Tea production and plant growth
Via the vermiculture_owner mailing list, I saw this PDF about vermicomposting tea production and its effects on plant growth. It’s from the November 2007 edition of BioCycle. It’s an interesting read; the takeaway for me was that “aerating vermicompost tea during brewing results in significant growth responses”.
Add comment February 7, 2010
Adding redworms to a desiccating toilet system
Update 2/7/2010: Just so you know, there are some graphic pictures below. If you aren’t interested in viewing humanure, please don’t read further.
Last week I had an interesting meeting with Mike, an official at a local state park. They have a desiccating toilet that just isn’t working as well as they had hoped. Here’s a picture of the toilet system from the outside.
Eldorado Canyon State Park Bathrooms
Below is a picture of the system from the inside. They have two large plastic vaults that have air flowing from the outside into them. The feces and toilet paper are held up via a metal trough, and air flow drys them out. Wood shavings are regularly spread in the system, which is supposed to help control odor (I think). Finally, the entire mass of poop is regularly sprayed with fresh water (on a timer). That is supposed to help decomposition. (I don’t understand how the water spraying and the air drying work together, and neither did Mike.)
Eldorado Canyon Desiccating Toilet System
Below is a picture of inside the system. Yup, that’s human feces and toilet paper. I visited during the winter, and the level was not high. Mike said that the entire mass freezes solid during the winter. The white horizontal line in the middle of the picture is a tool that lets someone distribute wood chips or move poop.
Inside Eldorado Canyon Toilet Vault
The primary issue with the toilet is a high pH leachate that accumulates at the bottom of the system, below the trough. Eventually that liquid gets so high that the system needs to be pumped. You can read his description of the issues; he goes into far more detail about what has been tried. He also summarizes what we discussed and the plan moving forward:
- I’ll build a compost bin, in the basement with the vaults, loaded with worms.
- I’ll get the worms started with food scraps from the office.
- I’ll make some experimental sections in the worm bin, and try adding some of the, er, material from the devap toilets, and maybe try soaking a different section with the excess water. The idea is to see what the worms like and thrive on.
- If the wigglers like human waste, but not the bilge water, then I’ll leave the vaults unmodified, add worms, and let ‘em go to town this summer.
- If the wigglers like human waste AND the bilge water, I’ll add worms to the vaults, and scale up by periodically pumping some of the waste water up into the stack.
- Worms will crawl and explore, but they also like dark and quiet. It’s highly unlikely that they’ll crawl up to the main floor.
- If the worms are successful, they’ll probably die off every winter in the cold vaults. The warm, freestanding compost pile will have to be maintained during the winters.
- It’ll be interesting to see what happens with the odor.
- I’m totally rooting for the worms. It would be phenomenally cool if worms could thrive on the wood chips, waste, and wastewater.
It will be interesting to see how the worms adapt to a diet of human waste. I found some links that indicate that they should do alright (thanks, Google Scholar!). Here’s one on a worm composting outhouse, which discusses some of the unique aspects of vermicomposting human waste (as opposed to the more typical feedstocks of yard and kitchen waste):
The worm bin should be operated like any worm bin. The moisture, temperature and aeration needs are the same. One difference is that human waste has a Carbon to Nitrogen ratio of 20:1 and so it needs a high carbon material added to decompose best.
Here’s another article discussing using vermicomposting to stabilize sewage sludge. Here’s an article about redworms reducing pathogens (a topic I reviewed last year). This is an interesting article on how feedstock affects E. Foetida weight and length (pdf). And here’s an interesting abstract for an article on the effects of stocking density and feeding rate on biosolid vermicomposting that is worth excerpting:
Specifically, the focus of this study was to investigate and establish an optimal stocking density and an optimal feeding rate for the vermicomposting of biosolids, with paper mulch provided as bedding. A stocking density of 1.60 kg-worms/m2 (0.33 lb-worms/ft2) and a feeding rate of 1.25 kg-feed/kg-worm/day resulted in the highest bioconversion of the substrate into earthworm biomass. The best vermicompost was obtained at the same stocking density and a feeding rate of 0.75 kg-feed/kg-worm/day.
Based on reviewing these articles, a key component of this system will be adding enough carbon to keep the worms happy. The main source of carbon currently is wood shavings, but they are purchased. I think that shredded paper and/or leaves would be good alternatives. Some calculations should be made to determine how much bedding substance to add.
In addition, redworms need a pH between 5 and 9, and I believe the leachate was well above that (update 2/7/2010: per a conversation with Mike, the pH of the leachate is 8.5 or 9). I don’t think the worms will be able to process or reduce that liquid directly. However, the source of the leachate seems at first blush to be the fresh water spraying, so if the worms process the waste and help maintain humidity, less spraying may be needed, and thus less leachate may be created. Even if the same amount of spraying is required, the worm castings may retain more of the water, and reduce leachate in that manner.
