"Vermicompost outperforms any commercial fertilizer I know of." continues [Professor. Clive A.] Edwards, who began his earthworm research in his native England in the early 1970s before coming to Ohio State. "I think the key factor is microbial activity. Research that I and others have done shows that microbial activity in worm castings is 10 to 20 times higher than in the soil and organic matter that the worm ingests." Dr. Clive Edwards, in "Worldwide Progress in Vermicomposting" by Gene Logsdon in BioCycle October 1994, p. 63