Not only are worms not pathogen-infested organisms, but there is actually a growing body of evidence to suggest that worms (specifically composting worms) can actually significantly reduce populations of pathogens in waste materials.

Eastman et al. (2001) tested the effectiveness of vermicomposting for pathogen destruction in biosolids (sewage sludge from waste treatment plant). The researchers “heavily” inoculated two biosolids windrows with four different pathogens – fecal coliforms, Salmonella, enteric viruses and helminth ova. Red worms (Eisenia fetida) were then added to one of the rows at a ratio 1:1.5 (worm wt:biosolids wt) and left to process the materials. After 144 hours the row with the worms was found to contain significantly fewer pathogens than the control row. The results strongly suggest that vermicomposting could be used to achieve EPA Class A standards for biosolids.

In a 2006 BioCycle article, Craig and Ankers report on a promising ‘real world’ example of a large-scale vermicomposting system being used successfully to achieve Class A biosolids. A Pennsylvania wastewater plant has become the first in the U.S. to be granted a permit to make use of biosolids that have been
processed by worms. The plant utilizes a large-scale (semi-continuous) flow-through reactor designed by Vermitech systems (of Australia) to process biosolids ‘filter cakes’ – a material that was previously landfilled. According to the article, the resultant vermi-processed material has been well received by local vineyards, golf courses and sod producers.

There is some evidence to indicate that worms can reduce pathogens in manures as well (although this doesn’t appear to have been studied as extensively). Murry and Hinckley (1992) studied the fate of Salmonella in horse manure processed by Eisenia fetida. They observed an 8% reduction in the presence of worms, and only a 2% reduction in treatments without worms. The horse manure was completely sterilized prior to use in the
experiment, and the ratio of worms to waste was lower than in the Eastman study – potentially explaining why reductions were not as dramatic in this study.

Despite the evidence suggesting potential pathogen destruction during the vermicomposting process it is still best to use caution when dealing with materials such as manures and sewage. Part of the problem is that even if the passage through the earthworms’ gut IS destroying these organisms, how can we be sure that all the material has in fact passed through a worm? Even in the most efficient systems there will undoubtedly still be at least some unprocessed materials.

As an extra precautionary measure when using manures/sewage as worm food, I’d recommend hot composting the materials for at least a few days prior to feeding it to your worms. This has the added bonus of speeding up the process and destroying weed seeds as well.

REFERENCES

Craig, L. and S. Ankers. 2006. Vermiculture produces EQ Class A biosolids at wastewater plant. BioCycle 47(2): 42.

Eastman, B.R., Kane, P.N., Edwards, C.A., Trutek, L., Gunadi, B., Sterner, A.L. and J.R. Mobley. 2001. The effectiveness of vermiculture in human pathogen reduction for USEPA biosolids stabilization. Compost Science & Utilization 9: 38-49.

Murray, A.C. Jr and L.S. Hinckley. 2006. Vermiculture Produces EQ Class A Biosolids at Wastewater Plant. BioCycle 47(2): p.42.

At the beginning of November, the Kelowna farmer’s market is going to move inside. You will be able to find your fresh product and craft at the Parkinson Recreation Center every Saturday, all winter long from 9am to 1pm, until the end of Marsh.

The market indoor being significantly smaller, I was able to get only 2 dates so far:

-November 5th, 2011

-December 3rd, 2011

As always you welcome to call (250-864-4213) to book your vermicompost needs or order on line over the winter. We will be happy to ship to you.

Ludovic

I was wondering if you would recommend your worm farms to help compost biodegradable diapers?

Have you or any of your customers tried this and if so what have your experiences been? Is this something you would recommend doing and what would be the main things to look out for?

Any help you could give would be very much appreciated.

Thanks,
Derek

Hi Derek,

To be honest I never had the chance to have a babe around to try composting diapers. But soon it’s going to be my turn. I will become a daddy in around 2 months !

For now, I had few customers asking me about composting dog excrement. In theory it will be close to the same issues, sanitary and smell.
So please have a look at http://www.worldofworms.com/will-a-worm-farm-work-to-recycle-dog-excrement/

I would need to know more about your set up to be specific.
If you have an vemicompost indoor:
The biggest problem you will run into will be the fact that most of the diaper is fiber. Red wigglers and other composting worms will eat fiber but not as fast as food loaded with nutrients. That’s why, in your indoor vemicompost you don’t want to add fiber with every feeding. So in order to process daily diapers you will need a really big system with many pounds of worms.