I’m a huge fan of Mike’s plan to start small (with a 55 gallon drum) and see how the redworms react to waste and/or leachate. This experimentation will be cheaper and easier to control, as well as giving Mike a chance to become familiar with worm keeping.
1 comment February 2, 2010
Worms surviving the Boulder winter
I have an outdoor worm bin, and I did some things to prepare it for the winter. However, here in Boulder, we have had a pretty bad cold snap.
Here’s some weather data from the Weather Underground site for January of 2010:
You can see that we had a prolonged stretch of freezing winter. In fact, a few days ago, I went out to add some food to my worm bin, and the first whack with my post hole diggers showed that it was frozen. My worm bin is black, but it probably gets 1-2 hours of sun a day. That’s not great for winter (though it does help preserve moisture during the summer).
I dealt with this frozen worm bin a few ways:
- I added some food to the top. I had removed enough material in the fall (putting it into my garden) that I was able to just add material to the top. I made sure to cover the top with leaves and other carbon sources, and add some water (in the form of snow) to alleviate any smell.
- I froze some food. This is a fairly common wormkeeping practice, though I had never done it before. It keeps food smells down while you are storing it, and the freeze/thaw process helps break down the food faster. However, I still prefer my food scraps bucket.
- I threw some worm food away. I confess I did this in the deeps of the freeze, when I felt saving any more food would overwhelm my worm bin when I was finally able to add more food.
I have also added worms to a dirt bed in my patio area. I dug it up just a few days ago and was quite happy to see some redworms happily eating some food scraps I’d added a while ago. So, at least some of my population of worms survived the Boulder deep freeze of 2009-2010.
Add comment January 23, 2010
Sources for worm donations for community projects?
I saw a post on a worm mailing list a while ago:
I am doing a community project for my college and am starting worm composting bins at a local elementary school in Boulder. I am trying to get a hold of enough worms for 4 bins, about 2 feet x 1 foot (10 gallons). Does anyone know where I can get a hold of enough worms for this project, and possibly as a donation to the school?
What to do? Of course, she could buy the red worms from a local source, but she’s trying to do this for a school on a shoestring budget. I thought the following options would be the best way to acquire several pounds of worms for a community project around Boulder, Colorado.
- Contact local Colorado producers and see if they can give you a great deal, or perhaps donate them. I don’t know any big producers in Boulder. Boulder Compost Company used to do this, but they shut down a bit ago. You could try contacting them and seeing if they know anyone else around here.
- Another alternative would calling Growing Gardens and seeing if they can spare some worms. I know they have a largish bin; not sure how many surplus worms they have.
- I’d also contact Flatirons Elementary School here in Boulder. It looks like they have some kind of worm bin program [pdf] and might be willing to share.
- And, finally, it would be worth contacting Eco-cycle. They do worm composting and might have some extra for donation.
So, the general path I’d recommend if you need pounds of worms for a non profit would be:
- Try worm farmers for discount/donation
- Find other organizations that have worms (community gardens, recycling centers, schools) and see what they did and if they have any to spare
- Pay for some worms and start the project on a smaller basis than you may have wanted
What would you recommend?
PS She ended up getting a donation from a woman in Loveland for all her needs.
Add comment January 13, 2010
Redworm composting…in a 2L bottle
Ran across an interesting book called Bottle Biology (apparently funded by the NSF).
Google books has a preview online, and there are two pages devoted to creating a worm bin in a 2L plastic bottle. They tell you just enough to whet your appetite, though:
Worms play a major role in breaking down plant matter and creating fertile soil. Earthworms eat fallen leaves and other plant parts. Their droppings, or “castings,” fertilize the soil. … Observe wonderful worm activity yourself by building a worm column.
Add comment January 3, 2010
Introduction to Worm Composting Class in Denver
The Denver Urban Homesteading Center is hosting vermicomposting classes.
From that page:
Worm composting, a.k.a. Vermicomposting, uses worms to break down shredded paper and food scraps to turn it into what is commonly called “black gold”: a very valuable soil amendment that provides the healthiest plants around.
Students will learn how to set up and maintain a home worm bin. Bedding, bin type, feeding, moisture levels, maintenance, harvesting and how to use the compost are all covered in this informative and FUN class!
Check out the calendar for a class time that works for you.
Add comment December 24, 2009
Discussion on winter worm composting
I’ve already published some of my thoughts on the topic of winter worm composting, but here’s an interesting discussion of the same on vermicomposters.com.
If you’re a wormkeeper and aren’t part of vermicomposters.com, it’s worth a look. It’s a social network for worm composters.
Add comment December 21, 2009
Holiday worms?
This article, from Boulder Organic, mentions giving worms for the holidays:
Downing says ellie’s also carries worm-composting bins that are about 14 inches square and two feet high. They range from $75 to $85.
The worms must be purchased separately, she says, but you can complement the gift with a copy of the book Worms Eat My Garbage by Mary Appelhof for $12.95.
