Largescale Manure Vermicomposting
Horse manure (with bedding) pile – prime time Red Worm real estate!
Here is a question from Brent:
I was wondering if you had any info on system design for
composting horse manure? We usually have 3-4 horses on site and I am
currently composting teh manure/shavings mixture. The process take a
few months and I suspect the worms would be faster and more efficient.
Let me kow if you know where I can get info on larger systems and
managing these to take care of my manure. Thanks!
Great question! I’m certainly not a ‘design guy’ by any means, but I do have some thoughts to share on this topic. For starters, let me say that you are absolutely right – adding composting worms to a manure composting system should GREATLY speed up the process. I know I am a tad biased here, but I would also say that it will result in a vastly superior product as well – and technically TWO products, if you count all the worms you’ll be growing!
I would never suggest that you completely skip the ‘regular composting’ stage however – in fact, when you are working on a large scale with manure, implementing some sort of ‘pre-composting’ stage will be really important. It will help to rid the material of weed seeds and pathogens (research has shown that vermicomposting effectively removes pathogens as well – but never hurts to be extra sure!), and will also remove a lot of the heating potential and excess ammonia, both of which can lead to dead worms in a hurry!
There are multiple approaches you can take as far as the design of your system goes – what it comes down to is asking yourself how seriously you want to get into this? If you have plans to sell the worm castings (vermicompost), then perhaps you will want to invest some serious money in a fancy continuous flow system (more on that in a minute). On the other end of the scale, if you simply want to reduce the volume of manure on site, then maybe you will be ok with some very basic approach.
On the basic end, you could literally just pile up the manure, let it sit (and heat up) for a period of time then add composting worms to it. Some of the most incredibly successful populations of Red Worms I have ever seen have been living in old manure heaps. The downside of this approach is that it doesn’t really offer you a good way to separate out the worm compost – especially if you are continuing to pile up more fresh manure on it.
Another low-tech approach which can be VERY effective is what’s known as the “wedge” system. In essence, I am talking here about a ‘souped up’ manure pile that is then simply extended into a windrow (or multiple windrows). If you have the space for this and don’t feel like spending big bucks on an actual system, this is definitely the route I would recommend taking!
In a nutshell, you would start with a relatively small pile (or piles) of manure – material that has already been ‘precomposted’ for a week or so – and add to it a few pounds of Red Worms (Eisenia fetida). Let the worms work this material for another week, then start adding new material to one end of the heap. Over time you will end up with windrows, and the beauty of this approach is that the worms are going to follow the end with the newest (highest quality) food material. Eventually (exact time will depend on how quickly you are extending the windrow), the material back where you started will be nice worm compost, with relatively few worms and cocoons – obviously, the longer you make the windrow the more mature this material will be.
If you are planning to market the finished compost, you may want to do this indoors, or at least under some sort of canopy to help prevent rainfall from removing some of the potency of your castings. The size of the windrows would be up to you – it is important that they are manageable however. Perhaps 3-4 feet in width and about 3 feet in height (length would simply depend on the amount of room you have).
Moving on to a more ‘high-tech’ approach…
If you DO have the dollars and the desire, you may want to go all-out with this and do something similar to the guys at Worm Power. In other words, build (or have someone build for you) some type of continuous-flow vermicomposting system. Here are a couple of interesting YouTube videos about Worm Power to give you a bit better idea of what I’m talking about:
I suspect that given the details you provided me with regarding your current situation, this approach might be a bit more than you would be interested in, but it’s always good to know what possibilities are out there!
Anyway – I hope this helps, Brent! The bottom-line is that I definitely recommend you get into vermicomposting, since you have access to a material that Red Worms absolutely love. Not only will they help you to reduce the volume of your manure, but you will end up with an abundance of top notch ‘compost’ (although I hesitate to even call it that), along with countless worms that can be sold or used in other worm composting systems.