Jason Aramburu

Founder & President, re:char

This conversation is closed.

Burying charcoal to improve crop yield and offset CO2

I am involved in work to develop biochar technologies. Biochar involves the burial of charcoal in agricultural soils to improve crop yield and offset CO2. By converting decomposing, agricultural waste into biochar, we can sequester up to 2 billion tonnes of CO2 each year according to the journal Nature. This represents around 12% of global CO2 emissions. I am interested to hear the thoughts of the TED community on the potential of biochar, particularly in the developing world.

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    May 2 2011: Anna thanks for the kind mention. My woodgas cookers (http://bit.ly/C-ve )are domestic scale, extendable to shared/communal cooking. Space heating or industrial use of woodgas/biochar would need something more intricate than my tin can tech. Liquid woodgas-based fuels are interesting as a replacement engine/boiler/generator fuel but would expect that direct burning of the woodgas is more efficient if you don't really need a liquid (?).

    Biochar is vital for reviving both soils and climate so I want to see people using woodgas cookers daily in both 'developing' and 'developed' countries. Most of the energy value of dry biomass is in the woodgas rather than the charcoal! Woodgas cooking should coincide with a world-wide end to charcoal making processes that emit unburnt woodgas to air since this is hostile to both health and climate. With unseasoned wood it's also ridiculously inefficient for delivering heat for cooking.

    I'm fond of hardwood twigs for my cookers since the same volume of fuel burns for longer. However a preference for hardwood seems to be a legacy of wanting hardwood for cooking-charcoal. When using softwoods or agricultural wastes in woodgas cookers with biochar byproduct you can get any desired cooking time just by adding more fuel. The resulting lighter-weight charcoal is easier to crumble into compost so better than hardwood biochar IMHO.

    Well done Jason with your excellent work. Also well done you and Lindsay for your sensitive help for George, who I'm hoping will be curious now to try it for himself :-)

    Rolf, the question of scale is interesting. Big biochar machines is one way to get scale. Large numbers of small machines (woodgas cookers) is another. Both can provide large-scale agricultural use though the potential for mishandling of biomass is greater with the big-business approach. The economics is also interesting; a combination of biochar business finances and wider economic reforms that have barely begun, http://bit.ly/CoLabEntry
  • Apr 30 2011: Hi Jason - I've done a bit of study on the economics of biochar application in Canada. Bottom line: we need to get production costs down to make it viable for large scale agricultural use. It's been a while since I read Lehmann's excellent book, but the production economics differed a fair bit from what biochar producers tell me.

    As biochar plants get big and economies of scale improve, the feedstock radius increases raising the price of the straw or wood etc. We've blue-skyed a bit and mused that it would be theoretically most efficient to have combines that pyrolyze straw during harvest, but residence time required for pyrolysis would likely make the required onboard storage massive.

    To get the industry off the ground, small high value markets are needed. Some small producers here are selling into retail horticulture as garden soil amendment. Other profitable niches could be the hydroponic greenhouse market as growth media. One of our government reserarch greenhouses under Dr. Nick Savidov here has done extensive testing and found that almost every type of biochar tested lasts much longer than the coconut coir they currently use so could lower labour costs with equal or slightly better yields. Biochar is also less susceptible to fungus growth in this application.

    I know the USDA has several technical programs but is anyone aware of any North american farm application economics studies?

    Keep up the good work!
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      May 2 2011: Thanks for adding this..maybe a basis for a part II??? Jason May have had it with us here at TED..weve kept him on line for 60 days here on this but now that the ground work is laid and folk have been introduced to bio char and its possible implications for increased food supllies and local community growth..end of fertilizers and chemical insecticides..are we ready for a part II that explores exactly what you ask here..Can we bring this to larger scale production and how? What crops to we focus on? etc.. I would love it obviously...and in fact..off to put charcoal in a new sunflower bed....
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        May 5 2011: Hi Rolf and Lindsay,

        Great points. Horticulture has been named as one of the initial markets for biochar in North American and Europe. Yes, larger-scale biochar production is quite possible. We are very interested in community or home-scale biochar use in the developed world. The question for us is-- do Western consumers prefer to purchase a simple device to make their own char, or purchase already made char? In Africa, cost constraints and abundant labor favor the former, but things could be different elsewhere. Any thoughts?
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    Apr 15 2011: For more info, please check out the below nature article on biochar and re:char:

    • Apr 15 2011: Read it, but I still don't get it.

