Tuesday, February 27, 2007

Hypography Science Forum Upgrades Terra Preta Discussion

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

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Sunday, February 25, 2007

Soil Collapse Conditions Illegal, Preventable

In the previous post, Don't Dig Too Deep, I wrote of the alarming extent of death and injury related to soil collapse. Historically there have been 100-300 deaths a year in the US due to soil collapse. One would hope that the current level is far lower, since these deaths are preventable, and the conditions that cause them are largely illegal to send workers into. News coverage of trench collapse is often cavalier when it reports survival, celebrating a can-do attitude and sidestepping a duty to inform. News readers deserve to be told how extensive the problem is, industry standards, or how they can take simple steps to avoid future injury to themselves and their loved ones.

Injuries that occur in the workplace deserve to be covered in the news from the point of view of compliance and employer ethics. All news coverage I have ever seen on these tragic work-related events leave off the preventable and illegal aspects of the event. The story in Georgia that prompted my post was no different.

Jordan Barab has been posting on this issue with the news media: trench collapse should not be treated this lightly; most workers do not come out alive.

Soil collapse is quiet and quick. Soil goes from supported to free fall in an instant. A collapse event initiates with little or no warning to a trench occupant. It is loudest at the end of the collapse event, yet seldom heard beyond the immediate area of the trench. Unless it is witnessed directly, or the victim can make themselves heard, a rising cloud of dust is the only evidence available to alert coworkers to respond.

A discrete soil collapse event is normally progressive in nature. First an uppermost portion of a trench wall caves off, and drops straight down like a slice off a block. When I am in a trench, even a shallow one, I am ever vigilant for this first increment. Falling from the maximum height it is moving fairly fast by the time it reaches the trench bottom. In injury events, it typically traps the feet and prevents trench egress. The collapse progresses to involve soil volumes coming from further down the wall and further back: lower velocity but far more weight and volume than the first increment. The progression commonly ends with a maximum increment.

This leaves remaining vertical wall sections unsupported at the margins of the collapse. Subsequent collapse of these vertical sections is a substantial hazard for rescue workers. 60 percent of fatalities in trench rescues involve would-be rescuers.

OSHA standards require trenches deeper than 5 feet to be shored. Shallower trenches can still be the site of fatal soil collapse, especially if workers are not standing upright. Movable temporary shoring is available within the construction industry. An alternative is to excavate sloping or terraced sidewalls. Due to vibration, heavy equipment should not be left running in proximity to occupied trenches. Interior trench corners are particularly susceptible to collapse and deserve particular caution.

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Don't Dig Too Deep

Historically, there have been between 100 and 300 people killed in the United States every year due to trench collapses. Jordan Barab covers these trench hazards in his worker safety blog, Confined Space.

On Friday, a worker in Georgia was trapped for two hours, briefly up to his neck, when the trench he was working in collapsed. Last word was that he survived, but the extent of his internal injuries had not been assessed. He is in my prayers.

It is a strong man, and lucky to boot, able to breathe under the crushing dead weight of soil. When soil drops, it quickly gains sufficient momentum to slam the air out of most folks. Against the weight of soil, there can be no place to expand the lungs.
Even a person buried below his chest may still be grave danger. Where the soil reaches the diaphragm level, and settles in a form that has pushed the abdominal contents into the chest cavity, the effect on breathing can be the same as confining the chest.

Soil walls may collapse multiple times, or in phases, in the same trench. 60 percent of fatalities in trench rescues involve would-be rescuers. Soil collapse related deaths are both work-related and recreation-related, and all too often include children. The beach is a repeated setting of concern (from a story apparently no longer up at WebMD):

Safety Note for Beachcombers: Don't Dig Too Deep

Sand Holes Collapse, Suffocate Toddlers, Children, Even Adults

By Jeanie Davis
WebMD Medical News

Reviewed by Dr. Jacqueline Brooks

April 17, 2001 -- Sharks, skin cancer, drowning -- was a day at the beach ever a picnic? What's left, just digging holes in the sand? Maybe not. With beach season drawing nearer, two researchers report that several children -- and young adults -- have died when sand holes got a bit too deep and suddenly collapsed on them.

“There actually is the potential for catastrophe," says Bradley A. Maron, a second-year medical student at Brown University School of Medicine in Providence, R.I. The paper, which he co-authored with his father, Barry J. Maron, MD, of the Minneapolis Heart Institute Foundation, appears in this week's Journal of the American Medical Association.

In their paper, the Marons document seven cases of sudden- and near-death experiences involving beach holes.

The Marons' study began four years ago -- during a vacation at Martha's Vineyard -- when they witnessed a beach-hole incident that triggered their study of the phenomenon. "It was an 8-year-old girl, under the sand for seven minutes before rescuers could get to her," he tells WebMD. She survived, says the younger Maron.

He spoke with the beach rescue team afterward: "They said without question it seems to happen with greater frequency than is realized," Maron tells WebMD. He began watching CNN for similar news accounts and made follow-up phone calls for details.