More appropriate, a composter outside:
Here volume and time will not be a problem. The only problem will be potential disease if you want to use your compost/casting for your vegetable garden.
(please make sure to read my post. It will explain the reason why you need to be careful).

I hope this helps.
It’s a really interesting question. And I will be trying something out myself real soon. Please keep me posted on the option you are going with.

If you need more help to get set up, send me more info for me to know more what you’re thinking about doing. I will be happy to help you with your composting project.

Ludovic Bourdon

Hi Kristina,

I am always happy to hear about parents starting up worm composting projects with their children. I think it’s such a great way to not only educate them about environmental responsibility, but also introduce them to many interesting creatures that are far too often thought of as “creepy” or “gross” later in life.

Regarding your question, there are no strict rules as far as how much you should be feeding and how quickly the materials are being broken down (although the two ARE closely linked to one another). When first starting a bin, I recommend mixing in ample amounts of ‘food’ materials along with the bedding then letting it sit for a week or so before adding the worms. This way the bin will seem a lot more like “home” to the worms, and they will have plenty to eat for quite some time. Once the worms have been added to the system, newcomers very often become concerned about whether or not they are feeding their worms enough.

Either that or they are following guidelines such as the claim that composting worms can eat their own weight in food scraps every second day (which they certainly can). Adding 1 lb of food scraps each day to a brand new system with 2 lb of worms in it is just asking for trouble in my humble opinion.

If a bin is set up the way I described, the worms literally don’t need to be fed for weeks. I’ve completely neglected bins I’ve set up, then opened them a couple of weeks later to find an abundance of fat worms and lots of vermicompost. In other words it is far easier to overfeed your worms than to starve them. Overfeeding is the most most currant mistake with beginners.

I don’t want to give you the impression that you must hold off from feeding for weeks on end though. After all, many people start up a worm bin specifically so they can compost some of their food waste, and/or produce worm castings for their plants (like yourself) – obviously most people want to get involved and at least see SOME progress fairly quickly.

My recommendation is to at least start slowly with the food – try a few small, easily-degraded scraps like watermelon or cantaloupe (both of which are serious worm favorites) and see how the worms respond. If they seem to be congregating around the scraps and the materials are disappearing then you can start feeding them
more.

Really, when it comes down to it, the best way to gauge how much to feed the worms is simply to observe how quickly the waste materials are being processed.

Just so you know, some signs of an overfed bin can include: bad odors, bad mite infestations, excessive growth of mold, and of course the obvious heaps of food piling up. If you suspect that you are adding too much food, your best bet is to hold off from feeding for a week or so. If need be, you can even remove some of the excess food.

As far as castings production goes, generally you should start to see them appearing almost immediately – once the worms begin to feed actively. In my experience, it takes at least a couple months before the material can be harvested and used – although this will depend on the type of system you are using as well.

Once it appears that most of the material in the bin has become dark and soil-like it is probably not a bad idea to harvest it. I will generally start up a new bin at this point, and once it has been aged for a week or so I will transfer all the unprocessed material (from the original bin) over to the new bin, then lay down a perforated sheet of plastic directly over the material in this new bin.The vermicompost from the old bin (along with most of the worms) can then be dumped directly on top. You’ll be amazed by how quickly the worms will start to migrate down into the new bin, leaving behind the compost, which you can then use as you please

Hopefully with the VermiHut Compost Bin I sale, you won’t have to play around with harvesting. Once your last tray is full, you just have to remove the bottom one. Empty it from its nice looking casting and put it back on top of your system. You are now ready to start feeding again!

.

Hope this helps!

To be totally honest, when setting up a new system I won’t even add soil or lime. In my humble opinion neither of these is really needed in a worm bed at all, and IF used, should be added rather sparingly.

Let’s start with soil.Many worm farming newcomers forget (or are unaware of) the fact that composting worms are quite a lot different from their garden-dwelling cousins. The absolute ideal habitat for a Red Wiggler for example, is in a heap of manure or a rich compost heap.