      Crop waste is best processed when composted; composting creates it own heat and the finished product is readily available to the soil microbes which sequester carbon.

      Farmers have been adding carbon, in the form of soft coal and/or burning off their field stubble for centuries.

      As an Ag guy I'm not seeing the advantage.
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        Apr 17 2011: See Terra Preta..composting alone requires continual ammendment ..charcoal, once it reaches a certain mass in the soil is a permanent everliving ever renewing soil matrix The charcoal has a compex biochemical relationship with the plants.with resulys that composting alone can't match in yield, drought tolerance and resistence to insects and blight. The original Terra Preta was a compost+bio char system but I'm not sure modern science knows the formula exactly. I use about 2lbs/100 sq ft .in organic seafood composted soil.
        • Apr 17 2011: I've been in farming since the 60's, first with chemicals then organically. Composting does not necessarily need amendments, it depends on your soil condition.

          If you want to make claims about the char then please supply data links not platitudes. I need the results of the testing, and the baseline for your testing methodology, to believe this sales pitch.

          I've worked with organic farmers all over the US and the world, different soils, climates, crops, and scales of farms from corporate to poor farmer collectives. We get that carbon is important but I have seen so many silver bullet products, that have promised unbelievable results in the fields, only to discover yet again there are no silver bullets.

          In the early days of organics farmers would study old Ag books from the 1800's or earlier, reviewing many farming methods, even of ancient peoples, anything that could make organic farming better. Dumping car into the soil never came up. Too much char could knock your N off the colloid. Too much of any Ag input can be bad for your soil.

          I look forward to the data
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        Apr 17 2011: (Don't know how to make this follow your latest comment....) Well here's the Wikipedia Link on Terra Preta..the ancient amazonian soil http://en.wikipedia.org/wiki/Terra_preta. lead you to what science there is..I have seen two documentaries on it and what I recall is that no one really understands the exact formula for creating a terra preta soil that is a living matrixso I think you may be right that the science on this is ongoing...I no longer grow for sale and am no expert..I just do things yankee style and am always willing to experiment. I have no question that charcoal makes a huge difference with my crops. Perhaps Jason can point us both to the best science on efficacy of charcoal and give us some guidance on the right mix?
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        Apr 17 2011: It's true that microorganisms do break down organic carbon, but they do not sequester it. Soil respires CO2 like any other living organism.
        • Apr 18 2011: Please supply link to physical soil sequestration; beyond the normal atmospheric capture between the soil particles.

          When I ask for a link it;s because I failed to find the info on Google or other search resources. Don't mean to be a pain the ass, I've been a proponent of living soil for 25 years and love new ideas, but this one is just not adding up for me.

          Do you have an energy chart flow on Ag waste to char?

          If the data is there to support your claims then it;s all good.
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    May 12 2011: This conversation ends soon so thanks Jason!

    Biochar is my pick for the practical solution with the greatest potential to really turn things around in time. Greenhouse gases can be removed from the air, soils can be revitalised, ecosystems and forests can be renewed, food security can be regained. All of this can be done in every country, cheaply, simply and fast - let's do it.

