transect points

I've added some photos to Flickr on how I currently prepare my charcoal for add ing to garden soil. This is in support of the Biochar for Gardeners FAQ.

I am lightly soaking (shallow soak, lots of turning to keep surfaces moist) my charcoal to precondition it for a crush-and-chop reduction and then screening. To soak, I add soluble mineral fertilizer and fish emulsion. Once in the soil, these will stimulate biologic conditioning and will help prevent stalled plant growth due to induced N deficiency, a concern with direct use of fresh char in the garden.

Also, regarding the mineral fertilizer, I have it in the back of my mind that adding ammonium sulphate (a common ingredient in off-the-shelf soluble fertilizer formulations) to the soak water will boost water penetration. I am thinking this might help because ammonium sulphate is used hold farm chemicals on waxy plant surfaces (like thistle), and because saltier water generally tends to penetrate further and faster into problem soils. I am encouraged to think that ammonium sulphate helps to overcome fresh charcoal's water repellency, even if only to a slight degree.

Note: Bio-char, agrichar, and charcoal are interchangeable terms when it comes to the intentional use of charcoal in the garden.

The argument for encouraging biochar use as a ubiquitous household practice is compelling: Improved garden soil will increase food production where it has the most impact on energy demand. Implementing charcoal manufacture at a household level draws in a supply of yard prunings and workbench scraps that otherwise would be lost to non-charcoal alternatives.

Unfortunately, finding even the most basic information on how to implement biochar use as a personal sustainability practice is discouragingly time consuming. In response I have started up a FAQ, a collaborative wiki, building on the efforts of the TP enthusiast community (1, 2, 3). Maybe you, the concerned gardening public, can help us thresh out the most important questions that need asking. Leave a comment here or at the FAQ. Here's my favorite bit from what has been posted so far:

2.05 What are some less smokey approaches to making charcoal for the gardener?

Choose your feedstock wisely. No matter what technique you use to make charcoal, choosing uniformly sized, dry woody material produces the highest yields. Uniformity is one reason that colliers will routinely use coppiced hardwoods.

Inverted Downdraft Gassification. For a cleaner burning configuration, consider a Top Lit Updraft (TLUD) technique, also referred to as an inverted downdraft gassification. The technique looks simple but in reality it involves some fairly sophisticated principles (PDF). That doesn't prevent success using common materials and dead simple design. Take that same open barrel configuration, tweak the design per the aforementioned sophisticated principles, and now light it from the top instead of the bottom. This takes a different skill set than lighting from the bottom but its also not that difficult to master. A little vaseline or ethanol on a cotton ball can work wonders for starting up. Once the fire gets going, the top layer of wood burns, creating charcoal, naturally. The heat from the top layer burning warms the wood below it releasing combustible and noncombustible gases which flow up into the charcoal layer. Glowingly hot charcoal has a wondrous ability to strip oxygen molecules from of anything that passes over it, so it converts the water into hydrogen, and the carbon dioxide into carbon monoxide. These two gases are flammable. They join with the other flammable gases released from the fuel. These ignite as they mix with air coming into the top of the open barrel above the charcoal layer. The result is a scrubbed gas-fed flame that is much more controlled, and which burns substantially cleaner and hotter than can be achieved with the bottom lit burn barrel. (Source). Insufficient oxygen below the combustion zone impedes loss of the charcoal despite the high temperature flame immediately above it. This allows charcoal to build up faster than it is consumed, at least until the pyrolysis zone reaches the bottom of the fuel column. The downside is that, while wondrously clean burning, a TLUD is challenged to achieve yields above 20% charcoal-to-fuel.

Folke Günther's simple TLUD-fired Retort. A retort works by restricting the air supply to the target feed stock for the duration of the burn. An outside heat source pyrolyzes the retort contents, small openings in the retort allow wood gas to escape, but restrict the flow of oxygen in. While retorts are capable of very high yield efficiency, the open flame used to fire the retort is not as clean as can be achieved with a gasifier. In small retorts, a further inefficiency is that wood gas generated from the retort can end up blowing by the combustion zone without being burned. Folke Günther's elegant solution is to combine a TLUD with a retort. This is easily the cleanest burning and highest yielding method we know of to make garden-sized batches of charcoal.

(Source)

I want to shout this from the rooftops.

