Dale Overton, Overton Environmental Enterprises - Compost ...

Putting Worms to Work
in Organics Recycling
By Dale Overton,
Director

Overview
1. Organic Waste Streams
2. Vermitechnology – Putting Worms to Work
3. Implementing Vermitechnology
4. Environmental Considerations
5. Equipment and Processing Techniques
6. Worm Processing Flow Chart
7. References

Organic Waste Streams
1. Residential Waste
- Kitchen scraps, paper products and yard waste
(high Nitrogen content, moderate Carbon
content)

Landfill Component Breakdown

Organic Waste Streams
2. Commercial Waste
- Restaurant waste
(high Nitrogen content, low Carbon content)
- Industrial food processing waste
(high Nitrogen content, low Carbon content)
- Pulp/paper and forestry waste
(low Nitrogen content, high Carbon content)

Commercial Waste Streams
Grocery store waste in a landfill
Paper mill sludge in an tailings pond

Organic Waste Streams
3. Agricultural Waste
-
Hay (low Nitrogen content, high Carbon content)
-
Green materials (high Nitrogen content, low Carbon content)
-
Manure (high Nitrogen content, low Carbon content)
-
Agricultural processing waste
(high Nitrogen content, moderate Carbon content)

Agricultural Waste Streams
Manure being composted with hay
Old rotting hay bales that little the rural
landscape

Click icon to add picture
4. Municipal Biosolids Waste
-
High Nitrogen content and moderate Carbon content
-
High levels of other compounds
(pharmaceuticals, antibiotics and toxic metals)

Current Organic Waste
Handling Methods
1. Land filling – The majority of organic waste is being
buried in landfills across the world
2. Burning – Many rural landfill operators and other
industries burn organic matter to make room for more
waste in landfills/waste compounds
3. Composting – Fortunately, many cities in Europe,
United States and Canada have implemented
municipal composting programs

Vermitechology
Putting Worms to Work in Organics
Recycling
Vermitechnology – The use of surface and subsurface local
varieties of earthworms in composting and soil management
(Ansari and Ismail, 2009)

Why Vermitechnology?
- “Earthworms are the intestines of the earth and
restoring agents of the soil” Aristotle – 382 – 322 BC
- Earthworms process all forms of organic matter
- Earthworms promote the growth of beneficial soil
organisms
- Earthworms recycle and stabilize nutrients effectively
and efficiently

Benefits of Vermitechnology
- Worms “mechanically” mix and aerate organic debris piles
- Worms are robust and can handle a wide variety of waste
streams
- Worms can process large quantities of waste in a short time

Benefits of Vermitechnology
- Worms can process up to 2x their weight in food per day
- Low long term operational costs
- Create a stable low cost, slow release organic fertilizer

Where can
Vermitechnology be Used?
- Residentially – Household organic waste reduction
- Municipally – Landfill composting operations and
management of biosolids waste
- Commercially – Food service and food processing facilities
- Agriculturally – Manure, green waste and hay management

Implementing
Vermitechnologies

Earthworms are Livestock
- Worms are a form of livestock
- In cold climates worms must be reared indoors during
winter months (or year round)
- Worms require maintenance
(watering, feeding, bedding and breeding)

What Species are Best?
Native local earthworms are the best choice if suited for
composting
1. Tropical and sub tropical climates
ü
ü
ü
ü
African Night Crawler – Eudrilus eugeniae
Tiger Worms – Eisenia andreia
Indian Blue Worm – Perionyx excavatus
Other local worms

What Species are Best?
2. In Northern climates the two most common species for
composting include
ü
ü
ü
Red Wiggler – Eisenia foetida
European Night Crawler – Eisenia hortensis
Canadian Night Crawler – Lumbricus terrestris

Environmental Considerations
1. Temperature
ü Most worms are most active between 5 and 25
degrees
2. Bedding
ü
ü
Bed construction very important
Base materials – peat, coco choir, soil, hay, compost

Environmental Considerations
3. pH – Potential Hydrogen
ü
ü
ü
Greatly affects nutrient chemistry and transfer in
soil systems
Important for all aspects of worm development
and reproduction
Neutral pH (6.5-7.5) promotes the highest
fecundity and growth rates of earthworms

Environmental Considerations
4. Moisture
ü
Bedding should be kept between 70-75% moisture
for optimum growth
5. Feedstock
ü
ü
Vegetable and other food waste, grain, manure,
biosolids, leaf little and other highly abundant
waste streams
Feedstock should contain 17% protein for optimal
growth and reproduction

Other Considerations
Reproduction
ü
Earthworms can reproduce at high rates if
conditions allow
ü
Earthworms reach sexual maturity between 28-
95 days
Cycles
ü
ü
Understand the growth patterns of worms
Keep immature and mature worms separated

Reproductive Capacity of
Useful Species
Table 1 – Describing the reproductive capacity of three common composting worms
Species
Sexual
Maturity
Time
(days)
No. 0f
Cocoons
Cocoon
Hatching
Time
(days)
Egg
Maturit
y
(days)
Hatching
Success
(%)
No. of
offspr
ing
Net
reprorate/
week
E. Fetida 53-76 3.8 32-73 85-149 83.2 3.3 10.4
E.
eugeniae
P.
excavatus
32-95 3.6 13-27 43-122 81 2.3 6.7
28-56 19.5 16-21 44-71 90.7 1.1 19.4
D. veneta 57-86 1.6 40-126 97-214 81.2 1.1 1.4
Credit – Sinha et al. - 2009

Vermicompost/Castings
ü
ü
ü
Vermicompost (castings) is the end material excreted by
earthworms
It is a fertilizer and soil conditioner of the highest value
(2 - 3.5% N, 1.5 - 2% P, 1 - 1.5% K plus micronutrients)
It contains many varieties of plant growth promoting
microbes

Vermicompost/Castings
ü
ü
ü
It contains enzymes and plant growth regulators
(hormones)
It replaces chemical fertility and restores soil health
It reduces disease and environmental stress

Growth Trial Example
12
10
8
6
4
2
0
Chart 1 – The growth and development of Okra plants in a potted
experiment. Results obtained after 120 days of growth. Earthworms (EW),
Vermicompost (VC), Synthetic Fertilizer (NPK-Fert), control. Credit – Sinha
et al. - 2009

Markets
ü Retail
ü Agricultural
ü Land Reclamation
ü Landscape Management

Worm Processing Flow Chart

Processing Equipment and
Facility Requirements
Worm housing and processing equipment are vital to a
vermitechnology operation
- Housing should allow for easy maintenance and
processing
- Processing equipment should include screening and
separation of castings, eggs and large worms
- Batch mixer to blend bedding constituents

Overton Environmental
Enterprises Operation

The Harbingers of Life in
the Soil

References
Ansari A. A. 2008. Effect of Vermicompost on the
Productivity of Potato (Solanum tuberosum), Spinach
(Spinacia oleracea) and Turinp (Brassica campestris).
World of Agri. Sci. 4(3) 333-336
Darwin C. 1881. The Fermentation of Vegetable
Moulds Through the Action of Worms. Murray
Publications London
Sinha R.K., Heart S., Valani D. and Chauhan K. 2009.
Vermiculture and Sustainable Agriculutre. Am-Euras.
J. Agric & Environ. Sci. 5(S) 01-55.