This seems like an alright idea, but for maximum success of a worm bin, I feel it’d be better to wait until spring to give this gift. Then it’s more likely to have a happy place in a ‘in-between space’ like a garage or a basement. Also, one won’t be as tempted to overfeed it, since there’ll be a compost pile for organic waste (or at least, the weather will be better for creating one).
What do you think?
Add comment December 16, 2009
Worm bins for offices
I thought this exchange, on the Fort Collins worm exchange list, was enlightening, so I thought I’d post it here with comments.
Aaron Orechwa asks:
Hi I am in charge of implementing a compost program here at our office in Fort Collins, CO. Our office consists of approximately 35 people, and I thought it may be a good idea to start a composting system to divert daily organic waste into our solid waste stream. Right now I am looking into a green cone system for food waste and a rotating barrel system for yard waste as well.
Given the current climate and weather conditions, is worm composting a good idea? We will have to place the compost outside because of corporate policy difficulty in having an indoor system. Let me know if you can help or suggest any better ideas. Thanks
John Anderson answers:
Corporate policies of externalizing costs have gotten us in this environmental perdicament to start with so that needs to no longer be an acceptable practice. Worm composting can be done outdoors effectively. . What do you suppose they did with out us for 6 hundred million years? Systems can be designed to fit your resource output and our weather extremes with no on going carbon footprint. To size the system you must first need to know volume of the resource by weight on a daily, weekly, and monthly basis. Hope that helps.
See me at cowormman.com for further info. The intent of this exchange is for community households with or without composting worms to get connected and exchange their resources. Talk to you soon about possibilities?
John A. www.cowormman. com
I was unable to find sizing information on John’s website, but a bit of googling turned up this:
Making some wild assumptions about Aaron’s situation, lets assume that we can get away with 1/3 sqft/person, because each person only eats lunch at the office (1/3 of their meals), and 1/2 the time folks eat out. Therefore 2sqft/person*1/2*1/3 = 1/3sqft/person. (Of course, the best way to estimate size would be to measure discarded organic waste first.) 35*1/3 equals approximately 12 sqft of worm bin. That’s only 2×6, which is probably a fine configuration.
Other considerations:
- having the worm bin outside: eminently possible here in Colorado. Just make sure the worms can escape into the ground and insulate. You can see pictures of John’s worm windrows here, and they definitely survive the Fort Collins winters.
- overfeeding: as Melanie Nehls Burow warns, “[b]etter to underfeed than to overfeed in general.” It’s easy to get enthusiastic and overfeed your worms, especially if you didn’t put enough in the system to start with.
- underfeeding: especially in winter, how is feeding going to happen? This is obviously a key issue, and should be resolved at the beginning
- what to do with resulting vermicompost: you’ll have a lot from a bin this size. Give it to employees? Give it to the landscaping company? Advertise it on craigslist/freecycle? What you definitely don’t want is to end up throwing it away.
- general maintenance: replacing bedding, removing castings and/or vermicompost, watering bin when dry. These are all tasks that need to be done on a semi regular basis.
I think, in general, worm composting for office situations is better than traditional composting. No work to turn it, capable of processing large amounts of food wastes (which I imagine are the typical wastes from a typical office), and relatively low cost.
Add comment December 15, 2009
Orange peels in worm bins?
I like to put all my organic waste in my worm bin. However, during the winter, I like to load up on citrus, and in particular orange peels. In “Worms Eat My Garbage”, Mary Appelhof says that orange peels can be put in worm bins. I have often put peels in my bin, but a few years ago, I overloaded a bin with too many peels.
So, what to do with orange peels, especially large amounts of them (mmm, clementines!)?
Recently, a discussion thread on this very subject occurred on the_worm_bin. sesealrcd said orange peels “are very anti bacterial”. I looked for any evidence of that, and found some references on alternative medicine websites, but nothing I would consider conclusive. From personal experience, I have seen orange peels take longer to rot than other foods.
Nan just “cut[s] them up fine then just throw[s] them on top and they break down into the soil” near her roses. Connie adds them to some big bins with lots of other food, and doesn’t put them in very often–every 10 days or so. Students in Davis CA also put orange peels in their worm bins. Sherry chops up her rinds in a food processor and adds them as well.
If you don’t want to put peels in your worm bin, Rob suggested killing ants by “soaking pieces of peel in a recycled gallon jug then drench the ant hill.” I found a page referencing an experiment with citrus oils and fire ants, in which “[i]n most trials, the level of activity in mounds receiving citrus oil alternatives was statistically comparable to conventional diazinon formulations”. I also have personally just saved dried orange peels and given them to a friend who used them to make soap and potpourri.
As always, experiment. There are a number of other ways to use peels, and it looks like adding some to your bin, and then monitoring worm health, is a viable option.
1 comment December 4, 2009