    I'd like to open-source my design for an easy make-it-yourself biochar woodgas cooker so if anyone has thoughts on possible start-up funding or international collaborators please contact me via my TED profile. Thanks!
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      May 12 2011: Ditto..all the way across Jason..thanks for hanging in here for 60 days with us. and thanks for your good work.
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        May 12 2011: Thanks all. James, would be interested to learn more about your design.
  • May 11 2011: Potash is a fertilizer which originates from burnt out forests in Canada. So maybe there is something to it.
  • May 5 2011: Hi, this is an interesting idea but I do have some doubts:
    First, what source of energy do you use to create the pirolysis process? And how do you retain the formed gases?
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      May 9 2011: Energy is derived from combustion of the pyrolysis gases.
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        May 9 2011: oh dear..
      • May 10 2011: Thanks for your answer. I can see how it may sound rather stupid and I apologize for that. As far as I can tell based on the articles you have provided, it basically is removing the volalite gases trough pyrolysis much like a normal combustion would but by maintaining a low level oxygen atmosphere you can provide a limited oxidation of carbon hence maintaining more carbon than a normal combustion would. But the formed gases is where I have most doubts. How do you control emissions of NOx and/or SOx as well as aromatic compounds? Thank you once again
      • May 10 2011: Also, have you considered transforming the created biochar into activated carbon and thus enable more carbon dioxide sequestration?
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    May 2 2011: HI! I am joining this late in the conversation but I am wondering whether or not biochar is the reason that soils are so revitalized after extensive forest fires?
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    May 2 2011: I know traditionally our poor & "illiterate" farmers in old days cahrchol produced at their home after cooking with fire wood used to use in their fields. Even after reaping crops also they used to burn rest of the crops parts remained in their field then mix the same while ploughing.
    Later fertilizer & insecside marketers made them to de-learn their that practical and instinctive knowledge ................ Good news you are working on that, success depends on commercial success. In this era nothing is implemented if it is can't proof it's immediate commercial or economic profitability in terms of dollars only.
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      May 2 2011: Salim..So interesting to hear that the practice is ancient in other cultures around the wolrd.Did you grow up in Bangladesh? And byyour comment do I understand it wasn't actually still prcaticed as you were growing up? What lead to its discontinuance, do you know?
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      Apr 24 2011: George,

      I've answered all your additional questions below. Unfortunately, this will be my last response to you unless you wish to engage in a meaningful discussion. When you asked for 'data,' I provided you scientific papers. I'm a scientist, and I know of no better data than peer-reviewed scientific papers. Also to clarify, we have ongoing collaboration with several universities including Oxford U and Princeton. We have also raised considerable funds from private investors and grant foundations. In all cases where we have communicated with fellow scientists, professors or investors, they have greatly appreciated reading the peer-reviewed journal articles we send. Thanks for your time.

      Charcoal is a form of mineral or inorganic carbon, unlike organic carbon (compost, humus etc). Organic carbon is typically in the form of cellulosic materials like lignin and can be decomposed by microorganisms, mineral carbon cannot.

      Adding organic carbon to soil itself does little to stimulate plant growth. At best, it can help insulate roots during periods of cold temperatures. When organic carbon is composted, the microbes in the compost pile digest the organic carbon and concentrate the small amount of NPK present in the green waste. If one can produce sufficient amounts of compost and add it to soil, this does improve plant growth.
      Biochar improves the physical structure and adsorption of soil (as I have said several times). It improves the soil's ability to retain nutrients (NPK), water and microorganisms. In practice, adding biochar to soil makes compost or fertilizer much more effective by reducing runoff. It also fosters microbial activity in soil, which improves nutrient cycling. It is not as though biochar is a replacement for compost or vice versa. Feedstocks that make poor compost (wood chips, husks, cobs, pits, shells etc) make the best biochar.
      Burning ag waste is totally energy efficient. The only energy 'lost' is the energy in the match used to light the waste.
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      Apr 24 2011: We mitigate long chain carbon emissions during the pyrolysis process through efficient combustion design. Our team has 40+ years of engineering experience. To answer this question in more detail would require us to disclose proprietary information about our technology, which I have little interest in doing for a stranger on the internet.

      As I've said, I don't understand what you mean by an 'energy flow chart.' Burning ag waste does not require additional fuel inputs. We work with poor farmers in Kenya who farm totally by hand. They manually load and unload the units.

      We find up to 10 tonnes/ hectare of char can be added to agricultural soils before improvements in yield plateau. Studies have tested concentrations up to 20 tonnes/hectare and found no adverse effects on yield or germination. It is conceivable that concentrations higher than 20T/hectare could reduce yield or lead to 'nutrient imbalance' but it would likely take decades to produce that much char in-field.

      Fast-growing, water-hungry crops like corn and rice respond the best to char, followed by vegetable and green crops. There is currently insufficient research on the effects of biochar on slow-growing tree species, but this is an emerging topic for many scientists. In general, acidic, weathered tropical soils respond the best. As I said, it's not as though biochar is a replacement for compost. It improves the effects of compost. We find that in Western Kenya, manure+biochar outperforms DAP (chemical fertilizer) 2:1 and plain compost 1.5:1 in staple crops including corn and beans.

