low-energy in-house carbon sources for humanure

I'm looking for options to the use of sawdust as carbon source in a dry compost loo.  For the moment, I'm considering the Jenkins' bucket system, as it has a simple and easy to clean infrastructure.  For it to work properly, though, the particle size of the carbon source should be very small, to make it immediately accessible to the microorganisms involved (and thus the common use of sawdust). However, there is no on-site wood mill, and I don't want to design a system that needs a continuous import of resources. The main carbon sources easily avaiable on site are leaves and leaf mould, reeds and grasses, both of which can be easily dried (and are more often than not harvested dry). Rotting wood is also available, and there's the sporadic bout of woodCHIP.

According to Joe Jenkins, straw is good as a cover for the compost pile, but no good in the bucket, as particle size is too large. Dry leaves are often mentioned as an alternative, but they also have a large particle size.  However, I can imagine that the leaves of most temperate deciduous trees in Europe decompose much quicker than straw, and might even break down to rather small particles in the process of storage.

I'd like to know if anyone here has experience with these carbon sources for humanure, and / or producing "straw-dust" or "leaf-dust" without the need of electric devices.  I've seen the mesh-bucket used for rotting wood, but that wouldn't work for grasses.

Any other potential sources of carbon?  Please no paper... not even toilet paper!


Thanks in advance!

Hi Dita, welcome to Permies. Excellent question and the Jenkins system is a great method that I have been using for four years now. While the fine sawdust is preferred because it breaks down much faster, the leaves will work splendidly. Dry leaves will crumble rapidly when hand shredded, something you can do as necessary after using the loo. It will make awesome compost. Also if you are in a pinch, soil can be used as a cover material as long as you are still getting a carbon input within the collection pile. reeds may be too big like straw, but mowed or scythed grass will work well too.

Use whatever you have on hand, the microbes won't care, and try to keep a surplus of leaves stocked up. Good luck!

If it's just you/family, i.e people who can be trusted, why not harvest a bunch of reeds or if they are too coarse then straw, and have a heavy duty pair of scissors by the toilet, spend the time on the thrown chopping up your needs.

Welcome Dita! Are you in the process of setting up your homestead? If so, could you consider specifically planting a grouping of fine/small leaved shrubs and trees (I'm thinking like blueberries - they're hard to grow but just to give you the idea) that would allow you to collect a few bags of small leaves in the fall to keep for the purpose?  I've been thinking of a similar system for myself. The leaves in my eco-system are frequently *very* large, and we get a lot of dew and rain in the late fall when they drop, so getting dry leaves is an issue. It's harder to store wet leaves.

Thanks for your warm welcome and your prompt replies!

Daniel Ray wrote:Hi Dita, welcome to Permies. Excellent question and the Jenkins system is a great method that I have been using for four years now. While the fine sawdust is preferred because it breaks down much faster, the leaves will work splendidly.

Great to read that, Daniel, thanks!  That was my intuition, but I much rather get the opinion of someone with experience to back that gut feeling up.


I also like your ideas of using the loo-time for preparing the carbon source...

Daniel Ray wrote: Dry leaves will crumble rapidly when hand shredded, something you can do as necessary after using the loo.

Skandi Rogers wrote:If it's just you/family, i.e people who can be trusted, why not harvest a bunch of reeds or if they are too coarse then straw, and have a heavy duty pair of scissors by the toilet, spend the time on the thrown chopping up your needs.

And the diversity...

Daniel Ray wrote:  It will make awesome compost. Also if you are in a pinch, soil can be used as a cover material as long as you are still getting a carbon input within the collection pile. reeds may be too big like straw, but mowed or scythed grass will work well too.

Is the grass scythed dry or dried?  Or does it work (in the bucket) even if you add them green or greenish?

Daniel Ray wrote: Use whatever you have on hand, the microbes won't care, and try to keep a surplus of leaves stocked up. Good luck!

Thanks! It sounds like a rather resilient system.  Joe Jenkins speaks so often of people doing it wrong, that, well, it feels a bit daunting.

Thank you, Jay.

It's a great idea to plant the carbon source.
I'm helping with setting up homesteads, but myself, I'm still more or less nomadic.  I'm trying to test this system and bring it along, spread the compost, so to speak.

Jay Angler wrote:Welcome Dita! Are you in the process of setting up your homestead? If so, could you consider specifically planting a grouping of fine/small leaved shrubs and trees (I'm thinking like blueberries - they're hard to grow but just to give you the idea) that would allow you to collect a few bags of small leaves in the fall to keep for the purpose?  I've been thinking of a similar system for myself. The leaves in my eco-system are frequently *very* large, and we get a lot of dew and rain in the late fall when they drop, so getting dry leaves is an issue. It's harder to store wet leaves.

