Perhaps this from Canada Public Health might be of some interest.

Here is a link that might be useful: Pollutants from wood burning stoves

Green Guilt everywhere. ;)

Burning wood does NOTHING to the environment. When a tree is growing it has a negative carbon footprint. When you burn that same tree all that negative carbon footprint turns into NOTHING.

The tree already cleaned the air for the 100 years it lived. The few hours of burning put the carbon back in the air the tree already took out. It does NOTHING.

Charcoal is good for the earth and the microorganisms in the soil.
It is being practiced in many countries all over.

All we need to do is till the soil and spread synthetic fertilizer to grow anything so........

About the ph. If it is ash it will increase ph and add sulfur. If it is washed bio char then it has 7 ph and nothing in it. I made to use as perlite replacment before. If you use it in the field you will not wash it. Spread it light and it wont hurt ph.

I dont know what your soil is like or how much compost u use, but I read something about a field that had so much goat manure on it the over use of ash did nothting to the plants even with a soil test of 8 ph. The natural buffering of the manure allowed all nutrients to be used no matter the ph.

This post was edited by TheMasterGardener1 on Tue, Dec 25, 12 at 17:50

The smoke from wood burning stoves, or from a brush pile since it makes no difference where the pollution comes from, triggers an Asthma attack in those of us with Asthma. Numerous studies have shown that buring wood, even in a wood burning stove, produces large amounts of pollution that are a health hazard even to those that do not have Asthma.
Never spread wood ash on your soil without knowing what your soils pH is along with the numbers for Calcium and Magnesium.

Here is a link that might be useful: About wood smoke pollutants

Diesel combustion is easily the worst contributor of dirty pollution all over, since diesel rigs are everywhere; coal is the worst in absolute terms. Let's be glad we have nowhere to live but industrial China.

These slow-motion regurgitative arguments are amusing in a deja-vu manner...

Burning wood does NOTHING to the environment.

Come out and spend a week down-wind from one of our major forest fires, then get back to us.

whether smoke from a power station or a home fire they are adding pollutants, then the mythology comes in and claims that all that and exhaust fumes (smoke) mess up the climate, not so of course but those who promote it have the ears of the world.

what mayan's, inca's or aztec's may have done as the cleared and burned is nothing more than myth now named bio-char and terra preta. they just simply buried their ash.

so if you can source ash that is not specially made ie.,. fireplace stove etc.,. use it the pollution is already out there, if once sued in your garden it supposedly draws back that pollution or takes down fresh pollution is all again part of the mythology worship.

what i have experienced is that ash (first time i've ever used it) is helping my plants eg.,. egg plants with a good layer of ash below are at least twice the size of others in the same bed with no ash below.

we burnt a lot of trees to get our ash, lots of clear burning happens here where building blocks are around 1 acre. lots of that ash goes to waste and the fires can burn for up to a week.

all i would say is use it, it's all part of recycling for better gardens.

the bio-char proponents seem to make some outlandish claims.

before judging i push no barrows, i make no money and it makes no difference to me what other gardeners may do.

len

Here is a link that might be useful: lens permaculture essay

"whether smoke from a power station or a home fire they are adding pollutants,"

Although not at the same rate in terms of grams of pollutants per btu's of heat. I hope we can all agree on that.

"..then the mythology comes in and claims that all that and exhaust fumes (smoke) mess up the climate, not so of course but those who promote it have the ears of the world. "

You mean the 95% or so of climate scientists? Mythology? Okey dokey.

Once we no longer believe the scientists and their peer-reviewed research, we're doomed. Just my opinion.

"if once sued in your garden it supposedly draws back that pollution or takes down fresh pollution is all again part of the mythology worship."

I am very curious about this. I don't think anyone in this thread has claimed that biochar somehow draws pollutants back out of the atmosphere. Maybe I don't understand what you are referring to. It would not make any sense, and even though I have seen the benefits of charcoal added to soil, I do not believe in (or worship) such a myth.

Len's posts tend toward the incomprehensible, Tox. I wouldn't spend much time trying to decipher....

Yeah, just couldn't help myself. Slow day I guess. :-D

..
"Once we no longer believe the scientists and their peer-reviewed research, we're doomed. Just my opinion."

I don't see myself departing from tox too often if at all but, I'm becoming more skeptical of science as it comes at me in the broader media today.

