 for E. foetida growth, and 28.7 for fecundity.