A Win–Win–Win Scenario for Simultaneously Producing Bioenergy, Permanently Sequestering Carbon, while Improving Soil and Water Quality by David A. Laird, USDA-ARS, National Soil Tilth Laboratory

Processing biomass through a distributed network of fast pyrolyzers may be a sustainable platform for producing energy from biomass. Fast pyrolyzers thermally transform biomass into bio-oil, syngas, and charcoal. The syngas could provide the energy needs of the pyrolyzer. Bio-oil is an energy raw material (~17 MJ kg–1) that can be burned to generate heat or shipped to a refinery for processing into transportation fuels. Charcoal could also be used to generate energy; however, application of the charcoal co-product to soils may be key to sustainability. Application of charcoal to soils is hypothesized to increase bioavailable water, build soil organic matter, enhance nutrient cycling, lower bulk density, act as a liming agent, and reduce leaching of pesticides and nutrients to surface and ground water. The half-life of C in soil charcoal is in excess of 1000 yr. Hence, soil-applied charcoal will make both a lasting contribution to soil quality and C in the charcoal will be removed from the atmosphere and sequestered for millennia. Assuming the United States can annually produce 1.1 x 109 Mg of biomass from harvestable forest and crop lands, national implementation of The Charcoal Vision would generate enough bio-oil to displace 1.91 billion barrels of fossil fuel oil per year or about 25% of the current U.S. annual oil consumption. The combined C credit for fossil fuel displacement and permanent sequestration, 363 Tg per year, is 10% of the average annual U.S. emissions of CO2–C.

News and commentary on agrichar is flowing steadily this spring, first with the reporting on the 1st annual Agrichar Conference, and now with the reporting on initial agrichar trials by the New South Wales Department of Primary Industries (NSW DPI). Particularly encouraging is that the sophistication of the comments continues on the increase.

Snippets from ABC' Discovery channel ...

Recent greenhouse trials found soils mixed with the charred waste, called agrichar or biochar, were more attractive to worms and helpful microbes.

Agrichars trialled by NSW DPI include those from poultry litter, cattle feedlot waste as well as municipal green waste and paper mill sludge. Each agrichar has its own characteristics and interacts differently with different soil types.

Some agrichars raise soil pH at about one-third the rate of lime, raise calcium and reduce aluminium toxicity.

Kimber said more research needs to be done on working out which agrichars are best for which soils and on the impact of any contamination in biomass.

... reinforce the need for local pyrolysis pilot projects. The pyrolysis pilot hurdle is necessary where widespread agrichar use is the goal. Clean air concerns combines with the limited supply of local expertise and experience needed to achieve the low-temperature pyrolysis ideal for producing agrichar.

I have submitted comments emphasizing the need for pilot agrichar projects to our State's climate change folks.

(AP image source)

Two short articles well worth the read for terra preta enthusiasts:

Carbon project raises hopes: Waikato Times, NZ:

...Structural biologist Alfred Harris, process engineer Wolfgang Weinzetll and two Tauranga entrepreneurs are involved in Ecotechnology Ltd, which is working to reduce fertiliser use without hampering plant growth. The company is investigating producing a charcoal product from forestry and other organic waste which collects unwanted nutrients...

Recent work by Australian researchers showed wheat gained an additional $A96 per hectare in value when charcoal was banded in the soil with mineral fertilisers.

Is banded C the killerapp for agrichar? I don't know what the charcoal application rate was, but last I knew, banding equipment had limited material application capacity, charcoal is low density, and there was mineral fertilizer in the hopper also. A charcoal application rate in the neighborhood of about 100 lbs per acre seems reasonable to expect. At $100/ton for charcoal, material cost would be $5/acre ($A15/hectare). Is the value in comparison to a no-C comparison? I would surely like to see the research.

Seeder image source: Flickr by IRRI Images

Another May 15 article

Special Report: Inspired by Ancient Amazonians, a Plan to Convert Trash into Environmental Treasure (by Scientific American) has a great soil point-counterpoint under the heading: But is it viable? :

As with all new technologies, many questions about the ultimate utility of agrichar have yet to be answered. "As of now agrichar is not a uniform product," explains John Kimble, a retired USDA soil scientist. "And there's no easy way for farmers to apply it with existing equipment. They also need to know there is a large enough source of the material. Farmers are driven by profit, as is everyone, and they need to be shown that it will improve their bottom line."

Complicating debates about the costs of agrichar is the paucity of data on the subject. "No one is sure what types of biomass should be used as raw material," Kimble notes, "or exactly what production methods work best, so calculating the costs is really an exercise in speculation."

In addition, scientists are finding it hard to replicate the original terra preta soils. "The secret of the terra preta is not only applying charcoal and chicken manure—there must be something else," says Bruno Glaser, a soil scientist at Bayreuth University in Germany. Field trials in Amazonia using charcoal with compost or chicken manure find that crop yields decline after the third or fourth harvest. "If you use terra preta you have sustaining yields more or less constantly year after year," he says.

"I'm skeptical about adding just a pure carbon source," says Stanley Buol, a professor emeritus from the Department of Soil Science at North Carolina State University's College of Agriculture and Life Sciences who spent 35 years studying Amazonian soils. "It will be black and look good," but will it contain enough inorganic ions, such as phosphorus and nitrogen, essential to plant growth?"

