Leaves and forest duff in lieu of shavings

I don't want to purchase wood shavings for composting toilet, so I'd like to know if leaves and forest duff, of which I have plenty, is a good substitute.  Is there a particular reason people use shavings, or is it just convenience and aesthetics?  Are leaves not sufficiently absorbent?

Thanks for any insight.

Tyler,

I don’t have any specific authoritative knowledge, but I suspect that forest duff could work just fine.  If I were using leaves, I think I would want them shredded up as much as possible.  You could use a lawn mower or a little leave blower/vac.  Personally I have a Worx ac blower vac that I have used for blowing and then shredding leaves.  I also bought a little hose extension that connects to a little canvas open ended bag that lets me collect the leaves in a 30 gallon garbage can which is handy for gathering a larger bulk of leaves.

Maybe, potentially, the leaves might not be as absorbent as the wood shreddings, but then I suspect that you would just have to change the leaves a bit more often.  I personally see no reason that this would not work.

I say give it a try!

Eric

Tyler,

I am giving this some more thought.  Some substances ABSORB water, meaning they bring water into themselves like a sponge.  Some substances ADSORB water, meaning the water sticks to the outside surfaces but never becomes locked within.  Think of something like wet sand.  Hopefully I got these two concepts accurately described.  Perhaps RedHawk could offer some of his expert commentary.

Plausibly shredded leaves would adsorb water.  This doesn’t mean they won’t work, only that they might not suck up as much water and need replacing more often.  

Again, still might work just fine, and I still say give it a whirl.

Eric

I don't use a composting toilet, so I can't speak from experience, but I have used the needles/duff from under the Eastern Red Cedar trees in the catch pans under the rabbit cages & found it helped absorb the liquid and kept the smell down. Also, I would break up the dropped sticks & pick up the bark shreds they tend to shed, and the excess nitrogen would really accelerate the process of breaking it down.
So that may provide a purpose for any of the ERCs you haven't removed yet.

I have found that whole leaves (particularly our Big Leaf Maples) tend to compact adn get slippery if used in our chicken or duck pens, which supports what Eric Hanson said about them *adsorbing* water. I think that shavings have lots of rough surface area, whereas the leaves are smoother. If it's mixed with pine needles, that seems to help.

That said, Tyler identifies that she has lots of it, so if it were me, I'd go ahead and use it generously and let my nose be the judge. The benefit of forest duff is that it likely will come with lots of helpful micro-organisms already attached to speed the decomposing process along.

If you use the leaves whole the flat surfaces will stick together and clump badly.  If the leaves are broken up they don't stick together so badly.  I think the key is that wood shavings absorb water quite readily while whole leaves tend to she water.  My observation is that even when leaves stick together with a lot of moisture between them, there isn't much moisture in the leaves unless they have been down and are breaking down.  You might be ok with forest duff since it is made of leaves that are pretty far along in the process of decay, but stay away from freshly raked leaves, even if they are broken up by some method.

Either way, I'd give it a shot.  If it worked, then I would keep doing it.  If it didn't, then try something else.  Just my .03 worth.

Tyler Ludens wrote:I don't want to purchase wood shavings for composting toilet, so I'd like to know if leaves and forest duff, of which I have plenty, is a good substitute.  Is there a particular reason people use shavings, or is it just convenience and aesthetics?  Are leaves not sufficiently absorbent?

Thanks for any insight.

I tried using forest duff and old crumbly tree stumps in our composting toilet for a few months. Not good. We had so many flies and spiders and other creepy crawlies in our bathroom, and it didn't smell good.  Once we switched to wood shavings or sawdust, the smell, the flies, all went away.  We can still get ours free. You might want to put the word out in your community that you are looking for wood shavings or sawdust. We get ours from a friend who does a lot of woodworking. Hope you can find some too. They work great!

I have done Humanure for a few years.  My present situation doesn't give me opportunity for that.  The way I did it was use mowed up Autumn leaves (and grass clippings that came with it).  I used it from my own yard and neighbor who had his tractor set up for it.  I figured that if he was going to do that anyway, that I might as well put it to good use.  

What I did was store the pile next to my compost pile.  I covered it to keep it (somewhat) dry.  So, when I emptied my bucket, I just refilled my coverings (mowed leaves) at the same time.  So, I went out with a poo filed bucket and empty coverings bucket, and came back in with an empty poo bucket and full coverings bucket.  In winter, I think I went out with some water in the coverings bucket to wash the poo bucket a little.  

It is amazing how much heat that pile produced for so long.  Often times there would be over a 100 degree differential with the outside air.

I miss doing it.  But, I definitely needed to optimize it better.  

In my opinion, chopping up the leaves and letting them dry out is is optimal, ...more surface area.  Sometimes in Summer there were a few more buggs, but I think if I changed out the buckets more often that would have not been a problem.  Like I said, it needed just a little more tweeking, and there wasn't enough annoyance to push me to more innovation.  

Leaves by themselves will not provide your pile with the right structure to let enough air in. It will get anaerobic unless you put a bunch of aeration tubes in it. You will need at least half of your carbon material to be either shavings or wood chips or hay or straw. Something to fluff it up.