      We have 750 smallholder (1-acre) farmers in Western Kenya using biochar. They are our focus. Charcoal is produced from sugarcane and corn waste that is otherwise burned in the field. This is about as 'down to earth' as one could get, and would have been clear if you read my previous responses. As I've said, please take the time to read and understand before jumping to conclusions and responding.
  • Apr 20 2011: Jason,
    Ethanol thrives here because Ag Corporations wanted to loot more taxpayer dollars from the US Treasury. The US ethanol policy has successfully tied the cost of food to the cost of energy, it's a complete disaster.

    Ethanol is done right in Brazil.

    The real problem here is that you've haven't completed all your homework on this project. When you get all your data together, not hidden behind firewalls or such, make a clear concise presentation as you would for any presentation, as opposed to asking readers to do their own research.

    There is no doubt about your sincerity, only your data.

    Thanks for the conversation.

    PS: Look into to Exhaust farmings, where the exhaust from the tractors is cooled then pumped into the soil as the tractor moves across the fields. Yields are up and pollution is down, http://www.weeklytimesnow.com.au/article/2010/12/08/269141_print_friendly_article.html
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      Apr 20 2011: George..I don't appreciate your deunciation of Jason's post here..that is not the spirit or the rules of engagement for particpating here.. I also disagree that Jason's references to external data and info are a "firewall". I use all the links provided in cinversations I'm following and participating in nd find them very helpful in elevating and focusing the conversation on any topic. Also, doesn't really good conversation, even "around our own campfires".include a mix of thoughtful consideration, expertise, questions that point to good thought or good inquiry and ideas that hold promise for many?
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      Apr 20 2011: Agreed, this really isn't in the spirit of the discussion, George. I've provided 3 peer-reviewed scientific papers to you that validate Biochar, having never met you, and I've given you the direction to find many more. If you're interested in actual scientific discussion, then you are free to take the time to read them. The article you've sent is not peer-reviewed, provides zero data, only the anecdotal reports from the device's developer. If you'd like to engage in a real dialogue, please take the time to thoughtfully consider the facts presented and then make a reasoned case for or against them with sound supporting data. I'd prefer that this discussion did not degrade into Internet trolling and flame wars.
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    Apr 18 2011: The prevailing theory is that biochar's benefits were discovered by accident. Indigenous peoples in the Amazon basin typically threw out their refuse along with the remnants of their cooking fires in large piles. Over time, they noticed that these areas tended to be more fertile, so they continued the practice. In our tests, and those of others, biochar + compost is significantly more effective than using compost alone.
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    Apr 18 2011: http://www.nscss.org/system/files/Lehmann2006.pdf

    Please read through the above paper, which is freely available, from the leading biochar research lab at Cornell U. It explains the sequestration benefit in very clear terms with supporting data. I'm not sure what you mean by a flow char. Are you interested in the energy cost of making biochar?

    To paraphrase the above article: Biomass waste normally decomposes and converts to CO2, methane and other carbonaceous gases. When it is converted to char, it will not decompose back into CO2. When the inert char is buried, the carbon is sequestered on Earth rather than returning to the atmosphere.
    • Apr 19 2011: Read it. http://www.nscss.org/system/files/Lehmann2006.pdf

      ..."These economic aspects as well as any social aspects are not resolved in this paper, beyond considering the implications of C emission trading, but are important for the successful implementation of a bio-char system and such studies should be conducted in the future.".....

      ...."Additionally, the decomposition of bio-chars is most likely reduced when it is transported down in the soil profile or buried in river, lake, or sea sediments...."

      ...."It appears that the effects of bio-char on N dynamics in soils is not entirely understood."....

      Char is beginning to sound a lot like Ethanol
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        Apr 19 2011: Hi could you please clarify that statement? The quotes you cite just indicate that more research is necessary beyond the scope of this one scientific paper, which was written in 2006. Unfortunately, this is the only paper that does not require a university subscription to view. Please remember that ethanol failed to thrive in in the US in part due to lack of research. Research funds were cut off when ethanol became politically unpopular. Ethanol became politically unpopular after pundits with little understanding of science or engineering panned it.
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    Apr 18 2011: That sounds great Jason. How adaptable are your experimental systems to micro energy production? Will I and my neighbours, or a small co-operative for example , be able to access this technology (I'm talking about the liquid fuel here) and set up our own liquid woodgas 'plants' ? I'm very interested in the development of technologies, and of knowledge bases that allow people to produce energy locally , and to make and adapt energy pproduction units themselves, rather than always having to hand this over to centralised power bases.

