Worm School for Students
Introducing the Worm
Charles Darwin was fascinated by worms. In his book "The Formation of Vegetable Mould by the Action of Worms" (1896), Darwin wrote "Worms have played a more important part in the history of the world than most persons would at first suppose."
One of an earthworm’s most important roles is to recycle organic waste such as food scraps into a high quality soil conditioner. But how do they do it?
Earthworm Biology
An earthworm’s anatomy
As everyone knows, earthworms usually look red or pink. Their bodies are long, cylindrical, and divided into rings or segments. But when you take a closer look, you’ll see that adults have a clitellum. The clitellum is a thickened area on the upper and side surfaces of the body that is usually paler than the rest of the worm. For this reason it’s often called a saddle.
Unlike humans, earthworms have no special breathing organs. Oxygen is absorbed and waste gases are passed through the skin via a network of fine blood vessels just under the skin surface.
To enable this to happen, gland cells secrete mucus that moistens the body’s surface. The mucus also lubricates the body so that the worm can move through soil.
Quite simply, an earthworm’s body is made up of one tube inside another. The outer tube is the muscular body wall, and the inner tube the digestive system, with a fluid filled space to separate them.
How earthworms digest food
The earthworm’s digestive system is essentially an unbranched tube that runs from its mouth at one end of its body to the anus at the other end. Just inside the mouth the tube expands into a strongly muscular pharynx. The pharynx turns inside out so that it protrudes through the mouth to surround and grasp pieces of food. The food is then pulled back into the mouth and passes back into the worms' gizzard. The food is ground down by the gizzard The earthworm’s digestive system is essentially an unbranched tube that runs from its mouth at one end of its body to the anus at the other end. Just inside the mouth the tube expands into a strongly muscular pharynx. The pharynx turns inside out so that it protrudes through the mouth to surround and grasp pieces of food. The food is then pulled back into the mouth and passes back into the worms' gizzard. The food is ground down by the gizzard
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Left: Scanning electron Microscope photograph of an earthworm showing details of segment and setae. Magnification x 11.
Right: Close-up of earthworm setae. Magnification x 125.
How earthworms move
An earthworm moves by bunching up like a spring then using the bristles on its back like an anchor, to push itself forward. Sounds simple? It’s actually quite complex and involves a set of co-ordinated actions and reactions that include the earthworms' muscles, small bristles on the body wall (called setae), and the fluid filled body cavity.
An earthworm has a brain and several hearts!
The earthworm’s brain is a small bundle of nerve tissue located on top of and right at the front of the pharynx. It is connected to a nerve cord that runs along the body cavity under the gut. The nerve cord provides nerves for muscles and other organs in each segment of the earthworm’s body.
Blood is pumped throughout a worms' body by anywhere between 3-5 pairs of hearts! A pair of hearts surrounds the oesophagus in each of several successive segments of the earthworm.
Breeding
An earthworm has both male and female reproductive organs. Most species have two pairs of testes (male organs) and one pair of ovaries (female organs).
During mating, two worms align themselves in a head to tail position, and touch each other over a length of around 35 front segments. They produce a thick layer of mucus, discharge sperm cells, then separate from each other.
A broad ring forms around each worms' body. The earthworm works itself back through the ring and in doing so, leaves behind the eggs and sperm cells. Eventually, the ring passes over the worms' head to form a cocoon, which houses a number of eggs. Baby worms emerge from the cocoon after a period of approximately three weeks.
From: Earthworms for Gardeners and Fisherman. CSIRO 1978. East Melbourne.
Worms Facts
- VERMICULTURE refers to the management and breeding of worms
- Worms are one of nature’s ultimate recyclers
- They can live for 15 years or more
- They have both male and female reproductive organs
- Their eggs can survive dry and harsh conditions for long periods of time
- They can be bred easily at home or at school
- They can be used to recycle organic waste from your kitchen into valuable fertiliser
- They produce castings (worm poo!) which have a neutral pH (around 7)
- Their castings increase the amount of nutrient available to your plants by up to 10 times
- Their castings increase yields (or production) from crops and pastures
- They increase the level of essential microbial activity in the soil
- They can consume their own body weight in food every day
- They double in population every 2-3 months in ideal conditions
Which Worms are for You?
There are about 350 species of earthworms in Australia living in many different habits so it is important to make sure you have the right earthworms for the project you are getting underway. The CSIRO has described the broad categories of earthworms as:
Composters - reared for composting organic wastes, fish bait, and producing soil conditioner.
Earthworkers - live 'free' in the soil, improve soil conditions and promote plant growth.