Like others have said, whole leaves don't seem ideal. Things I have had moderate success with at various times do include nice forest soil though. Also partly composted chicken manure and rice hulls (although I realize that could be another purchase).
Also worth making sure you can't get sawdust free. Do you all have any woodworkers, cabinet makers, saw mills in town? Anyone who cuts a lot of wood is already collecting a lot of sawdust and they're usually happy to give it away

Sawmills and woodworkers are also usually a good source of very reasonably priced shavings because they are planing boards constantly. I think shavings have the best structure of all the carbon sources

carl gibson wrote:Sawmills and woodworkers are also usually a good source of very reasonably priced shavings because they are planing boards constantly. I think shavings have the best structure of all the carbon sources

I realize my experience is with ducks, but I have winter housing for a group and we have *very* wet winters. Sawdust may in theory decompose faster than shavings, but I find I can only use it in very thin sprinkles or it mats into an impermeable layer. Chipped and shredded tree duff, even if it's already wet from the rain when it goes in, does appear to help with the "structure" as carl gibson observed. I realize ducks and humans aren't direct analogies as the duck equivalent of urine is more solid and comes out with the equivalent of feces, but the effect is close enough if you're using a bucket system.

Also "sawdust" can vary a lot based on how sharp the saw blade is-a fine powder that doesn't allow air in is due to a dull blade, while a sharp blade will produce much better results. Joe I believe mentioned that he gets a truck load dropped in his yard once a year and it sits out, and that a damp material makes a better cover for use inside. I used sifted mulch and if it was totally dry it's a bit hydrophobic, so I would leave the material outside for morning dew and would spray a little water on to help with dust too.

I've used thatch (dead grasses) in my humanure bucket and, while it wasn't as good as sawdust or shavings, it worked pretty well.

Tyler Ludens wrote:I don't want to purchase wood shavings for composting toilet, so I'd like to know if leaves and forest duff, of which I have plenty, is a good substitute.  Is there a particular reason people use shavings, or is it just convenience and aesthetics?  Are leaves not sufficiently absorbent?

Thanks for any insight.

Tyler,

Shavings is one of the least desirable cover materials in a compost toilet (not "composting" toilet). Leaves and forest duff are much better. Shavings have wood particles that are too big and too dry. They also allow air to pass through them, including odor. Yes, they work in big municipal piles, but if you're doing backyard composting and all you have is wood shavings for cover material in your toilet, pile the shavings outside where they can get wet from rain and let them rot before using them.

Here's an excerpt from the 4th edition of the Humanure Handbook, Chapter 14, page 215 (available here: http://humanurehandbook.com/downloads/H4/Ch_14_Tao_Compost.pdf)

IT’S ALL ABOUT THE COVER MATERIAL
For a water toilet to function, you need water. For a compost toilet to function, you need a carbon-based cover material. This is the limiting factor with compost toilet systems. If you don’t have the cover material, you won’t have a compost toilet. When I travel to a far-off land to help people set up compost toilets, the first thing I look for is the cover material. You can’t use ashes, you can’t use sand, you can’t use lime, and you can’t use dirt. It must be a plant cellulose material. Cover materials we have successfully used around the world include sugarcane bagasse, which is ground and shredded sugarcane stalks used in the sugar and rum industries, found in most tropical climates. It contains residual sugar as well as cellulose, and microbes love it. Of course, sawdust can be found worldwide. The best is what comes from cutting trees into boards, beams, or posts. Sawdust is not wood chips and it is not wood shavings. Chips come from a chipper and they’re too big for bacteria to eat. Shavings come from planing machines, and they also produce relatively large pieces of wood, which bacteria have a hard time dealing with. In big municipal compost piles, wood shavings may work just fine, given enough time. In backyard compost piles they will slow your pile down, especially if kiln-dried. Rice husks or hulls, a by-product of the rice industry, are often used for cover material. They also tend to slow down the compost in smaller piles, but they do work. The byproducts of cassava distilleries have been successfully used as cover materials when composting sewage sludge in China. Other promising cover materials in compost piles include olive mill by-products and sweet sorghum bagasse. A lady in California emailed me and said that she had been using a compost toilet for years but had trouble finding cover material, so she got a chipper/shredder and started shredding blackberry brambles, describing them as “an invasive nuisance around here...they are very abundant and grow quickly (about 15 feet a year). Smaller branches and twigs with leaves on them (usually willow around here) can also be shredded into a great cover material.”

https://humanurehandbook.com/store/Humanure_Handbook.html

Joe Jenkins

sifted leaf litter works great for me and available any were there is trees.

Tyler Ludens wrote:I don't want to purchase wood shavings for composting toilet, so I'd like to know if leaves and forest duff, of which I have plenty, is a good substitute.  Is there a particular reason people use shavings, or is it just convenience and aesthetics?  Are leaves not sufficiently absorbent?

Thanks for any insight.

From what I have heard, yes, it absolutely is. Toss in a handful of dried, shredded leaves after use and it keeps the smell non-existent. I have not, however, tried this yet as I do not yet have a composting toilet. The wife is vehemently opposed. I am attempting to get her to see reason. Probably not going to happen as this seems to be a hard-limit for her for whatever reason.