I don't have the time or inclination to read all the research on any one thing to decipher exactly what that research tells us and, more importantly, what it doesn't tell us. As science is reported to us in the broader media it is another filter we have to consider when we think we understand the science. There are agendas involved in how science is funded, produced, reviewed and, reported. In the true spirit of science I believe we have to look at science with a wary eye. Once we blindly believe and accept everything anyone has to offer, scientists, salesmen or politicians, we're doomed in my jaded opinion.

to sense
..

ah but the worshipers of bio-char(a modern tag) do believe that, they state that any pollution they cause whilst specifically making bio-char is negated once they apply the char to their gardens. maybe some time spent in groups like permaculture might reveal to you what i say.

again judgements leveled my way, again i have nothing to sell or promote other than sense and common sense, if you find other please let me know? i support no political parties or affiliations.

neither do i support some of these fringe sciences who exist solely to support a theory that will never be seen as hard copy fact. appears to me those science minded people or their supporters have no real answer to give to others so they denigrate others personalities.

have a great new year

len

If I have denigrated your personality in my responses, I sincerely apologize, but I don't think I have.

rott: I think the problem lies with science coming 'through the media'. It is indeed a minefield out there, and if you take your science through the mass media...well. I would certainly look with a wary eye - at the media much more than science itself!

It is possible to bypass the talking heads and pundits without having to read 100 journals monthly.

"Come out and spend a week down-wind from one of our major forest fires, then get back to us. "

Forest fires cause trees to release new seeds, which makes more trees. In some forests, fires are needed.

Trees take pollution out of the air. When you burn them they put back just as much pollution as they took out so it does NOTHING.

:)

Well, there are forest fires and other forest fires. Right now, most of the Rocky Mountain west is undergoing massive beetle kills, with 2/3 the standing trees dead and ready to burn. Conifer forests are red and grey with dead trees.

Actually, there are a lot of deleterious effects of massive forest fires, particularly in the larger picture where mountain snows feed reservoirs that retain water for people living in arid landscapes. Faster spring runoff, mud and rock slides, and probably the most insidious, enormous amounts of silt and ash - millions of cubic yards - wash down filling dams and swamping crucial infrastructure. With the fires we had this past summer, affected rivers are still running black.

And nothing like spending 6 weeks running around with a dust mask, coughing, wide spread asthma, runny eyes, etc. This pic is just a small example of what much of the pine forests in the west looks like:

An air quality study was done around here back in the 1970's and those doing the study found that in the fall, when people were burning leaves, major pollutants increased greatly (this when we still had grey iron foundries working) and during the winter when people were using wood burning stoves (this during a surge in popularity of those) the same thing happened. That data was what convinced our county board of commissioners to approve a county wide burning ban.
I was a firefighter/EMT at the time and we had an increase in calls for Asthma and COPD patients during those times due to the pollution this burning produced. Today as one with severe Asthma and emphysema, COPD, I know very quickly when someone fires up their wood burning stove because I start having even more trouble breathing, even inside my house because there is no way to keep those pollutants out.
Burning wood wastes most of the nutrients that would has, although the resulting ash, or charcoal, will have the minerals in a more readily available form. Even in a modern wood burning stove the amount of pollutants released is very high.

Redwoods ONLY release seeds After a FIRE.

Good for the redwoods. :-)

However, the problem here is that these intense fires in over-crowded forests - the result of clear-cutting followed by decades of fire suppression - now accentuated by drought, billions of beetle-killed dead trees, and a 70 day longer (at least) forest fire season - add some strong winds and the result is a sterilized landscape.

Which is why following these intense fires, there is a huge push to get native grasses and such planted before the noxious weeds blow in.

I agree that most wood burnt is done so in an inefficient manner. With severe asthma can you not also detect diesel smoke and when down the street a dirty oil-burner fires up? I certainly can. A difference from wood is that burning heating oil does not leave a useful garden soil improver.

So if in the process of making that "useful garden soil improver" you send one, or more, people to the hospital that still justifies what you did? If in the process of making that "useful garden soil improver" you contribute more CO2 that increases the rate of global warming that justifies what you did?
What about all of the nutrients that you burned up in the process of getting that questionable "useful garden soil improver" that is so soluble that the change in the soil does not even last a full growing season?

"""useful garden soil improver" that is so soluble that the change in the soil does not even last a full growing season?"""

this whole statement is redundant, otherwise the Amazon black soil wouldn't exist to date.

Man, arguing with you is like tilting the windmill. Just around and around. I got time to burn I guess, as you do.