Plain garden soil on the other hand doesn’t typically have enough decaying organic matter to be able to support a decent population of these specialized worms. That being said, I do often recommend adding a small handful or two of garden soil to a new system so as to inoculate the bedding with microorganisms as well as providing some grit for the worms (helps them digest food particles).

I should also mention that ‘potting soil’ – which is typically peat moss based – could technically be used as a bedding material (to know more about peat moss please read my peat moss VS coconut post), but it would be rather expensive to use – at least in comparison to shredded cardboard or newspaper – and it may also contain inorganic fertilizer which can irritate or harm your worms.

Let’s move on to lime. Firstly, I should mention that the term ‘lime’ refers to calcium carbonate (CaCO3). Any lime mix you use should contain a high percentage of this compound – typically 95% or more. Some other names (for the same thing) you may come across include ‘Agricultural Lime’, ‘Field Lime’, or just plain old ‘Chalk’.

Dolomitic lime is different, containing 48% magnesium carbonate (and about 50% CaCO3), but should work well also. What you definitely want to avoid however is anything referred to ‘Hydrated Lime’, ‘Slaked Lime”Builder’s Lime’, or ‘Quicklime’. These are all essentially the same thing, and represent a type of lime that is quite caustic – certainly not something you want to add to your bin.

People typically add lime to worm beds in an effort to prevent acidic conditions from developing, or as a means of saving a bed that has gone ‘sour’. What’s interesting is that Red Worms actually have a very wide pH tolerance, ranging from 4 all the way up to 9 according to vermicomposting expert Kelly Slocum.

In fact, Slocum goes so far as to say they would even PREFER a pH of 5 over 7 (neutral)! It is also very important to consider the overall ecosystem in your worm bed. Rapid shifts in pH can drastically change the microbial community, potentially throwing the entire system off kilter.

Lastly, it is also important to consider nitrogen dynamics in your bed. Acidic conditions favour N-retention, whereas higher pH favours release of nitrogen in the form of ammonia gas. This can harm your worms, reduce the overall nutritional value of your bed contents, and also reduce the N content of the castings produced (thus reducing the value as a fertilizer).

All that being said, I don’t mean to imply that adding lime is ‘bad’. In fact, the additional calcium can be very beneficial for worm nutrition and overall health (it is thought to play an important role in the reproduction cycle for example).

I’m simply suggesting that it only be added in moderation – a handful here, a handful there. You may also consider using an amendment like rock dust instead of pure calcium carbonate, since it can offer a variety of other beneficial minerals apart from calcium as well.

When setting up a new worm farming system or small home bin it’s always important to keep in mind the fact that you are creating (or at least attempting to create) and ideal habitat for your worms. While these creatures are certainly forgiving compared to a lot of other ‘pets’, they do still have some important requirements – moisture, oxygen, warmth, some sort of bedding, and of course a ‘food’ source.

The absolute best way to ensure success (in my experience) is to create this ‘habitat’ well before even adding the worms. I’m not saying your system is doomed to failure if you add the worms on the same day you set up their home, but there are definitely some good reasons to hold off from doing so. That being said, I realize it is not always possible to do this – so in a next post I will chat about ways to get a worm bed up and running very quickly.

If I was setting up a big system the first thing I would do would be line the inner walls of the bin with sheets of corrugated cardboard (flattened cardboard boxes work great), and would even use multiple layers if it was going to be a cold weather bin. Aside from providing insulation, cardboard helps to absorb excess moisture, acts as a long-term food source for the worms, and will even help to slow down the decay of the bin (assuming it is made from wood).

Next I would shred up more corrugated cardboard for the bedding itself. I typically do this by hand (and yes unfortunately it can take a long time), but if you have some sort of shredder/chipper machine you may be able to do this much more quickly. The pieces
don’t need to be tiny by any means, but you don’t want big sheets of cardboard either since these can stick together and impede air and water movement.

It’s not a bad idea to mix in some other bedding materials as well if you have them available. Shredded paper (non glossy) and coconut coir can help to add more water-holding capacity, and brown leaves (preferably moist) and aged straw can provide structure while also acting as a food source.

Since we are dealing with a fairly large system here (compared to a home bin) you will likely want to spray the materials with water as you add them. For a larger outdoor system, a regular watering can (preferably with multi-stream head) works just fine.