Many of the interactions between the char, the soil and the microorganisms that develop with time and lend the soil its richness and stability are still poorly understood. Glaser believes that the key to making agrichar behave like terra preta lies in the biological behavior of the original Amazonian dark earths—a difference he attributes to their age. "You would need 50 or 100 years to get a similar combination between the stable charcoal and the ingredients," he cautions.

"I think [research into the biological behavior of terra preta] is where the new frontier will be," Lehmann counters. If he is right, and scientists can perfect a modern-day recipe for agrichar, then its fans will not need Richard Branson's $25 million to jump-start their initiative—the annual demand for fertilizers exceeds 150 million tons worldwide.

There are strong indications that soils amended with high (multiple tons/acre) rates of biochar need considerable time to reach their optimum. For setting where return on investment cycles need to be short, lower rates sustained for long periods of time may make more sense as a strategy for building soil C.

In a post earlier today: Mental Rut, Back40 takes Johannes Lehmann, soil scientist, and terra preta front man, to serious task for cheer leading the politically attractive aspects of TP:

Agrichar should not be crufted up with political baggage or tainted by association with the various climate hysteria inspired carbon wheezes. That it sequesters carbon in a more durable form than forests or other organic forms is a plus, but not its primary value. It is just one of the multiple benefits of agrichar. That fact should not be lost in a blaze of hype. It's the wrong message.

Back40's comments make good sense. Consider that terra preta has serious political problems in the offing. Charcoal production as a tool to combat global warming can be understandably counterintuitive. Char's mode of action in the soil is only partly understood, the degree of benefit to the soil is not well documented. Claimed char additions may be difficult to monitor.

Various blog and forum posts ask: Does the fuel value of charcoal provide a dangerous incentive to divert agrichar to fuel use? To overharvest biomass? Can the reality of terra preta nova be separated from marketing pitches by commercial pyrolysis interests?

In this environment, poor marketing choices will hurt the prospects of terra preta. We terra preta advocates need to distinguish our advocacy for improved soil from our advocacy of commercial pyrolysis and of char carbon sequestration. The value of char as a soil amendment can, and must, stand on its own merits. Only successful implementation of terra preta nova in stand alone and market driven settings can validate the fundamental benefits of biochar.

The agricultural value of charcoal is competing well with its fuel value at a market price of about $100/ton. Agrichar doesn't appear to need carbon sequestration subsidies, and at $4 a metric ton CO2, maybe it isn't even worth the paperwork.

Charcoal is fairly simple, and generally profitable to produce. The pyrolysis process used to produce char is adaptable and scalable. It can be used to co-generate heat, nitrogen fertilizer, hydrogen fuel and/or electrical power, indicating ample incentives to increase charcoal supply capacity. Rising fuel prices seem certain to increase the supply of charcoal.

The price of charcoal is driven mostly by its value as fuel. Coke, originally derived from coal to replace charcoal, cost about $100/ton in late 2006, which seems to also be about the same price as charcoal at the time. Significant quantities of charcoal are used in Japan for agriculture at these market prices.

Proponents of terra preta hope to speed adoption by subsidizing it with carbon credits. Currently CO2 sequestering goes for about $4 per metric ton on the carbon credit market. Carbon dioxide units at full molecular weight can be converted into carbon units by dividing by 44/12 (see endnotes here). Thus the carbon credit value of amending soil with charcoal is currently $14.67 per metric ton, or $13.31 per ton. This could be a nice kicker but the soil amendment value of charcoal, at $100/ton, is the significant component.

Note: Image from Flickr by carlosjwj (Location: Korogocho, Nairobe)

The techniques of ancient American Indians who used charcoal in their soil to keep them fertile (Terra preta) are being married with modern engineering. More here:
http://forums.hypography.com/terra-preta.html http://terrapreta.bioenergylists.org/



read more | digg story

Added: I came across this story on digg and noticed the blog-it tab...

Agri-char aka bio-char is the key ingredient in soil scientists' holy grail, terra preta nova (my previous mention). Initial reports from participants at the first meeting of the International Agrichar Initiative indicate continued hope that agrichar amended soils could contribute significantly to our planet's health and productivity.

Kelpie Wilson, Truthout's environment editor, writes:

Charcoal's pores also make excellent habitat for a variety of soil microorganisms and fungi. Think of a coral reef that provides structure and habitat for a bewildering variety of marine species. Charcoal is like a reef on a micro-scale.

Over at the Sydney Peak Oil forum, attendee burko writes:

It would be very easy to become enthusiastic about the future of these integrated technologies. However, there is one overriding impression of this field to keep in mind – it is brand, spanking new. So new that even the choice of name Agrichar is being debated. There are no books; there are few years of experience even amongst the researchers; the debates about the benefits to AGW are only just beginning.

