Small farmers can use compost worm's to reduce organic garden and kitchen waste, whilst also minimising dependence on artificial fertilisers.
The Worms Role
A worm farm is an ideal enterprise for a small farm as it only takes up a small area. Worms in the worm farm consume organic matter as they move through the bedding material. This material is converted by the worm’s unique digestive system into a useful (liquid or solid) fertiliser.
Why set up a Worm Farm?
Home worm farming is for everyone, anyone can do it and the more people that start the quicker the environment will start to recover from all the abuse that we have done to it over the years. Compost worms are very easy to look after, they don't smell and your children will love to feed them. They will even give you free soil improving products to use around your gardens and farm whilst eliminating your organic waste at the same time.
Setting up a worm farm is easy; before you get started you will need the following:
- Worm Farm: It can be a commercial built worm farm or you can build your own, make sure that it is big enough for the amount of organic material that you want to process and the numbers of people in the house hold.
- Bedding: This is one of the most important aspects of maintaining a healthy worm farm.
You are now ready to set up your worm farm; you should follow these basic steps to ensure success.
- The first step is to give your worm farm a quick wash out to make sure that there are no chemicals present that might affect your worms, follow this by drying inside.
- Put a couple of sheets of news paper in the bottom of the worm bin to stop the fine material falling out until the worm farm is established, but still let the excess water drain out. The worms will eat this paper at a later point.
- Add moist bedding to the worm farm; make sure that you squeeze as much water out of the bedding as possible as it only has to be damp. I like to use shredded newspaper and cardboard to start a new worm farm but you can use aged manure, compost and old leaves or whatever suitable bedding may be available. Make sure that the bedding is not compacted but loose. If you have some worm compost or worm cast, I like to add a thin layer on top of the bedding.
- Gently add the worms to the surface of the bedding material. I like to start a new worm with a mixture of Red worms, Tiger worms and Blue worms, these worms are all compost worms which are surface feeders. They are the most commonly used compost worms in the vermiculture industry and are suitable for all Australian conditions. You can then add some food scraps to the worm farm and cover the food with bedding to stop pests and flies. Compost worms are surface feeders and will eat any organic matter or manure, you should monitor the amount of food you give them as excess can cause increased moisture resulting in rotting food and a bad small. Keep an eye on how fast the worms are consuming the food and only feed them as required. As your worm stock increases, so will there food requirements. I like to add a piece of damp hessian to the surface of the worm farm to keep it moist and dark. You can now leave the worms alone and let them settle into their new home, only feeding them small amounts of food to start with until you see how much they are going to eat.
Worm Farm Bedding
The most important steps in setting up a worm farm is selecting the right bedding material. Compost worms require a material to live in called bedding.
Worm bedding must:
- Retain moisture and stay moist while allowing air circulation, and drainage from excess liquids.
- Not compact, [so that there is plenty of air circulation throughout the bedding].
- Be odourless.
- Be of neutral PH.
- Not contain sharp or abrasive objects, as worms have very sensitive skin.
- Block out light, as worms are light sensitive.
Worm bedding can be made from different materials, the more variety in the bedding material the better the finished worm cast will be. Worms are very adaptable and will thrive once the right conditions are achieved. Worms will eat their bedding (around half of their daily intake will be bedding).
Suitable types of bedding include:
- Shredded paper and cardboard.
- Old garden leaves and cuttings.
- Aged compost.
- Aged Animal manures.
The bedding (particularly compost) must be aged past the heating stage, if not this heat will kill the worms. If you mix different types of bedding together there will be a vast improvement in the finished worm cast because of the various nutrients mixed in the bedding. You must also put in a small amount of sand/soil, as the worms will consume this to help their digestion, because they have no teeth. The grit in their stomach grinds up the food with muscle action.
When putting the bedding into your worm farm make sure that it is damp, not wet, just damp so that one or two drops of water runs out when you squeeze it. Once a week before you feed the worms you should lightly lift and fluff up the bedding material to create air space, this stops the bedding from compacting and helps control odour. Each week make sure that you feed the worms in a different location of the worm farm making sure that you only feed when the last feed is nearly consumed. Always make sure that the food is well covered to prevent flies. After feeding I like to apply a small amount of garden lime. This helps to keep the flies away and keep the bin smelling nice.
Sand or Soil: You will need to add a small amount of sand or soil to the worm farm; worms require this grit in their stomachs to grind up food using a muscle action as they have no teeth. This also provides decomposer bacteria to assist in the breakdown of the food source and as a food source for the worms to eat.
Harvesting Worm Casts
After all of the hard work that the worms have done consuming house hold organic waste and yard trimmings, you will have noticed that even with all the food that you have added to the worm farm that the level has not increased, and in most cases it is lower now than when you first started. If you move the top layer of material aside you will see that it has changed into a dark soil looking material. This is worm cast, or vermi cast. Worms cannot survive in worm cast, so it is now time to harvest the worm cast and reset your worm farm.
If you notice that you have large numbers of compost worms you can:
- Separate some and start another home worm farm.
- Give some away so that other families can start their own home worm farm.
- Move some to an outdoor compost pile or well mulched moist garden bed.
To complete this process follow the steps below.
- Make sure that you have some new bedding, moist and ready for your worm farm.
- Remove the top three to four inches of material from your worm farm and put it aside, as this will contain lots of worms and mostly unprocessed organic material.
- Empty your worm farm onto a large piece of clean plastic, and start to reset your worm farm - Put in a couple of sheets of newspaper to prevent the fine material falling out the drain holes.
- Put the moist bedding in and then the organic material and worms that you saved from the previous worm farm set up. [The three or four inches of material off the top of you worm farm you saved.]
Now it's the time to sort your worm cast. You should have a nice pile of worm cast, worms and some organic matter in a pile on a plastic sheet.
Option 1: Sifting with a Coarse Screen
Using this option simply put a couple of hand full's of material into a sifter, give it a few shakes and all the fine worm cast will fall through leaving only the worms and unprocessed organic material in the sifter. I then tip this in on top of the material in the worm farm, it only takes a short time to do the whole pile and you end up with a very fine pile of worm cast and the worms and unprocessed organic material back in your worm farm. The sifter that I use is just a round container with a coarse screen in the bottom that the material falls through.
Option 2: Dump and Sort with Light
Build a small pile of material, I usually build four. Place a light above the heaps so it shines down on them. The worms will then quickly bury themselves to get away from the light. Carefully remove the material off the top of each pile. As you start to see worms, stop and wait a little while and repeat the process over and over again until you only have a pile of worms left. Carefully put all of the worms back into the worm farm that you have prepared with the bedding. This method can be used with sunlight but don't expose worms to direct sunlight, as it will kill them.
Option 3: Migration
In this method you do not have to remove the cast from the worm farm to harvest it. Simply move all of the material in the worm farm onto one side and then reset the empty side with moist bedding. Now only feed and apply moisture to the new bedded side as required, the worms will move across to this new side. After 4-6 weeks all of the worms and newborn worms from the hatched eggs will be on the new side. You can now remove all the old material and put new bedding in this empty side. Any unprocessed material can then be returned onto the top of the worm farms bedding and you can start feeding on either side once again.
This information is courtesy of Wormtec.
Wormtec are a family owned and operated commercial worm farm and organic fertiliser producer located on the Gold Coast. They have various worm farming joint ventures in Southern Queensland, including the recycling of animal manures on farms and green waste from lawn mowing contractors.