If you are asking if I personally feel guilty about burning wood, the answer is no, I don't. Again, I'll explain to you that we are all heating our houses via combusting some hydrocarbon somewhere. I burn wood much more efficiently than most people do, and more efficiently than most coal-burning electrical plants (lucky you don't have to breathe air down-wind a few miles of one of those disasters), and more efficiently than many heating oil burners. I burn wood hot. Most people don't, because they don't have the equipment that allows it.

What nutrients am I releasing into the atmosphere, BTW?

..
pnbrown - I'm curious now. What kind of wood burning contraption are you using? I have a passive interest in different methods is all.

Thanks in advance
..

unless you're heating your house by wind or solar I don't see how anyone is not adding to the pollution of the atmoshere.

darth: exactly.

rott: I use a masonry stove that I built, simply a pile of mass capable of absorbing the heat from a wide-open burn for several hours. Mine is fairly small because the climate here doesn't call for day-long burns, but one can build it with as much mass as required. Of course if one tries to burn fully hot and efficient in any kind of metal stove one will melt down the stove and/or cook everyone out of the building.

pnbrown,

I agree with you all the way here!

darth weeder,

Even with wind and solar power there is a fairly large startup of manufacturing...like those windmills don't sprout up out of the ground. I also see all of those access roads to the windmills and around here, they have placed them on the very best farmland it seems.

Wayne I'm guessing we're all guilty of killing the Earth in one way or another then. lol

I have no doubt that if we all heated our houses with wood, the atmosphere in colder climates would be much more polluted than it is.

However, technology has improved vastly since the 1970s. Those studies led to emission standards for stoves. Both of mine have catalytic converters, and are supposed to put out In my case I think I'm the only one for several blocks around who heats with wood, so I don't think it's significant.

I do give myself credit for having thought about the pros and cons, rather than just cranking the thermostat.

Posted by darth_weeder z7 NY (My Page) on Tue, Jan 1, 13 at 15:16

"Wayne I'm guessing we're all guilty of killing the Earth in one way or another then. lol"

Its called 'greenguilt'

This post was edited by TheMasterGardener1 on Wed, Jan 2, 13 at 14:51

Or, in its healthy form, it's simply being thoughtful about our footprint. Ignoring the surroundings has caused the demise of many a civilization.

"If in the process of making that "useful garden soil improver" you contribute more CO2 that increases the rate of global warming that justifies what you did? "

Again, this is a falsehood that gets repeated over and over. Trees are part of the carbon cycle. They take CO2 out of the atmosphere to build their tissue, and the CO2 is returned to the atmosphere when they decay. This has absolutely nothing to do with 'global warming.' The CO2 of concern to scientists is that which has been locked up for millions of years underground in the form of petroleum, natural gas and coal. When any 'fossil fuel' is burned, it returns carbon to the atmosphere that has not been there in geological times (millions of years). The burning of wood, on the other hand, only releases CO2 that was in the atmosphere within the lifetimes of ourselves and our parents. Totally different.

Absolutely correct.

Thank you jonfrum, you backed what I said. If you read back I already said that. You worded it very nice though. :) It is fun being right.

If you're already using a woodstove and sifting out charcoal, but concerned about ashes clinging to it, simply put the charcoal in a bucket, add cold water and agitate. The charcoal floats to the top and the ash dissolves and can be poured off after removing the charcoal pieces. We also burn our beef, pork, turkey and chicken bones in our woodstove after the fire has been going a while and the stove is hot. The burned bones sink to the bottom of a bucket of cold water, while charcoal floats. We save the burned bone scraps and use them as a phosphorus and calcium component in homemade fertilizer...

Barbequeue charcoal (as in, the oval lumps) has binders that I know are toxic to plants. *Activated* charcoal has a high degree of porosity, and stuff binds to it effectively. I think it may push pH down slightly. That being said, I believe that activation has a finite lifetime when exposed to water, though, so it probably won't work for very long. For precisely that reason, air filters that are advertised as making use of activated charcoal are known to do pretty much nothing. Of course, wood ash is entirely different. That is highly alkaline. I have alkaline soil, and I consider wood ash to essentially be toxic waste, with respect to gardening. I bury my wood ash in a corner of my lot.

>>*Activated* charcoal has a high degree of porosity, and stuff binds to it effectively.

"Activated" does indeed refer to the porosity, or more precisely, the surface area, which can be up to hundreds of square meters per gram of material. The porosity is microscopic in scale. Under an electron microscope, it looks like a very spongy sponge.

