Deep Litter Composting With Chickens
About an 8 to 10 minute read | 25th April, 2022
An earth-floor, deep-litter system has big benefits for the health and well-being of chickens, and it's also the easiest way I know to build an ongoing compost creation system in which most of the work is done for you.
This article shares what we've learned about deep-litter composting since we built our new earth floor chicken shed in 2019.
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In 2019 we came across a second-hand kit shed that had been sitting unused at someone's place. It gave us an opportunity to do something we had been wanting to do: build ourselves a dedicated chicken shed with an earth floor.
In "Eight Advantages of Deep Litter," I explained why an earth floor allows for in-place composting of the chickens' bedding and manure that's much more difficult on a concrete or wooden floor.
It's called a deep-litter system. It has big benefits for the health and well-being of the chickens, and it's also the easiest way I know to build an ongoing compost creation system in which most of the work is done for you.
This article shares some pics of our chicken-litter composting adventures since we built the new shed, and what we've learned along the way.
Deep litter composting 101
Successful composting requires 5 main ingredients:
- micro-organisms, which come from the soil below the litter or below the compost pile. (If you need/want to set up a deep-litter system with a concrete or wooden floor, I've mentioned some ideas for that as well, below.)
- carbon (dry, brown, absorbent materials like dead leaves, twigs, hay, straw, shavings, wood chips)
- nitrogen (moist, fresh ingredients like green grass, manures, kitchen scraps, etc)
- oxygen, for the micro-organisms to breathe (incorporated as the chickens scratch and turn the litter)
- moisture (not too much and not too little, as you will see in the relevant section below)
Let's go over them one by one, and I'll include the things we've learned along the way. (You can click on the pictures to see them more clearly.)
Microbes/Earth floor
Sep'19 - first bales of hay on the new chicken shed floor
The very beginning: scraps, chicken manure, hay. Let the scratching begin!
At this stage it's just hay on top of dirt; the only thing for a chicken to eat is grass seeds from the hay and the odd insect.
Nov'19 - the hay is breaking into smaller pieces and the soil underneath is beginning to look darker.
Step one is an earth floor, so that soil microbes can move up into the litter and bring it to life. In essence, we're mimicking what happens on a forest floor: a variety of stuff falls in layers on top of the soil, and then teeming masses of microbes convert it into more soil.
What if you have an existing wooden or concrete floor? You can still use a deep litter system and it will still greatly benefit your chickens, but:
- it will help if you inoculate the litter with some healthy soil and perhaps some bio-active compost at the beginning and periodically along the way,
- it will be much more important to get the moisture levels and aeration right, and
- after it comes out of the chicken pen, your litter may need to be aged in a conventional compost bin/pile with an earth floor, before putting it on your garden
The final section in this article describes one way to go about setting up a deep litter system on a wooden floor.
Carbon and Nitrogen
The next thing is to get the balance of carbon and nitrogen right. We're after at least 25 to 30 parts of carbon (dry, brown, absorbent materials like shavings, dry leaves, small twigs, hay/straw) to 1 part of nitrogen (in this case, chicken poop, but it could also be other fresh manures, fresh green plant material, kitchen scraps, etc).
Some carbon materials (think shredded paper or dry grass clippings) can't absorb much moisture and are apt to get slimy -- not good. Others (think large wood chips) might be difficult for the chickens to mix and stir around -- also not good. What we want is something absorbent and mixable.
Our sickle bar mower enables us to cut long grass to make hay for topping up the litter.
On the day its spread out, and...
... a few days later, gradually turning into hay.
We cover the entire floor of our chicken pen with litter, but we concentrate our composting efforts under the chicken roost since that's where the most chicken poop lands.
We started out buying large round bales of mulch hay to provide the carbon for our chicken litter. Then Alain bought a sickle bar mower machine with which to cut our fast growing, coarse tropical grasses.
We've found that the freshly cut grass dries out, goes brown, and turns into perfectly adequate hay as the chickens turn it (see pics below).
When we import it, green, we spread it in the main area of the chicken shed, but not under the roost where the most chicken poop is -- that would be way too much nitrogen for that area. We wait till it's turned brown and been broken up into dry, fluffy, hay before forking it under the roosts.
I've read here and there that hay isn't a good choice because of the chance of mold spores, but for us, it has worked fine. Our current system of bringing in coarse, freshly cut grass and turning it into hay in the shed has an extra benefit: it gives the chickens a chance to go through it for insects and eat some of the leafy parts while they're still green.
Then as they continue to search through it, they break it up and fluff it up, which helps it dry out faster and probably makes it difficult for any mold to establish itself.
This started as long, coarse, freshly cut green grass (see pics above).
The same material after a bit more scratching and mixing by the chickens...
... and still more scratching and mixing...
... until it turns into done-for-us chicken litter compost.
I think its important to note that the cut grass we bring in is long and coarse, not lawnmower clippings. Lawn mower clippings might get slimy, stick together, and form a moist mat. This would be difficult for the chickens to turn and aerate, which is necessary for converting the green, moist grass into dry, brown hay.
So if you want to try using grass as your carbon source and you only have a lawn mower, you might need to be a lot more involved in helping the chickens turn and aerate the clippings until they're dry, brown, and light and fluffy, before expecting them to serve the function of a carbon source in your litter.
To recap, topping up the litter in our chicken shed goes like this:
- We fork some of the old, dry, fluffy, broken up hay from other areas of the shed onto the area under the roost, to top up the carbon there. (This is also where we add all the kitchen scraps including egg shells, and it's where we throw the chickens' grain, to encourage them to keep scratching it up and turning it over.)
