Starting a piggery worm farm
When starting a piggery worm farm, the best approach is to begin with a couple of small worm beds. Once you have refined your worm husbandry and management practices, you can move onto larger-scale worm farming.
Building worm beds
Worm beds can be:
- rectangular plots
- long windrows (heaps) on the ground
- raised beds.
Suitable bed construction materials include:
- unoiled hardwood
- treated pine
- clay banks.
Worm beds can be small or large, depending on the size of your piggery and the size of the worm farm you would like to establish.
Small worm beds
Small worm beds are suitable for smaller operations. These beds should generally be around:
- 1m wide (making it easy to reach across them for management tasks)
- 2m long
- 30cm deep.
If you are using a bobcat to construct windrows, bed widths are generally the width of the bucket.
You will also need:
- 1m aisles between beds to allow for equipment access and bed management
- an anti-crawl barrier ('crawl trap') either side of the bed area to prevent large numbers of worms escaping.
Most small worm beds are rectangular plots or windrows on the ground. They can be placed directly on soil, but a concrete or other impervious base is ideal (although more expensive).
Large worm beds
Commercial worm farms generally use large worm beds. These can be extended rectangular plots, long windrows, or more sophisticated raised beds. Raised worm beds allow for easier separation of the castings by allowing the dry castings to fall out of the bottom of the bed.
Shelter and drainage for worm beds
All worm beds require shelter to protect worms from sun, wind and rain. Sheds provide the best shelter for worm farms. An insulated shed will also protect your worm farm from temperature extremes.
However, worm farming has also been successful in open-air beds, which are a less expensive option than building a shed. Open-air beds can be protected with shade cloth.
Worm beds also need good drainage so your worms don't become waterlogged. Place drainage holes at the base of your beds (e.g. in brickwork or between timber planks). Bear in mind that any drainage or leachate from the beds will need to be collected or contained.
Environmental buffers for worm beds
A buffer between your worm farm and any nearby water resources (surface and ground water) will protect those water resources from possible contamination. You should also include a buffer between the worm farm and any neighbouring houses to minimise the impact of any odour associated with raw materials (such as manure).
The size of the buffer required will depend on the separation guidelines for Queensland piggeries (PDF, 260KB) and your local council's recommendations.
Preparing suitable bedding for worms
Your worm beds should be filled with appropriate bedding before any worms are introduced. The best bedding for worms should incorporate:
- wet newspaper or cardboard, torn into strips or shredded
- mature compost.
Other suitable bedding materials that can be added include:
- dead leaves
- peat moss.
Combine these materials into a loose mix, and leave them to sit for a few days before stocking your worm bed. This will give your bedding time to reach the ideal operating temperature, moisture conditions and pH balance for worms.
Stocking your worm farm
Best worm species for worm farms
The best species for worm farms are generally:
- Eisenia foetida (commonly known as redworm, brandling worm or tiger worm)
- Lumbricus rubellus.
In the wild, these species occur naturally in the organically rich surface layer of soil. In contrast, the common or garden worm (Lumbricus terrestis) is a burrowing worm that requires large amounts of soil to survive. It is not suitable for worm farming.
Stocking rates for worm farms
Each 1m x 2m x 30cm worm bed should be stocked with about 1,000 mature worms (which should weigh a total of around 0.5 kg).
Introducing worms to a worm farm
The best way to introduce worms to a worm bed is to:
- spread the worms gently across the surface of the bed
- cover the worms with organic matter from the sides of the bed, keeping the covering material loose so the worms can move around freely
- cover the bed with hessian bags or carpet underlay to help keep light out and maintain the right temperature and moisture.