If it's actually pure carbon (as opposed to something like coal or peat, which have all kinds of functional groups attached to a carbon skeleton), that's a nonpolar surface and ions (salts) will not be particularly attracted. What 'sticks' best are organic molecules like hydrocarbons, fats, proteins, etc. As well as pesticides, petroleum, almost any organic molecule.

>>I think it may push pH down slightly.

Google reveals a general consensus that it reduces pH slightly. That may be due to a certain amount of acidic functional groups on the surface (similar to peat moss which is also acidic). I don't think it would be a strong effect, or long lasting.

>>That being said, I believe that activation has a finite lifetime when exposed to water,

I don't know that water has any effect on it at all. If you stored carbon in water with nothing else, it would just sit there. If it's in soil, there are all kinds of natural chemical compounds floating around, plus fine clay particles, and microbes. Microbes love to live on the surfaces of activated carbon, which will eventually start plugging it up (aka 'biofouling' when it's something you don't want). When used in the garden, it's actually a beneficial effect, as I understand it. More microbes per volume of soil due to the higher surface area for them to live on.

That's a fair point about activated charcoal lifetime. The lifetime is usually limited by getting it saturated with absorbed pollutants. But that can happen pretty fast, especially in water. The pore sizes of activated charcoal, BTW, are tens of nanometers across. Big enough to bind a molecule, but hardly big enough to host a microbe. Microflora and microfauna are an order of magnitude larger. So I don't think microbes would look at activated charcoal as a place with lots of living space to stretch out and kick off their shoes.

I have been growing legume trees for 20 years, burning them and fixing the charcoal in the soil where it effectively wont break down. Also take the mulch from the leaves to my veg garden. The carbon in the soil where i grow my legumes hasnt decreased. The legumes are 6 metre tall in 18 months and i dont have to water them. Not much smoke is prduced to get the charcoal as it is softwood and changes from wood to coal quick. So much more carbon is taken from the air than what goes back to the air. Only have to do this to turn dead soil into alive soil very quickly. We need to burn more wood and not let it rot and get the carbon Into dead soils, rather than the air

Re-scanning this thread, I had the same thought. Something that was not really discussed (unless I passed over it) is that putting charcoal into the soil FIXES the carbon instead of putting it back into the air. And since charcoal is not itself degradable back to CO2 in the soil, it's a net fixing of atmospheric carbon..

The comments about air quality and asthma are well taken (by me at least) and in case this wasn't said either: it is highly dependent upon your location, density of population, background air quality, etc. If I lived in a smoggy city, I would not be making biochar. As it is I live in a small city 100+ miles from any bigger ones, and I don't even make biochar, i just harvest charcoal from my stove ash. I don't think I'm doing any more harm here than burning fossil fuels to heat the house would. YMMV.

Leaving aside the carbon-fixing aspect of burying charcoal compared to burying wood - I'm a little uncomfortable with the statement that "making charcoal doesn't produce much smoke" from an air pollution perspective (it might not be much in terms of CO2, I grant). From what I understand of the process, it's the first part of that process - where the components of wood that don't end up as carbon volatilize and partially burn and are turned into gases and particulates - that's going to produce the nastiest air pollution. In the same way that the nastiest smoke/particulates are at the start of firing a stove and getting it up to temperature, or just operating a woodstove poorly. (Now if someone is doing this as an industrial process with a sealed chamber - i.e. true pyrolysis - this might be different, but I presume we're not talking about that)

Thanks, 'cause substoichiometric levels of oxygen during pyrolysis (used to produce high volumes of charcoal) aren't exactly what I'd call clean, either.

Unfortunately, we've discovered that carbon residency in the soil isn't nearly as long as we'd hoped, either, which was a bad blow for cycling carbon into surface soils. Still, it's going to vary widely by soil type and rainfall. I can't remember if that was in Nature or Science or one of those other ones some years ago, but it was something like that.

I hope I didn't misspeak by introducing pyrolysis but yes, my point was precisely that while producing charcoal might return relatively little CO2 to the atmosphere, it's a dirty process (in terms of non-CO2 pollutants). So I'm a bit skeptical of the overall benefits of charcoal (home-made in particular) if the price of somewhat less CO2 in the atmosphere is air pollution. Of course it depends on what we're comparing it to.

That's not to say it may not have its place in some situations and 'incidental' charcoal buried is perhaps a different story. And I admit I'm not sufficiently well read on the soil carbon/char cycling and all that to weigh in fully. I'm personally inclined to say wood/organic carbon rotting will at least leave some in the soil, at least compared to a lot of the altneratives. But again, not fully up on the science part.