Again, since were are not adding the worms for a little while anyway it’s not as big a deal to make sure everything is perfectly moistened. It’s also important to mention that there is no need to get hung up on exact amounts of water etc – I never use exact rules and measurements when setting up a new system, but keep the important requirements (mentioned above) in mind at all times.

Once the bin is full of partially moistened bedding I would next add a food source – typically kitchen scraps (fruit & vegetable scraps, coffee grounds etc) in my case, but if you live on a farm you may want to add some aged manure. Make sure you mix the waste materials in with the bedding as much as possible.

As far as how much to add, since we are going to let the system sit for a while (preferably 1-2 weeks) we can get away with adding a LOT of waste materials at once (and I highly recommend doing so). Again, I just ‘wing it’ most of the time and don’t follow strict rules, but if you are that type of person perhaps think in terms of a 2:1 or 3:1 bedding: waste volume ratio – and again, this is ONLY when setting up a new bin (not a typical feeding ratio once the bin is up and running). Sprinkle some more water over the top of your bin materials once everything is mixed up, then close up the system and let it age for a week or two. At some point during this aging period you can
place an order for your worms. One thing you will likely want to do during the aging period (especially with a larger system) is monitor the moisture levels in the bin. You want your bedding to be as moist as possible by the time the worms are added. If your
bin has a closed bottom you will need to be much more cautious with the amount of water added since you don’t want water pooling in the bottom of the bin.

As far as how many worms to add to a system – many recommend 1 lb of worms per square foot of bin surface area. So if your upper dimensions are 8 ft x 2 ft, you should add 16 lbs of worms, if following this guideline. I personally take a more conservative
approach – I prefer to let my worms grow into their system, so I would rather add 1/2 or even 1/4 lb per sq ft. It may take a little more time for your system to be running at full capacity, but it will cost you less initially and provide your worms with a bit more ‘breathing room’.

Hope this helps!

Worm farming secrets newsletter updated by World of Worms

Dog feces is typically rich in fecal coliform bacteria, and can contain harmful parasites as well. Cat feces is potentially even more dangerous – especially for pregnant women and small children (those younger than 5 years old). It can contain Toxoplasma gondii, a single-celled organism that can be transmitted from a pregnant mother to her unborn child, potentially leading to brain and eye disease. It can also contain Toxocara cati, a parasitic roundworm that can cause similar problems. Cats (and dogs) that are kept exclusively indoors, are not fed raw meat etc, and are taken to the vet regularly will tend to have a much lower chance of having contaminated feces, but one should still exercise caution regardless.

Bottom-line, I would NEVER recommend adding dog/cat waste to one of your main worm beds. The health risks are too great, and it won’t likely be much fun either (who wants to smell dog poop all day long?

That being said, there are still some options for dealing with these wastes with the help of your worms, rather than tossing it in your trash or leaving it on your lawn.

You can easily create a completely separate system (well removed from your main worm farming set-up) for composting pet wastes.

What I would do is dig a deep round hole (approx. 3-4 ft deep x 2 ft across), line the bottom with a nice thick layer of shredded newspaper, shredded cardboard, or coconut coir (something carbon-rich and absorbent). Again,  make sure to locate this hole a good distance away from your main worm farming area, compost heaps, gardens etc. Also make sure it is NOT located near a body of water (stream, pond etc).

You will want some sort of heavy lid over top of the hole (something a small child won’t be able to move). Even a standard black backyard composter positioned over the hole could work well (the variety that is solid plastic, not one with plastic slats and wide openings). Aside from keeping kids away, covering the waste materials will allow you to control the amount of moisture that is added.

Simply add your pet feces along with some more bedding material (any time you add feces add some bedding over top). Other materials that would work well at this point are straw and fall leaves – they are not nearly as absorbent as the materials mentioned earlier (and thus aren’t as well suited for the bottom of the pit), but they will be great for covering up any feces you add.

I definitely would NOT recommend adding the entire contents of a cat’s litter box unless you use some sort of biodegradable alternative (like newsprint pellets or wheat hull litter) – most cat litters are made of clay and you’ll just end up creating a messy clay sludge in your pit.