    On the question of bio-char.... I want to experiment with this in the garden and on the allottment especially since there's no water and the South East of England is already (it's only April!) ina a state of semi drought). But apparently ordinary charcoal is treated in some way that would be harmful to the soil. How can I know which kind of charcoal to buy? (Will be making my own but need to get a shredder etc and not enough finance for that)
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      Apr 19 2011: Hi Anna, you can make your own charcoal for your garden using a wood stove with the damper on strong ( I used to keep a tiny little one burner one near my big garden)..you can also use the charcoal from your fireplace..or here in U.S. there is no a hardwood charcoal product that doesn't have any petro chemicals.I haven't seen any guidance on how much to use but I have found.it doesn't take that much..I used about 2lb/100 sq feet ( in a very rich organic soil).I use a hammer or stone to smash it into small marble size pieces soil at the bottom of the root level for the type of plant. Guidance says it should be finer but but I get good results with my ad hoc process. Good luck experimenting..you'll be happy and your allotment will be a wonder!!!.'
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      Apr 19 2011: Hi Anna,

      Yes, community-scale biochar + liquid fuel plants are very exciting. There are still some technical challenges to implementation, but I foresee Northern Latitudes being the ideal first markets. These regions have abundant wood waste, and a need for low-cost heating oil.

      I do not recommend using ordinary charcoal briquettes for agricultural amendment. Most charcoal briquettes in the west are made from treated wood, and are often impregnated with lighter fluid. However, if you can find a source of 'natural, lump hardwood charcoal' it could serve as a viable alternative until you can make your own. I'm not sure of availability in the UK, but Whole Foods in the US offers a viable product.
  • Apr 18 2011: Hallo Mr. Aramburu,
    Nice hypothesis. I just wonder what empirical evidence did you acquire under an african setting. Which soils and crops, respectively respond positively to charcoal burial. Would you compare the results with compost, fertilizers?
    Any side effects on the soil microflora on both beneficial microorganisms or soil-borne diseases? What are actually the sources of charcoal in the african countries and their costs? Is this technology addressing the smallholders or the large farms? You address the issue on a global perspective, I wonder whether you master any down-to-earth results?
    Wish you success and would appreciate an answer to the problem areas I put forward.
    Reuben Ausher
  • Apr 18 2011: We need to integrate biochar into American agriculture, just as much as it's needed in developing countries. Topsoil losses in the US since WWII are staggering. Biochar represents "new" means for the US to begin investing in its soils for present and future food productivity.
  • Apr 15 2011: I'm a little confused by the project, adding carbon to the soil is good, but like all soil amendments it has to be in balance with other soil minerals or the crops will not grow properly.

    Carbon sequestration in Ag soil is a biological function of microbes absorbing the CO2, not physical sequestration as when CO2 is pumped deep into the earth.

    I must be missing something about your product.
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      Apr 15 2011: George,

      Good questions. Biochar is a mineral form of carbon, so it is not absorbed or consumed by soil microbes (unlike organic carbon aka compost or humus). Biochar itself has few nutrients (nitrogen, phosphate etc). Instead, biochar acts as a soil amendment, meaning it actually improves the physical quality of the soil.

      When added to soil, biochar acts as a sponge-- it holds onto nutrients, water and microorganisms. By reducing leaching and concentrating nutrients, we find biochar can significantly improve crop yield.