In short, being a part of the conference could be compared to hearing an orchestra tuning up. There are skillful cellists and masterful tuba players preparing next to each other. The idea is potential for beautiful music, rather than cacophony. We aren't really sure who the conductor is yet – plenty of skillful people are taking part of that role. There is cooperation and the desire to share experience at all points – but this is a new kind of orchestra.

While the soil biology alone is a staggering subject, we should be as interested in the methods of producing the black carbon. Burko writes on pyrolysis:

The gas produced is referred to as syn gas, called producer gas sometimes.

My formative understanding of the process says something like this – if you want to produce non-activated chars, temperatures need to be constrained below the levels that gasification requires in order to make the reaction sufficiently exothermic to be self sustaining.

Of course, there is more to it than that – I did find that combustion engineers found it difficult to provide a simpler explanation.

I did get one useful figure from Dr Robert Brown, from Iowa State University – if you're burning wood in an open fire, you're probably only getting a third of the heat energy that should be possible from gasification – a pretty compelling reason to try and understand this stuff. It's been said that up to a third of the worlds deforestation happens in the name of inefficient cooking fires.

From the reports, it is clear that the number of players, and their diversity, is growing exponentially. One reason for this diversity is that the process of making terra preta nova appears to be as adaptable to a wide range of soils and climates as it is scalable. You can have regional collection and distribution approaches coexisting with processes adapted to individual enterprises. The plan at Fourth Corner Nurseries (mentioned previously) near Bellingham, WA is a great example of both points. The operation already amends the soil with char. Observed better root growth confirms what we already sense, that black carbon can have a positive effect on a wide range of soils. The nursery plan to use surplus biomass from their willow coppice field to power the nursery and to produce char is easier said than done, but is brimming with promise.

Image: Scanning electron micrograph of a conductive carbon sticky tab. (Flickr - St Stev)

The Hypography Science Forum has upgraded the terra preta discussion from a long, 43 page thread to a forum, with separate threads for charcoal making, gardening experiences, news, etc. The new location is here.

A recent message posted to the forum, from Janice Thies, Cornell University, is most interesting:

I am extremely heartened by the very positive response to the idea of using of biochar in agriculture and horticulture and appreciate your desires to put it to immediate beneficial use in these systems.

My name is Janice Thies. I am a soil microbial ecologist. I have been working with Johannes Lehmann at Cornell University for the past 6 years on various aspects of terra preta (microbial ecology in its natural state) and agrichar (how microbial populations respond to adding biochar to soil). It took us three years to convince the National Science Foundation that we were on to something here and to obtain funding for some of the basic research that is necessary for us to provide the data needed to answer your questions with confidence. Hence, we are several years behind where we could have been if funding had been available earlier. Even now, we continue to seek support for doing the types of tests many of you are most interested in. The results of our NSF funded research are just now being published or written up, but we are still a long way from being able to answer everything.

Currently, there are 10 research laboratories around the world that are testing char made from bamboo that was prepared at 5 different temperatures in the range we believe is likely to provide char that will be most beneficial for both plant production and C sequestration purposes. Rob Flannigan prepared the char in China and has engaged us all to do a wide range of testing on it. So, we should have some news about what temperature range might be best reasonably soon, but it is still early days.

Bio-char amended plots respond more favorably if adequate nitrogen fertilizer is provided. This is consistent with a previous observation here that added nitrogen is desirable when increasing soil microbial biomass.

One of the reasons that Dr. Lehmann recommends caution in the use of biochar can be seen in the paper recently published by Christoph Steiner et al., mentioned in previous messages. He did get excellent plant growth responses to adding biochar - as long as mineral fertilizer was also used. When you look at plant growth in the biochar only treatment, growth was worse than doing nothing at all (check plots). In the nutrient-poor and highly leached soils of the tropics, the added biochar likely bound whatever nutrients were present in the soil solution and these became unavailable for plant uptake. These results should make you cautious as well. How fertile a soil needs to be for biochar not to reduce plant growth or exactly how much fertilizer and/or compost should be added to be sure there is good, sustained release of nutrients, will likely vary soil to soil and we simply do not have these data available at present to make proper recommendations. So, keep this in mind as you do your own trials with your own soils or mixes. Try to follow good design practices for your trials, with replicates, so that you can judge for yourself what amount and type of biochar works best in combination with what amounts and types of fertilizers or composts you use (depending on the philosophy behind your cultural practices).

The soil microbial community in terra preta is different from that of surrounding soils, yet is repeatable over great distances. Actinomycetes bacteria seem to have a particular affinity for terra preta.