Adding some water periodically will be important but you definitely don’t want to go overboard, especially if you have a thick clay soil with poor drainage. Perhaps every couple times you add feces you can also add a small amount of water using a watering can.

Worms should not be added to the mix right off the bat – pet wastes will tend to give off a lot of ammonia and will not be ideal food for the worms when fresh. In fact, the best approach would be to set up two of these pits simultaneously.

Once the waste and bedding has made it about 3/4 of the way to ground level in your first you can start your second pit in exactly the same manner. After a couple weeks (without adding new feces) add a bunch of red worms to the first pit. As long as you have added enough bedding along with the feces and have kept the contents moist, conditions should be ideal for worm composting by that point.

The level of material in the first pit should decrease quite readily now that there is a population of red worms in there. Once your second pit is 3/4 full you will be able to safely add fresh feces & bedding to the first pit once again (since there will be enough of a safe habitat for the worms).

Planting ornamental trees and shrubs in the immediate vicinity of your ‘poop pits’ will allow you to take advantage of the nutritious compost you are producing. I definitely would not recommend removing the compost at any point, due to the potential health concerns I mentioned above.

Hope this helps!

Worm farming secrets newsletter updated by World of Worms

]]> http://www.worldofworms.com/will-a-worm-farm-work-to-recycle-dog-excrement/feed/ 0 http://www.worldofworms.com/techniques-you-can-use-to-help-speed-up-the-decomposition-of-added-food-materials-to-make-them-more-readily-available-for-consumption-by-your-worms/ http://www.worldofworms.com/techniques-you-can-use-to-help-speed-up-the-decomposition-of-added-food-materials-to-make-them-more-readily-available-for-consumption-by-your-worms/#comments Wed, 05 Oct 2011 22:19:34 +0000 Ludovic Bourdon http://www.worldofworms.com/?p=754 Continue reading →]]> “I am experimenting with recycled news paper sludge from work as bedding/feed. The worms seem to be happy in it, but the green food seems to take a long time to break down. Chunks of lettuce are still crisp after three weeks. Is there any way to speed up how fast food breaks down?” ~ Justin Houghtelling

Hi Justin,

One excellent tip is to freeze all food scraps in the freezer for a period of time and then allow them to thaw before adding to the worm bed.

Consider putting all scraps in plastic bags in the deep freeze for a couple of weeks and then thoroughly defrost them prior to feeding. This starts the breakdown of the cellular structure and hastens the composting process. Worms, after all, have no teeth, so their food has to be good and sloppy before they can slurp it up.

When you take the “fresh” scraps out of the freezer they are quite soft and soupy. You can pour the liquid from the plastic bags right into the bin also. Using this method the bin will remain quite moist, without adding any other liquid.

Alternatively if you don’t want to use space in your deep freeze you could mulch any large green matter (such as the lettuce leaves) before adding it to the bin. A simple food processor will do the Job and a couple of pulses are all it takes.

Breaking up the larger leaves into many small pieces in such a way allows for a greater volume of surface area to be exposed and will again speed up decomposition. You can also bury the material just under the surface of the bedding to speed the process up further still.

Of course, you could also simply break the material up by hand before adding to the bed using a basic ripping method, but the smaller the pieces of material, the faster they will decompose and become utilized by the worms…

Hope that helps!

Worm farming secrets newsletter updated by World of Worms

If you want to see how a fully set up vermicompost looks like in front of you or if you just want to talk “worms” and you don’t have anybody to do this with! Come visit me at the Organic Okanagan Festival (OOF) on Sunday September 18, 2011 from 11:00 am – 5:00 pm . My booth will be set up at the Center for Learning at Okanagan College, 1000 KLO Road, Kelowna.

Here is a link to the Festival

6th Annual 2011 Organic Okanagan Festival

Hi Kevin,

There is so much that I can talk about with this topic that I will dedicate this weeks and next weeks newsletter to your question. We will focus more on the chemical side of worm cast this week.

First of all, I have mentioned before that NPK (Nitrogen, Phosphate and Potassium) values is not important in wormcast. In fact, compared to normal fertilizers it is very low, but it does not matter. NPK value is a scientific measurement of the readily soluble forms of NPK in chemical fertilizers. These can be directly absorbed by plants once it is used in the soil. However in worm casting, the NPK are locked in the cast, and is released into
the plants slowly as micro-organisms break it down. This is much better for plants, as it takes time for plants to uptake nutrients rather than all at once.

