Science of Vermiculture

As much as 50-60% of the total wastes that are deposited in landfills are organic material.[1]  Moreover, it is estimated that the largest single component of landfill is waste from our kitchens, which in turn is the largest producer of methane gas (CH4), a significant contributor to global warming.  NewSoil LLC harnesses this immense and wasted source of energy by recycling it through the burgeoning science of vermiculture.  Vermiculture exploits one of nature’s best means of decomposition of organic matter:  the earthworm.

The voracious, burrowing and prolific earthworm processes organic materials far more quickly than most conventional composting techniques, as measured imperically by a rate called the carbon-to-nitrogen ratio.  Composting by traditional means naturally employs higher thermolythic activity (or decomposition of solids through heat), creating higher C/N ratios, whereas composting with earthworms (or “vermicomposting”) can lower both the maturation time and the C/N ratio. In a study using cow manure, the resultant compost had a C/N ratio of 18:1 while the vermicompost had a corresponding C/N ration of 11:1.[2]

Besides taking longer to mature and containing less nitrogen, traditionally-created compost also has lower microbial content, since the thermolythic process necessary to cure the compost kills any helpful microbes (as well as dangerous pathogens – a concern inherent to processing waste).  Vermicompost is likewise devoid of pathogens[3], while at the same time being greatly enriched with helpful microorganisms, Plus it is more moist, has a smaller particle size and is better oxygenated than regular compost.

Used efficiently, one pound of mature worms (approximately 800-1,000 worms) can eat up to half a pound of organic material per day.[4]  Worm “castings” is the name for waste that has been entirely processed by the digestive systems of worms.  It has an even lower C/N ration than vermicompost, so much so that it needs to be mixed with more carbon rich compost before it is added to plant soil.  Also, “worm tea” or the liquid extracted from worm castings is proving one of the most effective organic liquid fertilizers available.

[1] Clive A. Edwards, “Introduction, History, and Potential of Vermicomposting Technology,” Vermiculture Technology Easthworms, Organic Wastes and Environmental Management, ed. By Clive A. Edwards, Norman Q. Arancon and Rhonda Sherman (2011, CRC Press), p. 1.

[2] Cristina Lazcano, María Gómez-Brandón and Jorge Domímguez, “Comparison of the effectiveness of composting and vermicomposting for the biological stabilization of cattle manure,” Chemosphere 72 (2008), p. 1014 (http://www.elsevier.com/locate/chemosphere).

[3] Edwards, p. 14.

[4] http://www.epa.gov/wastes/conserve/rrr/composting/vermi.htm.