As to the 'wee beasties' or 'critters' as I like to call them, we have made progress on this front over the last several years. Brendan O'Neill and Julie Grossman in my laboratory, Sui Mai Tsai, our Brazilian collaborator at CENA and the University of Sao Paulo, and Biqing Liang, and many others in Johannes Lehmann's laboratory have been characterizing microbial populations in three different terra preta soils and comparing these to the adjacent, unmodified soils near by to them. Brendan found that populations of culturable bacteria and fungi are higher in the terra preta soils, as compared to the unmodified soils, in all cases. Yet, Biqing found that the respiratory activity of these populations is lower (see Liang et al., 2006), even when fresh organic matter is added. This alone means that the turnover of organic matter is slower in the terra preta soils - suggesting that the presence of black C in the terra pretas is helping to stabilize labile organic matter and is itself not turning over in the short term. All good news for C sequestration. However, since the respiratory activity is lower (slower decomposition), this may lead to slower release of other mineral nutrient associated with the fresh organic inputs. In some circumstances this is a good thing (maintaining nutrient release over the growing season), in other circumstances (more immobilization), perhaps not. We need more work on this to understand the implications of these results more fully.

Julie Grossman, Brendan O'Neill, Lauren McPhillips and Dr. Tsai have all been working on the molecular ecology of these soils along with me. So far, what we know is that both bacterial and fungal communities differ strongly between the terra pretas and the unmodified soils, but that the populations are similar between the terra preta soils. These results are both interesting and encouraging. First, that the terra preta soils (sampled from sites many kilometers apart) are more similar to each other than to their closest unmodified soil (sampled within 500 m) tells us that the conditions in the terra pretas encourage the colonization of these soils by similar groups of organisms that are adapted them. Our group has been working on cloning and sequencing both isolates from the terra preta soils and DNA extracted directly from them. A number of bacteria that were isolated only from the terra preta soils are related to the actinomycetes, but have not yet been described yet and are not very closely related to other sequences of known organisms in the public genetic databases. This is also very interesting. Some of you will know that actinomycetes have many unusual metabolic capabilities and can degrade a very wide range of substrates. Also, many are thermophilic and play important roles in the composting process. We have yet to fully characterize these organisms, but are optimistic that in time we can make some recommendations about what organisms or combinations of organisms might make a good inoculant for container-based biochar use. Two papers describing these results are in their final editing stages and will be submitted for publication in the journal 'Microbial Ecology' within the next few weeks. So, keep an eye out for them in several months time.

The prospect that glomalin might play an important role in terra preta needs to be approached with caution.

I want to add a word of caution about getting too excited about glomalin. Another of my students, Daniel Clune, has been working on this topic and his work suggests that the glycoprotein referred to as 'glomalin' in the literature - operationally defined as the protein extractable in a citrate buffer with repeated autoclaving - is not what it has been purported to be. First, the proteins extractable by this method are from a wide range of sources, not just arbuscular mycorrhizal fungi. Second, it has a shorter turnover time than has been suggested. Third, in a test with hundreds of samples taken from field trials varying in age from 7 to 12 to 34 years, its relationship with aggregate stability is suggestive at best. Dan's work is also being written up right now and should also be submitted for publication soon.

Could archaea be important?

Some field trials with bamboo char have been conducted in China, with very positive results. Look for upcoming papers from Dr. Zheng of the Bamboo Institute in Hangzhou. Another student in my laboratory, Hongyan Jin, is working with the soils from this experiment to characterize the abundance, activity and diversity of the soil bacteria and archaea. Her first results will be presented at the upcoming conference on Agrichar to be held in Terrigal, NSW, Australia, at the end of April/beginning of May this year. Please be sure to see her poster should you attend this conference.

Janice's recipe for char based potting soil:

Lastly, from my personal gardening experiences, I use spent charcoal from the filters of the 14 aquaria I maintain for my viewing pleasure. I combine it as about 5% of my mix with 65% peat moss, 10% vermicompost (from my worm bin in my basement where I compost all my household kitchen waste - aged and stabilized, not fresh!), 5-10% leaf mulch (composted on my leafy property in NY), 5-7% perlite to increase drainage, decrease bulk density and improve water retention and percolation, and some bone meal and blood meal (to taste :-) ). This makes an excellent potting mix for my indoor 'forest'. I am very much still playing around with this.

I hope this very long posting helps those of you feeling frustrated and wanting answers. Many labs are working on many fronts, but it is early days and we are trying to answer some fundamental questions first and then use the information to guide our field tests and recommendations.

I hope to meet some of you at the Agrichar Conference (see details at the conference website) http://www.iaiconference.org/images/IAI_brochure_5.pdf
The Cornell work and that of many of our colleagues in Brazil, China, the US, Australia and elsewhere will be presented, along with that of many others actively working on agrichar production and use around the world.