If you're burning wood which would otherwise rot in the woods then you're not necessarily increasing pollution as rotting wood also produces CO2. I won't argue whether it's more or less but if you're burning it to heat your home then you're also burning less gas, oil, or electric than you otherwise would

I live on a wooded acre and a half, my neighbors have similar sized lots, and the property to the east (downwind) is 13 acres and wooded. I watch the wind direction before burning. I pick the big "clinkers" out of the ashes and apply the remaining ash to my garden.

"apply the remaining ash to my garden"

That can be a mistake; ash has a high pH (potassium carbonate, mostly, but for other reasons as well), so blind application can shift your soil balance pretty badly. Plus the non-volatiles will include most of the heavy metals the tree concentrated in its wood, which you'll end up depositing in your garden.

The general recommendation is about 10 pound per thousand square feet per year of blind app maximum without a soil test, for a few years only, as it's the equivalent of a liming, except that the lime is impure, and the impurities aren't what you want to be adding...

I have large expanses of lawn that are or were really moss. It makes a nice lawn as if you're looking out at it. It's green but doesn't need mowed so often. If you're looking down at it; not so nice! I'm now converting much of that to a veggie garden. I applied manure, lime and wood ash and it wasn't enough. I had a few tomatoes with blossom end rot till I put more lime.

I doubt I'll make 10 pounds a year burning brush and an occasional dead fall with a few fallen limbs mixed in.

"If you're burning wood which would otherwise rot in the woods then
you're not necessarily increasing pollution as rotting wood also
produces CO2."

I'd distinguish CO2 and other greenhouse gases from air pollutants with health effects. Burning even waste wood definitely creates more air pollutants. And rotting logs etc both release CO2 over a longer period of time, and usually do not release it all (or over very long timeframes) - lignin in particular doesn't usually breakdown fully (much more slowly).

At my last home I had a large enough woodlot that I could and did attempt to heat that home by burning wood. It worked down to about 35°F. I did that for about 20 years using trees that died or were damaged. Over that period of years the deadfalls would have rotted in the woods. I would argue that I prevented pollution. As would anyone who burns wood over a long enough time period that whether the wood burned or decomposed in the woodlot the wood would have released the CO2.

At one point I was having problems with the chimney and didn't burn wood. My gas bill went so much lower that the gas company called to check and then also hand delivered the bill to get an explanation.

@John, I wasn't trying to pass judgment and apologise if it sounded that way. Just discussing.

A meandering discussion: I was trying to draw a distinction between air pollution (e.g. particulate matter) which burning wood does cause; and greenhouse gases on the other. (I was mostly making this point in the context of the charcoal-in-soil issue - where making charcoal may not produce much CO2 but sure does produce air pollution)

Air pollution: there are contexts in which burning wood makes sense and for those in more rural locations - I understand it; but it does produce air pollutants like particulate matter that have negative health effets - but concentration matters therefore distance etc from others matters. (I still think gas preferable if available from air pollution perspective but I'm not passing judgment - unless you live next door to me and are burning your wet leaves, in which case you'll definitely hear from me).

Greenhouse gas discussion a lot more complex - I won't pretend to know how to best calculate GG trade-off between eg wood and gas, and if you need heat, you need to get it from somewhere. (Apart from other issues, methane leakage from pipelines and production probably worse than the CO2 from burning it). Not everyone gets cheap electric heat from hydro (including me).

I was only making the point that when trees rot, not all gets converted into CO2, and how long it takes to get turned into CO2 matters from a GG/climate perspective. But that doesn't say much, the choice isn't usually burn it or leave it on the ground, but rather burn it or get the heat from some other source, and that other source matters. (And there are other factors like cost)

And I'm just discussing here. I have an occasional wood fire for pleasure, I'm not a fanatic.

armoured - We have a fireplace here and the old wood stove stored in the basement, but unfortunately DW can't take the smoke. So I save some firewood with the understanding that if we have no heat she's going to have to beg me to light a fire.

Thus my reasoning for watching the wind direction for lighting a fire. Myself I love the smell of firewood and smoked food. I'm alone there also. Also I remember the smell of people in the city burning coal many decades ago. I hate that smell. I once got paid to shovel the coal of the confectionary next to my grade school into his coal chute. Folks have made a lot of changes without all the hoopla and histrionics.