This article is an excerpt from Rodale Institute’s “A Simple Guide to Vermicomposting.” Click here to download the full guide.
Solid waste generation in the United States continues to rise at a steady rate. According to the US Environmental Protection Agency, Americans generated about 254 million tons of trash in 2013, which is the equivalent of 4.40 pounds per person per day.
Yard debris and food waste combined account for nearly 30% of the materials disposed in US landfills. These materials can be easily composted in municipal and backyard composting systems and fortunately, composting collection programs have been increasing with increasing waste generation. However, backyard composting may not be an option for many individuals that wish to divert their materials from the landfill because they lack yard space, time or energy or else live in a rental unit; therefore, vermicomposting becomes an attractive alternative. What’s more, vermicomposting can be a powerful educational tool for teaching children about decomposition, microbiology, earthworms and the importance of managing organic residuals such as food waste at home.
Why Vermicompost?
Vermicompost is the product of earthworm digestion and aerobic decomposition using the activities of micro- and macroorganisms at room temperature. Vermicomposting, or worm composting, produces a rich organic soil amendment containing a diversity of plant nutrients and beneficial microorganisms.
There are several benefits for vermicomposting but the two most popular are (1) diverting organic residuals from the landfill and reducing trash collection fees and (2) creating resources from waste materials.
Vermicomposting can be a fun activity for school children, and vermicompost can be utilized in gardens to promote plant growth. Vermicompost can be mixed with potting media at a rate of 10% by volume or else added directly into your soil; both options will provide plants with valuable organic matter, nutrients, and a diversity of beneficial microbes.
Earthworm Biology
Typical earthworms that you find in your garden are not suitable for vermicomposting. These are soil-dwelling worms that do not process large amounts of food waste and don’t reproduce well in confined spaces. Instead, worms commonly known as redworms or red wigglers are preferred because they reproduce rapidly, are communal and tend to remain on the surface while feeding.
There are several species of vermicomposting worms but the most common are Eisenia fetida and E. andrei. Red wigglers are hermaphrodites having both male and female reproductive parts; however, it still requires two worms to mate with each worm donating sperm to the other worm.
Under ideal conditions, a worm bin population can double about every 2 months (4-6 weeks from cocoon to emergence and 6-8 weeks from emergence to maturity). The “band” around a worm, known as the clitellum, indicates maturity and is reproductively active. Cocoons are about the size of a match stick head, turning pearly white to brown as they develop until one to several baby worms hatch.
Red wigglers require similar conditions as humans for growth – they prefer room temperature (55-85°F) and adequate moisture. The population of a worm bin is controlled through nutrient/food availability and space requirements.
For the full guide click here.