I think decomposition rate is more important than leaf size.  In my experience, blueberry is not such a good choice, as in most species and varieties the leaves tend to be tough and leathery, sometimes even waxy.  They take quite some time to decompose and break into small particles.  Also, not sure how easy they would be to harvest.

There are some studies on leaf decomposition rates out there. From what I have seen myself, hazel, lime (linden), poplar, horse chestnut, most maples, birches,  all make rather crumbly leaves.  Beech leaves seem to take quite some time to decompose, but dry easily and do crumble quite nicely. Same with sweet chestnut (not many around here--"here" being Northern Poland right now). Oak leaves are tougher (and I preferentially use them as mulch for lettuces).

Dry conifer needles might be good.  They lose their acidity rather quickly when rained on, or during the drying process. They do not crumble so much, but they might be small enough.

Also, leaf mould would probably be a great carbon source, since it already has lots of fungi growing.  Perhaps the wet leaves would be an asset?

I've also been thinking of a wet black-water management system, which might work better in wet environments (such as Devon, where I'm more or less "home").  But I love the idea of making our own compost.  Manure often has to be brought  in, so it woud make sense to make our own.

What about you?  Are you homesteading?  Do you have an in-house "waste" management?

Dita, people do end up making composting mistakes with a humanure system sometimes. Usually this stems from not enough cover material or property bulky material on the collection pile which leads to smell and/or flies getting to the pile. Another easy mistake is not taking the time to add a fresh bucket of compostable materials in the correct manner. Joe outlines it well in the book, but he does have a series of youtube videos that demonstrate the proper technique.

Dita Vizoso wrote:

There are some studies on leaf decomposition rates out there. From what I have seen myself, hazel, lime (linden), poplar, horse chestnut, most maples, birches,  all make rather crumbly leaves.  Beech leaves seem to take quite some time to decompose, but dry easily and do crumble quite nicely. Same with sweet chestnut (not many around here--"here" being Northern Poland right now).

I will have to go hunting for those studies. My example of blueberry was just the size aspect and a quick google search wasn't helping me. There are people here who can grow the Japanese maple and the difference between its leaf size and our local "Bigleaf Maple" (Acer macrophyllum) (https://en.wikipedia.org/wiki/Acer_macrophyllum) is impressive. The Bigleaf maple leaves tend to just mat down in compost and when I've used them to mulch the duck run. I've been contemplating this issue for some time as our environment is very damp in the winter, so drying things and keeping them that way is a challenge. We currently use a lot of shredded dead tree, but that takes diesel, equipment, time, and a big mess so I've been looking for plants that will do double duty.

Hi Jay

Jay Angler wrote: I will have to go hunting for those studies. My example of blueberry was just the size aspect and a quick google search wasn't helping me.

These are some I found interestingé

https://www.britishecologicalsociety.org/100papers/100_Ecological_Papers/100_Influential_Papers_042.pdf
https://www.ncrs.fs.fed.us/pubs/jrnl/2008/nrs_2008_karberg_002.pdf
https://sciencetrends.com/exploring-leaf-and-litter-traits-in-decomposition/

This review has a hefty bibliography on the subject:
https://academic.oup.com/jpe/article/1/2/85/989869#104900843

Jay Angler wrote: There are people here who can grow the Japanese maple and the difference between its leaf size and our local "Bigleaf Maple" (Acer macrophyllum) (https://en.wikipedia.org/wiki/Acer_macrophyllum) is impressive. The Bigleaf maple leaves tend to just mat down in compost and when I've used them to mulch the duck run. I've been contemplating this issue for some time as our environment is very damp in the winter, so drying things and keeping them that way is a challenge. We currently use a lot of shredded dead tree, but that takes diesel, equipment, time, and a big mess so I've been looking for plants that will do double duty.

I hear you.  I'm really fed up with using machinery and energy for such things.  I guess you've tried piling and covering the leaves?.  That has worked for me in Devon (avg monthly precipitation around 90mm in winter, but temps seldom lower than -5 C, rel. humidity around 90%), and near Basel (from 70 to 90 mm, average low temp also -5 C), they do not get entirely dry, but dry enough to crumble. Even in outdoor piles. I've seen that often in many different places, much colder ones as well (but possibly not as damp), and it worked quite well in the very humid tropics (but there it just got decomposed quicker). Perhaps it's the leaf composition, as well?  We make leaf piles (often kept in place with either pallets or chicken fence), exposed to the elements. For drying quickly we also made piles in boxes and brought them in.  Joe Jenkins suggests having a bay for dry carbon source by the compost piles, his only has three airy walls and a roof (with water collection... dreamy sigh..) over it.

