you could put the chickens in a coop inside the greenhouse

Keep most of the chickens in a coop and let one or two run around perhaps. A better option than chickens I would think would be game hens, they are smaller and smarter and as a result of there intelegence they do not poop were they eat, the Game hen we had when I was younger would always poop from its roost, never in the food or water, this might work.

Or, even better, you could just lay down a thick layer of straw over the base of the plants, to keep droppings from the soil.

You are correct, Sue, that ammonia build-up can be a problem for plants in a greenhouse also occupied by animals. The Solviva greenhouse had chickens inhabiting it (and rabbits also I believe) and it incorporated a filtering system to remove ammonia from the air. I do not have details of the system.

But I think you are somewhat incorrect in saying the biggest problem is the ammonia effects. The biggest problem, in my opinion is providing adequate ventilation. Heat build up in a greenhouse can be rapid and fatal to small animals and high humidity can have detrimental health effects.

Still, it is an idea worth pursuing.

Wayne

Actually, the Solviva greenhouse had the excessive heat problem covered. The greenhouse was deliberately designed to take advantage of the thermosiphon effect: openings low in the wall of the shady/cooler side of the greenhouse allowed cool air to enter, and vents in the roof allowed the heated air to escape. Even if it got too warm in winter, a few vents at top and bottom could be opened to adjust the temperature.

But if the temp in the greenhouse in winter was adequate, there was a build-up of ammonia. I know she had a relative that designed a filter to eliminate this (and it apparently worked well), but my question is, what would the rest of us do?

Sue

Well, the Solviva greenhouse (and property) is up for sale, though it is in poor condition. I assume she wrote about the filter in the book though and referencing that would probably be a cheaper option. Maybe someone with a copy can refer to it and find out the mechanics of the filter. I expect I'll be addressing this same issue this fall but only with a half dozen birds. (Or maybe not, as I likely won't be growing tomatoes over the winter in my cold climate. The greenhouse in winter will be primarily to heat the chickens, not vice versa.)

Wayne

Well, thanks for posting that, colfax. Using the growing bed soil as the filter makes good sense. I'm not sure if it will be built this winter, but my small (9x12) semi-pit greenhouse will have a coop attached but the goal is more to draw heat from the greenhouse (and from composting manure) to warm the chickens rather than using the heat from the birds to warm the greenhouse. (6 birds wouldn't throw off that much heat when the temps dip to minus 30 or minus 40.)

But the concept as outlined would work to heat the greenhouse with the composting manure in the early spring.

Wayne

The problem I see with that is that the chickens would be in high CO2 high NH3 environment, which tends to not make them happy. When I was little we had 2 hens in a 4X6X4 structure with 2 inches of foam in the walls, it was heated with a 60watt light bulb and they were just fine.

I have been thinking about this for a couple of years and think that a natural filter of duckweed might be affective in keeping the ammonia down while simultaneously providing a food source for the birds. A rainwater catchment system could be used to provided drinking water and the run off could go into a type of ground pool with duckweed growing in it. Waste would drop through a grate into the water where the duckweed would process it.

It is a similar system to the greenhouse aquaculture plans and could probably be incorporated into an existing system.

I welcome any input on the possibility of this idea. : )

I was not aware that duckweed was useful in that regard, but I googled and found that it is true.

But the site I first found said "If the duckweed is to be fed to animals, a retention period in clean water will be necessary to ensure that the biomass is free of water-borne pathogens." This would add at least one step in between creation and feeding. (see more below)

I have the feeling that there would still be an ammonia problem in a small building if you were going to grow ammonia-sensitive plants, but I have no info to back up what is just a gut feeling.

But your idea made my mind jump to Aquaponics... At the Backyard Aquaponics website they use fish waste in water to feed hydroponically-grown plants: the fish water is pumped into the plant beds, the plants remove the nutrients, and the cleansed water is returned to the fish tank. I don't know if this would work for chickens or not.

Thank you for more food for thought!

Sue

Here is a link that might be useful: Practical Duckweed: Application Areas...

Just out of curiosity, how much can a couple of chickens possibly help?

I mean, is there a way to calculate, given a greenhouse of a certain volume, and a given number of chickens, and a given ambient temperature, how much of a temperature increase the chickens would actually confer?

I'm skeptical that it would account for much, but you guys are the experts.

"Never raise rabbits in a greenhouse, it is too hot for them. Even on a sunny day in the dead of winter." Pg 11-12.
Growing Food In Solar Greenhouses by Delores Wolfe.
It is a good book, but "solar greenhouse" is a silly name if you ask me. But in the 1970-1980's people preached "solar" the same way they do "permaculture" now.
Wonder what the new big word will be in 10-20 years?
Maybe Bio-char?
Most of these people just want to sale books.
People have used most of this for hundreds of year with out a book ,web or big words. We should laugh at ourselves once in a while it is good for the soul.

Cdprop:

Chickens give off a certain number of BTUs of heat (I want to say about 65, but I can't find the info). In a more controlled environment (solid walls or controlled ventilation) this can be used to their advantage, and yours.

The problem in a greenhouse is that if you're not very careful, the extreme temperature fluctuations can cause problems.

It would probably take a lot of chickens to heat an uninsulated greenhouse at night (if they were the only heat source), but having that many chickens in there during the day when the sun was shining, the combined body heat plus radiant heat from the sun would probably cause them to overheat and possibly die.

Attention to insulation and ventilation would be crucial.

Sue

Why not dig down 24 to 48 inches, so you can use the earth to hold the heat in. Get white or black plastic 30/55 gallon drums fill of water to put in the corners & use them as tables. Put down about 3-6 inches of gravel on the floor. this & a few lights should keep plants alive all winter.
This is green house 101.

Joji,
do you have any pics of this????? Oh how big could the greenhouse be???
sounds great....
Thanks
jean

Jolj, most of these people care less about selling permaculture books than they do bringing the awareness that permaculture is going to be one of the few ways we can save this planet. At the rate we are desertifying our land with monocropping and big ag, and procreating like rabbits (the earth's population is presently nearly 8 billion humans). When we reach 9 billion, which at the rate we are going will be no later than 2050 - when my grandson will just be reaching his maturity - this planet will no longer have the resources to feed all the people who inhabit it. THEN WHAT? Permaculture people are interested in helping people understand that the ways we live now are NOT sustainable, the earth's resources are finite, and we must change the way we think about how we live must change, or we will become one of the many species we have helped go extinct. Just not workable.

sorry about the double "change" in there......

jeanwedding, sorry for not answering sooner.

http://www.inspirationgreen.com/pit-greenhouses.html

ironwing1, you have a right to your beliefs.

But everyone who sales book do it for the money or they would be Free.

As for permaculture much of that was preached by the hippies in the late 60's & 70's.

Many of the permaculture book are from hippies from that time.

It is part of the earth worship movement & the believer buy the books much like the Chirstain buy their not the sinner who need them.

As for the earth resources Chinese worked this out a thousand years ago without sky high books that all say the something for the same high cost.

When the net/web has most, if not all of it for free.

Places like New York City feeding people Organic plants & fish for pennies.

It is on youtube for FREE.