      The carbon sequestration aspect is a bit unique-- biochar is made from waste that normally decomposes into CO2, methane etc. When it is converted to charcoal, the carbon in the ag waste is mineralized, meaning it can no longer be decomposed. Provided that charcoal stays in the soil and isn't burned, the carbon can remain sequestered for thousands of years.
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    Apr 14 2011: Well, just producing biochar to offset carbon emissions is possibly useful, but if biochar were already a bi-product of something else that reduced emissions, or saved energy somewhere?
    Last week I was introduced to the woodgas burner, James greyson style, made from tins and a kettle, and using woodchip from garden waste. James boiled three kettles worth of water on about a litre of woodchip in 15 mins.(about 20-30 cups of tea-worth I reckon), and if we'd had sausages we'd have been able to grill them on the hot coals left over. The remaining biochar he carefully stored away to put on the compost pile at home. (apparently charcoal stores nutrients during the composting process that would otherwise be leached out). the burner gave off no smoke, but plenty of heat. My favorite aspect of Jame's burner is that I could make it myself, and all parts are replaceable by popping down to any local restaurant/school and asking fora couple of tins they're throwing out anyway.
    I, along with most other garden owners, have wood waste that can be chipped for using in a woodgas burner and I reckon that it wouldn't take much to set up systems whereby local garden waste wood can be shreded, dried and used in woodgas burners that could supply heat to local schools, community buildings etc. It would save on carting the stuff away, and the resulting biochar could be given back to gardeners to put in their compost piles.
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      Apr 15 2011: Anna, there are several options to use the process heat or woodgas produced during pyrolysis (the process of making biochar). We have systems that can use this gas for cooking or boiling water. In fact, that's what we currently deploy in Kenya. We are also developing more advanced systems to capture this gas and convert it to a liquid fuel, but this is roughly 6 months- 1 year away from deployment.
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    Apr 14 2011: Jason..thanks for bringing your amazing work to TED Conversation..glad to see more time given. What do you tink the possibilities are for using charcoal enhancements in large scale agribusiness? Do you have any pilots planned to explore large scale agribusiness applications?
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      Apr 15 2011: Thanks Lindsay. Glad we have some more time to chat on this. There are definitely huge possibilities to bring biochar to agribusiness. Industrial ag (particularly organic ag in central California) is a massive consumer of water and nitrogen, as well as a huge point source emitter of carbon. Biochar equipment can definitely be scaled up to meet the needs of these large farms. Use of biochar would cut the water and fertilizer demands, while sequestering carbon. Right now, the big challenge is getting farmers to try out these new technologies, as they are notoriously conservative....
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        Apr 15 2011: Jason..what about crops that are produced at smaller scale tobegin with or with organic farmers who tend to have smaller operations. IFor crops I am thinking potatoes which in commercial production use so may herbicides and pesticides( no one would eat them if they knew)..from my own epxreience I know that the yeilds in potatoes with charcial ammendments is astonishing and also my potatoes are disease resistant..I never get blight. Also potatoes which have a huge mass of leafy greens and stalks might produce enough bio mass to be a point source of the material needed for bio char ammendments..( Or are you selling product not process???) Organic potato growers might be interested..there might be enough difference in yield and disease/blight resistence to make organic potatoes more competitive price wise with commercial ones. U Maine has a major ag department and we also have a really enlightened Maine Organic Farmer's Association to which all maine organic growers belong. Through Umaine a demo of some sort might be possible. Organic growers are a great first step for testing re:char feasibulity at a larger scale. My overall yields and disease, blight insect resistance has been dramatic since I strated using charcoal 4 years go.

        Another crop that might be a good target is artichokes. I get phenomenal yields here in Miane even since I started ammending my seafood based organic soils with charcoal. There again, the crp itself involves a huge amount of foliage and large stalks so the biochar might be selk generating at the site and in time a side business ( since once the charcoal reaches certain level no more is needed)

        No one who tries it will ever go back..that much I know.

        Of course I understand that the work you are doing now in Africa is critically important and your heart right now may be totally in winning suuport and help with that..and that is more than enough... may not be possible for a new company
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        May 6 2011: How about cotton growing Jason? Do you know of anyone who does this with biochar? I know nothing bout the growing side except that cotton cant be 'in it's element ' in conventional agriculture, given that so many pesticides etc (I believe) are needed to produce a decent yield, which suggests that the plants are under stress in these growing conditions.
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          May 9 2011: Interesting idea, Anna. I don't know offhand of any trials of biochar with cotton but I'm sure they will develop over the next few years. We are finding that soil type is more of a determinant of biochar's effectiveness than crop species. In general, acidic soils are most improved by biochar irrespective of crop.
  • Mar 31 2011: How do you produce charcoal without generating CO2?
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      Apr 15 2011: You generate some CO2 in the process of making the charcoal, but because you are using waste biomass there is no net emission.
  • Mar 30 2011: Clever and simple, but surely there isn't enough charcoal?
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      Apr 15 2011: There's not enough charcoal yet, but there are millions of tons of ag waste that are currently burned or left to decompose that could be converted to biochar.