To get a Can-O-Worms started, you need 'composters'. Tigers, Reds and Blues are the most common 'composters'. They should be kept in captivity as they only survive in an organic-rich environment where food and moisture are carefully maintained throughout the year. These worms are not suited to soils so you wont find them in the garden!
'Composters' in your Can-O-Worms will produce worm manure called castings or vermicompost which can be used to improve the soil in your garden or in pots. For example, you can add castings to potting mixtures, place them around plants as a top dress fertilizer, or add them to seed raising mixes. The castings can also be used to feed earthworker worms, which will work it well into your garden.
Worms are nature's own recyclers. They convert your kitchen scraps and garden waste into nutrient-rich plant food for free!
- Create a home with a Tumbleweed Can-O-Worms
Put an 8cm layer of bedding material (worm castings, compost or peat moss) on a layer of hessian material or several sheets of newspaper in the first working tray.
Add at least 1000 worms (250 gms) to the bedding material and cover them with a wet hessian bag or newspaper.
Allow your worms a few days to settle in to their new home then add a handful of food scraps to the surface feeding area. Replace the hessian or paper on top.
Place your Can-O-Worms in a cool dry area away from the hot sun.
- Provide them with food and drinks
You can feed your worms with any food scraps, EXCEPT meat, or very small quantities of decomposting organic matter (eg. manures, grass clippings, leaves, etc). Variety is the key!
Vegetable scraps are about 80% water content so if most of the food you give your worms is vegetable matter, you won’t need to provide them with any water. Manage the amount of food you give your worms so that you keep just ahead of their rate of consumption.
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Manage your worms’ habitat
Add a sprinkling of lime, wood ash or dolomite every few weeks to maintain the ideal habitat for your worms.
When the top working tray is full, which will take about 4-6 months, take the bottom working tray and empty the contents on your garden then return that tray to the top.
Refer to the Instruction Manual that came with your Can-O-Worms for more detailed instructions or the Can-O-Worms FAQ.
Minimising Waste
What is waste?
Waste, or garbage, is made up of all the unwanted products in human societies. We all produce it – and we all face a problem when it comes to disposing of it.
While the total amount of waste produced per person has increased with time, some materials, such as organic waste and paper, have increased significantly. In Australia, the problem is being compounded by a steadily increasing population – all of whom produce their own amount of garbage!
Highlight :
Australian households currently produce more than two million tonnes of food and garden waste each year - or about 145 kilograms per person. However, only about 200,000 tonnes is currently composted in home composting units or worm farms. (Industry Commission Report Recycling Vol.11 pp179-180)
Recycling minimises waste
The good news is that much of the waste we produce can be recycled or composted. Waste derived from food or the garden, which is known as organic material, can be composted in backyard compost bins or fed to the ever-hungry composter worms in your worm farm.
Packaging materials, which make up about one-third of domestic rubbish, can also be reused or recycled. Importantly, you can reduce the amount of packaging produced ion the first place, by shopping more selectively. Choose products that contain less packaging to encourage manufacturers to use less packaging. This, in turn, will help reduce consumption of energy and natural resources.
There are many non organic materials that can be recycled:
Paper
Making recycled paper uses one sixth of the electricity needed to operate a virgin mechanical pulp mill (a mill used to produce non recycled paper) and may contribute to the conservation of native forests in Australia and overseas. By recycling paper, you’ll help Australia save money, space and energy.
Glass
Glass can be recycled repeatedly by crushing it then adding it to a furnace with a mixture of sand, soda and lime. This process saves the energy and resources used to make new glass.
In Australia, about 40% of glass containers (bottles and jars) are collected for recycling.
Plastic
About 1,000,000 tonnes of plastic is used in Australia each year – and about half of it ends up as waste. Householders alone throw away 320,000 tonnes of waste plastic each year, most of which is short life packaging materials. Recycling plastics saves considerable amounts of energy, and landfill space at our landfill sites.
You can reduce the amount of plastic your household uses by carefully selecting the products you purchase.
Highlight:
RELN is one of Australia’s largest consumers of recycled plastic. We melt down consumer plastics including car battery cases and old money notes then turn the bi-product into Tumbleweed Compost Tumblers, Can-O-Worms and much more.
Aluminium
Used aluminium products can be recycled easily by melting them in large furnaces. What’s more, recycling aluminium takes just five per cent of the energy required to make new aluminium from bauxite…so recycling one tonne of aluminium saves five tonnes of bauxite!
(Adapted from Waste Matters - Gould League)