- Then we bring in freshly cut, coarse green grass and spread it on top of the remaining old dry hay in the rest of the chicken shed. For a day or so, the chickens are very busy catching insects in it and eating the green leafy parts of it. Then gradually it dries out and goes brown and gets broken up and mixed with the previous material.
Moisture
Compost should have the moisture content of a wrung-out sponge when you squeeze it. It should stay loosely together when you open your hand, not in a soggy clump, but not crumbling apart either. (Note that in the bottom right pic, above, the compost is still a bit too dry; it crumbles apart completely in the open hand.)
In the early stages of this project we were assuming that the chicken manure would provide enough moisture, but it turned out, it didn't. And although we live in a wet climate, the earth floor for our new chicken shed was slightly raised and the surrounding area falls away from it. This seems to have been enough to keep our litter drier than ideal.
In contrast, where we lived previously (described in "Pros and Cons of Free Range and Mobile Pens" and "8 Advantages of Deep Liter") the earth floor of the chicken coop regularly flooded, then drained again within a day or so. That too was a deep litter system, and it worked beautifully. I don't recommend ever flooding your chickens' home on purpose, but you do need to find a way to get the right moisture levels in there.
We solved our lack-of-moisture problem with the addition of sprinklers under the roost.
Our roosts, with black piping and upside down sprinklers tied on underneath with zip ties. (Its very hard to see the sprinklers. Sorry.)
The sprinklers sped things up noticeably. In hindsight, we should have done it right after rolling out the hay and moving the chickens in; I think we would have had finished compost a lot sooner.
Oxygen (or aeration, provided by the chickens' scratching)
We've found that when the system is working well, the amount of time we need to spend in there with a pitchfork is minimal.
BUT, you will have to get in there and turn the litter yourself if for some reason the chickens aren't managing to get the job done. Unless the litter is turned and aerated consistently, the beneficial, oxygen-loving microbes will die back and all you'll have is a stinky mess full of anaerobic bacteria that are not at all health-promoting.
If you're having to wield the pitchfork too often, ask yourself, "Is there enough carbon? Is the carbon easy enough to mix? Is there too much moisture?"
Healthy compost is irresistible to chickens. If they're not scratching away at it diligently all day long, they're telling you something's wrong with it.
Harvesting the compost and never again cleaning out the hen-house
Harvesting the compost is the best bit. It's simply a case of scraping aside the top layers of the litter until you get down to fully composted, dark, rich, friable, sweet smelling stuff that looks like it has come from the floor of an old growth forest. Magic.
If you have terrible memories of being the one who had to clean out the chicken coop when you were a child, take heart. Done right, a deep litter system is forever. You're in charge of keeping the 5 ingredients in balance, but you can leave the cleaning to the microbes, just as nature does on a forest floor.
Now, that makes me wonder if I could invent a deep litter system for the floor of our house...?
Resources and related posts
You might enjoy these related posts on A Real Green Life:
- Pros and Cons of Free Range and Mobile Pens for Chickens
- 8 Advantages of Deep Litter
- How to Keep Chickens Happy in Confinement
My all-time favorite chicken resource is The Small-Scale Poultry Flock by Harvey Ussery. You can find his chapter on deep litter in the hen house, here.
If you live somewhere that gets proper winters, this is a great read too -- scroll to the end of it for his use of hay as deep litter during the winter.
Finally, here's an article about moisture levels in compost.
Please leave a comment...
Please share your own composting set-up, or questions and other thoughts, in the comments -- thank you!
A reader commented by email:
“Kate,
This post begins to address a topic I have long had trouble with. That is moisture content of the litter. You specifically added sprinklers and apparently that works well for you. I own and have read Mr. Ussery’s book. From the links you listed in the second of his posts he says,
“The litter should never be wet. Wet litter is anaerobic (lacking oxygen), a condition conducive to certain pathogens, in contrast to decompositional microbes, who thrive with abundant oxygen. Should wet spots develop—for example, around the waterers—again use your spading fork to disperse the soaked material out over the rest of the litter, where the scratching of the birds will dry and aerate it. (Don’t be concerned about a little water, however. I often swish out the rims of waterers onto the litter in order to rinse. The resulting increase in moisture, if not excessive, actually benefits the microbial processes in the litter.)”
That seems to lean toward drier litter. Elsewhere in his writing he has written of his chickens taking dust baths in the litter and that is closer to what mine is now like. Is your litter like a “damp sponge” over the entire floor or just under the roosts? My plan from this point is to add some water to try to maintain a “damp sponge” moisture level in about one half of the coop and see what happens. Oh, I am on an earth floor now.
Anyway, thanks for addressing this issue. My chickens do a lot of scratching and they seem happy, but perhaps this is the nudge I need to improve the situation even more.”
My reply:
“Hi, thanks for writing.
the sprinklers only water the area under the roosts, which is where we focus our composting efforts since that’s where most of the manure falls. We have found that more moisture here has sped up the composting process and made the material seem to move more quickly from raw materials toward a pleasant smelling, dark, crumbly, full decomposed state.
the rest of the chicken shed is as you describe: the chickens can take dust baths anywhere that the litter has thinned out enough for them to reach the earth floor.
i would say that over the whole shed floor, the process is something like this:
– green, coarse grass comes in and is spread in areas OTHER than under the roosts
– it dries out and is broken up and mixed into the older dry materials by the chickens
– some of it is moved under the roosts to top up the carbon there, and this is where the real composting process begins, with the proper balances of carbon and nitrogen, moisture, and aeration.”