Good luck with your own testing and kind regards,

Janice Thies - jet25 at cornell.edu
719 Bradfield Hall, Ithaca, NY 14853

Technorati Tags: terra preta archaea bacteria soil microbiology bio-char garden glomalin

Richard Haard, Fourth Corner Nurseries, near Bellingham WA is using charcoal as a soil additive, apparently for at least the 2006 growing season. From the way he describes it, this bare-root nursery operation seems like one of the better places to see if and how much of a difference charcoal can make. He has lots of pictures of the process, including some observed positive effects on root growth. He is using charcoal as a carrier for inoculate as a matter of routine and has several future experiments under consideration:

• Rehabilitation of depleted soil: Bare-root production at the nursery is very hard on the soil and impact varies with the species grown, as revealed by differences in subsequent cover crop vigor. Using charcoal treatment plots and comparable control plots would be interesting.
• Improving nodule formation on Alnus rubra roots: Using charcoal to enhance performance of Frankia sp., an Alnus root nodule endophyte.
• Natural inoculation of bromide sterilized soil: Using a combination of charcoal, fertilizer and natural inoculum in an attempt to reverse stunting apparently due to soil sterilization.

As an aside, he mentions that the "use of surplus biomass from our willow coppice field and other materials is our alternative energy vision."

Yes.



Technorati tags: bio-char, terra preta

Charcoal holds a key to improved soil vitality. Reported effects are impressive. Level of response varies with the temperature the charcoal is produced at. Low temperature charcoal is better. The soil improvement process that charcoal initiates is poorly understood. I want to see this at work for myself.

Briquets are no good for my experimental use. They are made with a high-boron binder, and the temperatures that are used to produce them leave few wood gas condensates. At some point I'll find a supply or locate a collier. In the meantime I'm making my own, just to see what it takes.

I made a few small batches of low-temp charcoal with a retort fashioned from a cracker tin. It produced impressive volumes of smoke, so I got on a track of finding out how that smoke might be put to good use.

Thomas B. Reed, Biomass Energy Foundation president and CREST gasification list moderator, has been working on a better understanding of inverted downdraft gasification. He is passionate about improving the efficiency of cook stove fuel use in third world countries. Thus his perennial effort to perfect a household-size inverted downdraft gasifier. Of interest to soil scientists, some of his designs have the capacity to produce charcoal.

Tom Reed designs have inspired others. In 2003 Ray Garlington produced a simplified design. I modified Ray's design to be able to shut it down and hold the charcoal. I used it to boil a cup of water with only a small handful of cedar. It was 2 deg F outside but not a problem. I even produced a fair bit of charcoal. Photos of my run are posted on Flickr.

Update: Concise description of the process: "The wood is placed into the stove and ignited from the top. The top layer of wood burns, creating charcoal. The heat from the charcoal layer burning heats the wood below it, and ignites it. The gases (carbon dioxide and water) flow through the charcoal layer. Glowing hot carbon has a unique ability to strip oxygen molecules off of anything that it touches, so it converts the water into hydrogen, and the carbon dioxide into carbon monoxide. These two gases are flammable and they are ignited once mixed with air above the charcoal layer. The result is a flame that is much more controlled, and cleaner than that of raw wood burning." (Source)

The Godfather of Terra Preta, soil scientist Wim Sombroek (1934 - 2003) enjoyed a lifelong fascination with enhanced soil. The importance of plaggen soil in his native Netherlands impressed him at an early age, and early in the 1960's, he recognized in the Amazonian Dark Earths something familiar and precious. Before his passing, he assembled specific soil scientists, challenging them to discover the process for making and sustaining a modern equivalent of the bio-char enhanced terra preta, what he termed terra preta nova.

A great opportunity in answering Sombroek's challenge lies is surmounting the opacity of mutualistic rhizospheric species to traditional analytical approaches: only 1% of rhizospheric species are cultureable ala petri dish. We don't have a robust body of culture-independent studies against which to compare Terra Preta, so we are doubly challenged to reverse-engineer the phenomenon.

Considering Wim Somboek's many noteworthy accomplishments, the perspective of his international leadership, and the late-in-life timing of his challenge, one senses he is pointing us to a mystery fundamental to understanding soil in new and exciting ways. This happens at a time when the soil science profession is in dynamic transition and sorely in need of a unifying vision. Wim Sombroek has given soil scientists a most welcome and worthy quest.

Peak Energy has a long post on Terra Preta that brings together what has been established on the subject. As of yet, there is no direct mention of the role of glomalin , just a minor mention of the mutualistic fungi that produce it. Glomalin is an unvalidated factor in Terra Preta formation that several of us sense will be demonstrated by soil research as fundamentally important.

