About Vermicomposting

The plough is one of the most ancient and most valuable of man’s inventions; but long before he existed the land was in fact regularly ploughed, and still continues to be thus ploughed by earth-worms.  It may be doubted whether there are many other animals which have played so important a part in the history of the world, as have these lowly organised creatures.          

– Charles Darwin, The Formation of Vegetable Mould Through the Action of Worms (1881)

Darwin, in fact, made a life study of the earthworm and hurried to publish his last work “before joining them” in death (as he liked to joke).[1]  It was the first major scientific study of earthworms, though Aristotle had written of their importance over 2000 years ago and the Chinese made the first recorded reference to them a thousand years before that in the ancient Book of Songs.[2]

As much as 50-60% of the total wastes that are deposited in landfills are organic material.[3]  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 Vermiculture 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), at the same time sending carbon into the air in the form ofmetthane (CH4) and carbon dioxide (CO2), as well as nitrogen in the form of ammonia (NH3).

Traditional composting also creates higher C/N ratios, whereas composting with earthworms (“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.[4]

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[5], while at the same time being greatly enriched with helpful microorganisms necessary for root and foliage growth.

It is more moist; improves soil porosity, structure and drainage; has a smaller particle size; and is better oxygenated than regular compost.  While it is full of nitrogen (N2), it is low in water soluble nitrogen (NH4 and NO3) and thus poses no risk of root burn. Used efficiently, one pound of mature worms (approximately 800-1,000 worms) can eat up to half a pound of organic material per day.[6]

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] Charles Darwin, as quoted in http://en.wikipedia.org/wiki/The_Formation_of Vegetable_Mould_through_the_Action_of_Worms.
[2] Li Kangmin, Vermiculture Industry in Circular Economy, as reprinted in http://www.wormdigest.org/ ?emurl=http://www.wormdigest.org/content/view/135/2/.
[3] 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.
[4] 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).
[5] Edwards, p. 14.
[6] http://www.epa.gov/wastes/conserve/rrr/composting/vermi.htm.