For "natural hay", I cut grasses that have been left to grow the last bit of summer, and has dried on site.  I do that on a rainless period, and bring them in.  They've kept dry so far, but I guess I've been lucky with the weather. Perhaps if you mix the leaves with something coarser, to keep them aereated, they might turn into nice humus, which could work for the paths (although it would feel like a waste of great composting or mulching material to me).  I'm going to try leaf humus for the humanure buckets.  As I'll be lucky enough to have relatively isolated quarters for three months, and plenty of leaf litter to try, it looks like an opportunity not to be missed!

Daniel Ray wrote:Dita, people do end up making composting mistakes with a humanure system sometimes. Usually this stems from not enough cover material or property bulky material on the collection pile which leads to smell and/or flies getting to the pile. Another easy mistake is not taking the time to add a fresh bucket of compostable materials in the correct manner. Joe outlines it well in the book, but he does have a series of youtube videos that demonstrate the proper technique.

Thanks!  Also for the accounts of your experience.  Now still looking for larger-scale hand-shredding ideas for grassy materials...

Dita if you feel you're in a position to do some research on this, that would be awesome!
1. For example, we used to use commercial wood shavings in our brooder (my husband raises a batch of Cornish Cross once or twice/year and they start in a brooder before moving onto grass). I find these shavings take *forever* (like easily 3-4 years) to decompose. They are difficult to get evenly moist when trying to compost them, so decomposition is also inconsistent within the pile.
2. This year I switched to using only organic coffee sacks, made from a variety of plant fibers. I layered the poopy sacks in a pile with some partially composted woody debris in layers and I watered them as I went. It will be interesting to see how well they decompose.
3. A couple of years ago, I set myself up a humanure bucket with an old toilet seat for earthquake preparedness (I've got no good place for it at this time for regular use, unfortunately). I decided to try biochar in it, thinking this would act to charge the biochar with nitrogen (women just don't have the best plumbing for the "water the tree method") and for its short test period there was no stink. Biochar may be something that would be easy for you to make and test, but be wary of the dust affecting your lungs.

Whatever materials you try in your bucket, I'd love to hear how they work. Paul Wheaton often makes up little charts comparing approaches based on things like cost, availability, ease of use, effectiveness etc, and I find the approach helpful.  

                                                                                                                                               

Jay Angler wrote:Dita if you feel you're in a position to do some research on this, that would be awesome!

Indeed!  Not sure I'll manage to do research as in comparing different carbon sources (unless I severely up my eating game)... perhaps I'll get some other people on board.  But I do suffer from that write-everything-down-and-make-stats disease.  Won't get stats, but will certainly get like a "pilot experiment".

Jay Angler wrote:
1. For example, we used to use commercial wood shavings in our brooder (my husband raises a batch of Cornish Cross once or twice/year and they start in a brooder before moving onto grass). I find these shavings take *forever* (like easily 3-4 years) to decompose. They are difficult to get evenly moist when trying to compost them, so decomposition is also inconsistent within the pile.

I wonder if that might also come from a mixture of different woods?  I set up a garden here in Poland.  With the advent of pellet stoves, which are becoming very popular hereabouts, there's no free stuff anymore from the mills, but, as we're surrounded by timber forests, we do find the odd pile of wood chip.  That went almost exclusively as moisture-retaining mulch on our swales/paths. They're holding on quite well, despite the continuous trodding, the heavy fungus load, and the extreme weather. Yeah, wood chips do take forever to decompose.Which is great, in this case!  Our swales/paths are placed so that whatever moisture and nutrients leak from the wood (and whatever else gets accumulated) go straight into the beds... anyhow.  Far from humanure, sorry!

Jay Angler wrote:
2. This year I switched to using only organic coffee sacks, made from a variety of plant fibers. I layered the poopy sacks in a pile with some partially composted woody debris in layers and I watered them as I went. It will be interesting to see how well they decompose.

Sounds great!  Are you sharing this in another thread?  I'd love to follow that.

Jay Angler wrote:
3. A couple of years ago, I set myself up a humanure bucket with an old toilet seat for earthquake preparedness (I've got no good place for it at this time for regular use, unfortunately). I decided to try biochar in it, thinking this would act to charge the biochar with nitrogen (women just don't have the best plumbing for the "water the tree method") and for its short test period there was no stink. Biochar may be something that would be easy for you to make and test, but be wary of the dust affecting your lungs.