Spurred on by back40, I am fascinated with bio-char, Terra Preta's key soil amendment. Last summer I constructed a small charcoal retort out of a cracker tin. I used it to produce small pilot batches of low temperature charcoal. Hoping to transform my simple charcoal into a reasonably bio-char-like material, I am currently composting my bits.

Image source: Nestor Kaempf

Andrew Rates (UWA) has started a blog for UWA's caffeine-dependent Soil Science Journal Club. It is a closed forum, intended for "UWA Higher Degree by Research students and UWA staff only." This is the type of idea that we could see perpetuating similar efforts at other schools and research groups.

The idea of this blog is to record the progress of a journal club, and preferably to provide an ongoing resource for people interested in recent advances in Soil Science and related disciplines.

I have in mind running a Journal Club for interested postgraduate students and staff. I would like to focus on recent significant advances and developments in Soil Science, preferably including all subdisciplines (soil biology, soil chemistry, soil physics, pedology, ...).

Articles are likely to be sourced predominantly from premier / high-impact journals such as Science, Nature, Trends in Ecology and Evolution, Earth and Planetary Science Reviews, etc. This isn't to say that we can't access the more traditional soils journals, but I'd like (at least at first) to focus on big-picture, high-impact issues.

There is a promising post here of the group's first discussion subject: Marris, E. 2006. Putting the carbon back: Black is the new green. Nature 442:624-626 . It seems to me these folks are asking the right questions.

I have added this site to my (frightfully short) list of soil science blogs.

From TroutGrrrl @ Science and Sarcasm:

The Smithsonian Institution, the Soil Science Society of America (SSSA), and others are planning a 5,000 square foot soil exhibit at the National Museum of Natural History in Washington, D.C. The projected opening for the “Soils:Worlds Underfoot,” exhibit, is 2008. The exhibit will occupy one entire hall of the museum and will be displayed for 1.5 years. It will feature state soil monoliths and interactive soil displays. Each of the 50 states and three U.S. territories will donate a monolith of their state soil for the display. A separate mobile exhibit will travel to hundreds of museums, schools, and libraries with soil education kits, web-based activities, curriculum, and career information.

The exhibit is expected to require 2+ years for the Smithsonian to design, build and install. Sponsored by the SSSA, the final decision about exhibit building, design, and content rests with the host: Smithsonian's National Museum of Natural History. The total cost is projected to be $4 million.

The exhibit will emphasize the living, biological nature of soils, the variation in soils from one region or locality to another, the dynamic nature of soil, the role soil plays in linking the earth's air, land and water resources, and the importance of taking care of our non-renewable soil resources.

This exhibit is welcomed with enthusiasm by soil scientists. It would be at any time, but now, when soil science is at the cross roads and with soil scientists keyed up about the profession, it is even more so.

Many soil scientists are asking if the profession can survive another generation. Soil science departments continue to close up shop, as they have been for 20 years. Soil science is being dismembered and parts allocated to engineering or agricultural disciplines. Retiring soil scientists in academe are not being replaced. USDA-NRCS soil scientist hiring is essentially frozen despite the fact that NRCS does not have the manpower to fulfill its soil mapping commitments. Without soil science graduates, and without jobs to attract them, my profession appears doomed. SSSA membership growth has leveled off, and reversed in 2005. SSSA Journal publishing revenues are under assault by the growing movement toward open access, depriving SSSA of revenues needed to combat the trend.

It may surprise some that I believe our profession is very healthy and is experiencing a most welcome transition. Soil scientists working for the federal government, agriculture or academe may be looking at a shrinking pool, but try to find a consulting soil scientist outside of these areas that is not working 50 and 60 and more hours a week.

Look at the fundamental need for the science. Recent discoveries about microbial diversity, glomalin and amazonian dark earth have occurred at a time when carbon sequestration (pdf), atmospheric CO2 fertilization effects and climate change have reminded folks that the complex role of soils is too important for reliance on second-hand information, simplistic models and large scale county soil map data. We need the soil scientists themselves, not just their research papers and their maps.

Open-access (OA) to published scientific articles may threaten our scientific institutions, but is healthy for the sciences and the individual scientists. OA opens up participation to a much larger scientific community, gaining more dynamic interaction and collegiality than it loses in the area of peer-review. Researchers are attracted to publish open access because OA papers are cited more than restricted access papers. Open access to research data will do more to prevent the recent rash of scientific misconduct than peer review alone can accomplish and at essentially no cost. Replacing peer-review with review-by-many looks increasingly workable. Supporters note that Watson and Crick's paper on the structure of DNA was published without the benefit peer-review.

