The humble earthworm has for millennia lived in our soils largely unseen, improving the quality of these materials to support the whole canopy of ecosystems above. The shear volume of soils on earth which are everyday processed by the earthworms is huge. Is it any wonder that more and more people are realizing the potential benefits from farming these creatures? In this article we explore the rise of vermicomposting.
Vermicomposting is the process of using selected species of earthworms to help compost biodegradable wastes, and stems from the established business of vermiculture (the breeding of earthworms, mainly for the fishing bait market).
While vermicomposting and traditional composting both involve the aerobic decomposition of biodegradable matter by microorganisms, there are important differences in the way the two processes are carried out. The most notable is that the temperature of composting piles can exceed 70°C; vermicomposting is carried out at relatively low temperatures (under 25°C).
When growing worms it is vitally important to keep the temperature within the soil/compost below 35°C; otherwise the earthworms will be killed.
The worms used in vermiculture are all litter dwelling species that live in the rotting litter or biodegradable matter on the surface of soils, and produce worm casts.
In traditional composting, compost piles are mixed and aerated mechanically.
In vermicomposting it is the earthworms that fragment, mix and help aerate the waste, and most of this activity includes the ingestion of the compost/soil materials, and the deposition of worm casts. In the passage through the worm the soil/compost material is mixed, healthy bacteria grow, and enzymes are produced as part of the worm’s digestive function.
The worm casts are as a result uniquely blessed with bacteria and enzymes, the action of which makes them ideally suited as a source of plant nutrients.
The best worms
The three species most commonly used in vermicomposting in the UK are Dendrobaena veneta (blue nosed worm), Eisenia fetida (tiger or brandling worm), Eisenia andrei (red tiger worm).
Eudrilus eugeniae is a tropical species grown in warmer countries.
The best vermicomposting method
The most widely used vermicomposting system, world wide, is the ‘bed’ method, which involves applying thin layers of waste material to the surface of beds containing high densities of earthworms.
New layers of waste are applied to beds on a regular basis and the earthworms move upwards into the fresh waste to feed and to process the material. Earthworm numbers increase as more waste is applied until a limiting density is reached. The earthworms are then harvested or the beds are divided.
Why so popular
In the developed world vermicomposting provides a method of waste processing which is normally very acceptable to the local community, and produces a premium and very saleable compost product.
Vermicomposted waste is also waste which will not need to be sent to landfill, and therefore has the support of national governments, and local waste planners, particularly in Europe where the EU Directive rules for waste recycling and minimisation of landfilling, will possibly result in fines being levied on some underperforming local authorities (municipalities) in some countries in the next few years. This is due to the difficulty in developing and commissioning enough waste diversion capability in all areas fast enough to comply with the EU deadlines imposed.
In the developing world, composting provides a means by which smallholders and farmers may accept suitably segregated wastes and earn an additional income from the product of vermiculture, without requiring unaffordably investment to get started.
Vermicomposting also provides a real benefit to the local economy from both the high productivity of land fertilised with vermicompost, and the reduced watering demand once the soils have become of a much higher quality arising from the land application of this type of compost.
Also developing (Third World) worm farmers gain much practical experience from their businesses, and the degree of self sufficiency, which is a necessary part of running a small vermicomposting business is a great training. It seemingly produces a breed of self respecting and capable businesspeople ready to move into other areas of the economy with their newly won skills and earnings. Such individuals and the families they support, are then very much capable of further developing the economies of their countries, and improving quality of life for all.
India is an example of a nation where this is happening, and where we have the seen economy growing by 8 to 10 % annually. Visitors to our Compost India web site will see that over seventy composting plants have been added to our list of compost facilities in India (at the time of writing) over the past 2 months, and more operators are adding their plants all the time. See http://www.compost-india.com/ .
See also our other commercial waste composting web site http://www.compost.me.uk/