Having said this, the NPK value in wormcast is much higher than soil, and I will explain its importance later.

Let’s start by understanding what kind of nutrients there are in soil, and how the deficiency of each particular mineral will affect plants. I will list out the minerals one by one, and explain the plant symptoms when there is a lack of this mineral. The following is taken from Virginia Tech publications on hydroponic plants:

Nitrogen – Entire plant is light green in color; lower leaves are yellow; growth is stunted.

Phosphorous – Entire plant is bluish-green, often developing a red or purplish cast; lower leaves may be yellow, drying to a greenish-brown to black color; growth may be stunted.

Potassium – Leaves have a papery appearance; dead areas along the edges of the leaves; growth is stunted.

Magnesium – Lower leaves turn yellow along the tips and margin
and between the veins; the lower leaves wilt.

Calcium – Young stems and new leaves die.

Zinc – Leaf tissue between the veins is lighter in color; yellowed; papery in appearance.

Iron – Leaf tissue appears yellow, while the veins remain green.

Copper – Leaf edges appear dark green or blue; leaf edges curl upward; young leaves permanently wilt.

Sulfur – Young leaves turn pale green, while the older leaves
remain green; plant is stunted and spindly.

Manganese – Growth is stunted; lower leaves have a checkered pattern of yellow and green.

Molybdenum – Leaves are stunted, pale green, and malformed.

Boron – Young leaves are scorched at tips and margins.

Now you can guess why worm cast is great to use in plants, because they do contain at least some of each of the minerals listed above. Of course there are some more than others, but the plants don’t use all of them in the same amounts. Take Molybdenum for example, it converts nitrate (NO3) into amino acids (building blocks for plant  protein) and it is used within the plant more than once. Too much molybdenum will be toxic to plants.

Just to give you an idea, here is an example of the percentages and composition of nutrients and minerals in vermicompost:

• Organic Carbon 20.43 – 30.31 %
• Nitrogen 1.80 – 2.05 %
• Phosphorus 1.32 – 1.93 %
• Potassium 1.28 – 1.50 %
• Carbon : Nitrogen 14-15 : 1 %
• Calcium 3.0 – 4.5 %
• Magnesium 0.4 – 0.7 %
• Sodium 0.02 – 0.30 %
• Sulphur Traces to 0.40 %
• Iron 0.3 – 0.7 %
• Zinc 0.028 – 0.036 %
• Manganese Traces to 0.40 %
• Copper 0.0027 – 0.0123 %
• Boron 0.0034 – 0.0075 %
• Aluminium Traces to 0.071 %
• Cobalt, Molybdenum Present in available form

The above is to give you an idea only, you are correct in noting that all vermicompost is different because the composition does truly depend on the type of feed you give to the worms. But from the above table you can see which kind of mineral and nutrient is more abundant within wormcast.

However I know all these figures makes no sense by themselves. So how does vermicompost compare with normal garden soil?

Other than Aluminium and Magnesium (which is about the same in both) and iron (which is less in vermicompost), the values of all the other nutrients/minerals are significantly much higher (with Nitrates up to 9 times higher) in vermicompost than garden soil.

This poses a problem in its electro-conductivity, because this is also much higher than garden soil which means there is more salts in vermicompost. When there is too much salt in soil, it sucks out water from the plant roots resulting in the ‘burning’ of plants. Although there isn’t enough salts in vermicompost to do that (it is much more common in chemical fertilizers), using too much wormcast at any one time can stunt plant growth.

It has been studied what the optimum ratio of wormcast to potting soil is. Researchers potted plants starting in different ratios of cast to soil, and found the plants with the optimum growth were planted in a cast:soil ratio of 1:4, or 75% soil. However they have shown that even 10% of wormcast shows significant difference in plant growth.

Once the percentage of wormcast is over 40%, plant growth performance is stunted and may even appear worse off than having no wormcast at all. So your use of 50% wormcast is definitely too much!

You will need to use a less amount of worm cast, and hopefully you will start to see your plants flourish!

Kenneth

c/o WormMan Newsletter http://wormman.org/?p=162