The soil science licensing phenomenon continues to grow within the United States. The movement is now well established at a state level. Growth is mostly because of a pattern of septic system failure due to poorly understood soil dynamics. The growth of soil science licensing is in step with insurance premium growth for Health Districts to cover their septic system failures. Regions with the most failure have the most enthusiasm for licensing.

Whereas membership in the SSSA has peaked for now, membership growth in the National Society of Consulting Soil Scientists is growing steadily. Job offers for soil scientist positions with private sector environmental consulting firms and health districts now surpass job opportunities in agriculture, academe or the federal government. This indicates a healthy recognition of the role of soil science in dealing with all sustainable land use issues, not just those involving agriculture, range and forestry.

This is a time of great change for the profession, and great opportunity to advance the science.

Tech Tags: soil science

Most states have recognized official soils. Georgia may be the first in designating an official state dirt:

HB 1443 - Red clay; Georgia's official dirt; designate

A BILL to be entitled an Act to amend Article 3 of Chapter 3 of Title 50 of the Official Code of Georgia Annotated, relating to state symbols, so as to designate Georgia red clay as Georgia's official dirt; to repeal conflicting laws; and for other purposes.

It is tempting to poke fun at this diversion but many others (Improbable Research, No1ofConsequence and Scribal Terror.), all faster on the draw than me, have already developed this fertile territory.

Let me instead point out the obvious positives, if this passes. First, no taxes will be increased. Second, no rights will be diminished. Third, no pockets will be lined. In any state, not just Georgia, any one of these legislative feats is a noteworthy accomplishment. Fourth, it is an opportunity to engage in self-deprecating humour, which, in my opinion is one of the essential ingredients for preserving mental health. That Georgia would do this greatly increases my confidence in this legislative body.

Before I give my fifth reason, I offer these excerpts describing red clay:

"I curse the red clay,'' says Santiago. "They have it in Florida but it's not as bad. And I've been to Texas with the [baseball] teams I've worked with but it's not as bad as anything around here.'' Other parts of the country do have red clay. But it dominates the landscape of no other region as it does the Piedmont, that rolling plain between the mountains and the sea - extending from Alabama to New York.

"It is a striking fact of the landscape,'' says Al Stuart, professor of geography at UNC Charlotte.

It is even more than that.

Red clay is the ground of our being, the material that has shaped, nurtured and sustained us. So different from the dark gumbo soil of the Mississippi Delta or the yellow sands of the Carolinas coast, it has produced crops, provided building material for schools, houses, churches and factories and shaped our sense of ourselves in ways large and small.

Embedded in our history, it is the soil "as red as blood'' described by John Lawson, who in 1700 was one of the first Europeans to explore the land; the stuff Catawba Indian women fashioned into their distinctive stamped pottery; the material spit from the wheels of the first race drivers' cars on the sport's earliest dirt tracks; gluey enough when wet to pull the shoe off your foot.

Thomas Wolfe's character Oliver Gant takes a train from Pennsylvania to Altamont, Wolfe's fictionalized hometown of Asheville. Gant stares out from the train window at "the fallow unworked earth, the great raw lift of the Piedmont, the muddy red clay roads and the slattern people.'' The novelist drew a parallel between the raw land and the untidy people, seeing the prospects dim for each. But Wolfe was wrong.

The Piedmont became prosperous, an ironic result of the poor growing qualities of red clay. "Because the soil wasn't very forgiving there's always been a sense among Piedmonters that we had to try harder ..."

In some places it goes down 100 feet before bedrock. Geologists and soil experts call it an "ultisol,'' soil formed over billions of years.

Piedmont red clay truly deserves to be recognized as the implacable force that it is. A state government seems like the perfect size jurisdiction to act on this responsibility. Thank you Georgia.

Side note. Georgia red clay soil characteristics have quite a bit in common with Amazonian oxisols and ultisols. They are acidic and low in fertility. The Piedmont soils in Georgia would benefit from a innovative Amazonian soil ammendment, bio-char, mentioned earlier. It is fortuitous that Eprida, a biomass processing concern, has its bio-char pilot plant in Georgia.

Tech Tags: politics legislation soil science terra_preta bio-char

The scientific mystery of the Amazonian anthropogenic dark earth (anthrosols) referred to variously in Portuguese as Terra Mulata and Terra Preta do Indio (Indian Dark Earth) is closer to being solved. The intricate recipe used for producing these fertile soils has been the object of longstanding scientific curiosity.

An important factor, highlighted in the latest news release on the subject, is the use of slash-and-char techniques versus slash-and-burn:

Whereas slash-and-burn methods use open fires to reduce biomass to ash, slash-and-char uses low-intensity smoldering fires covered with dirt and straw, for example, which partially exclude oxygen.

[Update: Back40 (Muck and Mystery) pulls in some quite interesting notes and comments on soil+char.]

Tech Tags: soil science research