We get some char from the wood stove, and I just started separating it from ash... Haven't explicitely made char yet (it's in my bucket list--pun intended), but it would indeed make sense for the humanure.  I'll see how easy it is compared to using leaves. Great to know that it works well in the bucket.  I've thought of using ash.  The soils both here and in Devon (where I'll be starting the humanure) are very acidic, so it could be not a bad thing.  I'm worried about the composting, but perhaps mixing in some soil with the ash could work.

Thanks a lot for your input and ideas!  Can't wait to start!

One of the things I love about Permies is that people put out different ideas and experiences, and sometimes that gives me better ideas for coping with an immediate problem.
1. Sawdust is small so it soaks up moisture well and decomposes quickly. Wood shavings, not so much.
2. Sawdust tends to pack down when I try to mulch with it.  Wood shavings not so much.
My ecosystem tends to only get snow every 3rd winter, but about every 5th winter we get a significant dump over a short period. This is that year! We've had in the order of 58 cm (>20 inches) in 5 days and our portable chicken shelters don't have snow tires. Shelters that would normally move every day or so are stuck and getting desperate. This morning I took a 68 liter bin, layered commercial animal shavings with sawdust from our wood cutting shed, mixed it as I went, and started spreading it in the chicken and duck shelters. This is a lot of work, so not something I'd plan on doing routinely, but if it gets us through the current crisis, I'm OK with that. In fact, I'm off to do more of it, and more snow shoveling. Thanks all you smart and observant permies!

Skandi Rogers wrote:

why not harvest a bunch of reeds or if they are too coarse then straw, and have a heavy duty pair of scissors by the toilet, spend the time on the thrown chopping up your needs.

My problem has always been how to chop things up efficiently. Although the right kind of scissors will work, they will tend to add dust and bits to your indoor environment. A permies thread I was reading today had a link to this video: https://youtu.be/qzqJS_EJV94  and at the ~15 minute mark, they show a prototype for a bike-powered straw chopper. Maybe that needs to go on my bucket list. (the permies thread was:https://permies.com/t/7535/manual-flour-mill-attached-stationary

I screen my compost. It seems the compost that passes 1/2 mesh, but not 1/4 mesh would be perfect.  So screening partially composted carbon sources might work.

Jay Angler wrote:Skandi Rogers wrote:

why not harvest a bunch of reeds or if they are too coarse then straw, and have a heavy duty pair of scissors by the toilet, spend the time on the thrown chopping up your needs.

My problem has always been how to chop things up efficiently. Although the right kind of scissors will work, they will tend to add dust and bits to your indoor environment. A permies thread I was reading today had a link to this video: https://youtu.be/qzqJS_EJV94  and at the ~15 minute mark, they show a prototype for a bike-powered straw chopper. Maybe that needs to go on my bucket list. (the permies thread was:https://permies.com/t/7535/manual-flour-mill-attached-stationary

Thak you, Jay, I love the video.  That's what I'm looking for indeed.

Just found this thread and have been wondering about the same issues, as I started using a Jenkins-inspired system last Fall. Have tried medium-small leaves, but the problem of Fall moisture in the Seattle area does make them a bit stinky, not to mention buggy. Just couldn't get them dry enough outside in Fall, even under cover, although they were better than nothing. Tried also fairly dry fallen needles that I had gathered in summer from my Hemlock tree. Those were pretty stinky, too, when they were "moistened" in my bucket loo. Ash from the fireplace has been the best so far in terms of odor, but it's kind of impossible to avoid breathing in some of the dust as I sprinkle it on, plus I generate ash only seasonally. Have also tried sawdust generated by moistening fireplace pellets--admittedly a commercial solution--and it works OK with the odor but not as well as the ash. Recently kept some self-generated sawdust from sawing up some fallen tree limbs due to recent snows. That sawdust sat in sun for a while and was pretty dry, and worked well. Coffee grounds--even moist ones-- work well too for loo odor, but it takes at least a few day to generate enough of them in my family to cover even one solid-waste "event". I should try saving grass clippings from mowings this summer, as some posters suggest, as well as just digging some soil (after it's dried out a bit here).

Overall, I've learned that you can use a variety of what's available, and that some things work better than others. I really like the idea of just digging soil out of the yard and trying it for loo cover material, because when my compost piles have matured, I'm going to need some gaps in the yard to put the compost in!

BTW I came across this youtube vid (https://www.youtube.com/watch?v=bUzTVs8iDPE) that shows an "ash flush toilet" from perhaps 50+ years ago. It's basically just a hopper for ash that might have very conveniently covered your business in its heyday. Might have worked with sawdust too. Seems like basically a large "bulk bin" type hopper mechanism, like those in some supermarkets that deliver bulk flours into plastic bags, except with a pull chain to dispense it.