Six of the seven incidents he documented since 1997 took place on public beaches -- all on the Atlantic coast -- mostly involving children, says Maron. In five cases, the holes were being dug by hand or using toy beach shovels. In two instances, people were inside holes they had found.

In each instance, Maron says, the person suddenly became completely submerged by sand when the walls of the excavation unexpectedly collapsed.

"The biggest complication in rescue efforts," Maron tells WebMD, "is that the sand appears undisturbed after the hole caves in, so rescuers don't know exactly where the person is. And they have to dig with their hands, for fear of hurting them with shovels. They just can't get to them in time." Four people among the cases were submerged for long periods of time -- 15 minutes to an hour -- and could not be resuscitated.

In one case, a 21-year-old man vacationing in North Carolina dug a nine-foot-deep hole. "He was down in the hole, just lounging in the chair when suddenly and unexpectedly it collapsed on him," says Maron. "It was catastrophic immediately. He had to be removed by bulldozer." Rescuers attempted CPR, but the man died.

Three people survived -- including one who experienced hypothermia and shock -- after lifeguards or other bystanders frantically dug an air pocket around their mouths and noses.

"Parents feel safe with their kids right by their side," Maron tells WebMD. "But they may not be attuned to what's going on. And afterward, people are so shameful of themselves. Of course it's not their fault; it's an accident, but it's absolutely preventable. It just takes common sense."

This phenomenon was news to at least one beach rescue team member, but he's not surprised.

"A lot of times you see kids digging up to waist deep, and that can be just as hazardous as head-deep," says Sean Gibson, a paramedic with New Hanover Regional Medical Center, which services the beaches in Wilmington, N.C.

"A cubic foot of sand weighs much more than you would think, and there's no way that child could get out," he tells WebMD. "And nobody would be able to hear that child either."

Adults should know better than to take the risk, says Gibson. And parents should be watching their children more closely. But if children do get into this situation, here's good news. "With toddlers and children, you should be able to get to them fairly quickly if you see it happening."

Although sand dunes don't exactly fall under the Occupational Safety and Health Administration's jurisdiction, OSHA certainly recognizes trenches of all shapes and sizes as hazards, says H. Berrien Zettler, deputy director for construction.

OSHA has investigated 24 fatalities resulting from cave-ins in the last year alone, he tells WebMD. "It's a serious issue. People don't realize that dirt, or sand for that matter, is extremely heavy. It makes it impossible for people to exercise their abdominal muscles to draw in air; essentially, they suffocate."

The sheer weight of sand causes the collapse, says Zettler. "And people don't have to be completely covered with it to suffocate. Chest deep could be enough to do it -- you just can't draw air. If you're sitting down, it takes even less -- just two or three feet of sand -- to cover your chest."

Although wet sand looks hard, it's actually extremely unstable, because nothing is holding it together, says Zettler. "There's no cohesion like you find in clay soil. You dig into it, and it's like a liquid."

Be careful out there. Keep an eye on our children.

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Saturday, February 24, 2007

Rejuvenating Soil Life Requires Patience

Soil data is "noisy" data. Being a difficult medium to observe and measure, soil has an almost weird capacity to mask change.

In several instances that I can recall, it seemed improvement in soil carbon status was not evident until several years after a change in management was made. The increases in soil organic matter called intervening data into question.

You can see similar data fluctuations due to individual samplers, but this delayed stepping pattern of carbon increase happens a little too often to ignore. It is as if the momentum for an increase in carbon must first collect in the biological dynamic of the soil, invisible to our simple agricultural analysis tools where we measure TKN, TOC and C:N ratios. Those were my thoughts as I read the following:

The Four Phases of No-Till

Phase one, initialization, occurs in the first five years. It is where soil structure starts to improve and microbial activity increases. Additional nitrogen is required to do that.

"As organic matter increases, you need the added nitrogen to make more of it," Towery said.

The second phase is transition from the fifth to tenth years. This is when organic matter accumulates, soil aggregation and soil microbial activity elevates, phosphorous accumulates, and nitrogen immobilization and greater mineralization occurs.

Phase three is consolidation, from 11 to 20 years. In this period, carbon accumulates and additional water is available in the soil. Further nitrogen mineralization and immobilization occurs and there is an increase in cation exchange capacity (CEC) and nutrient cycling.

"These years aren't perhaps exact, because this phase depends on your latitude and your soils," Towery said.

The fourth and final phase is maintenance, which comes after 20 years. It brings a continuous flow of nitrogen and carbon, greater availability of water and high nutrient cycling with increases in nitrogen and phosphorus.

"Twenty years is a long time. It's not like you've arrived at the Promised Land but things do change with the soil," Towery said. "It's because it is a dynamic system. The technology and management strategies you use changes over time as you go from phase to phase.

"One change we underestimate is the changes in soil biology. We can't see them but they're there."

Photo: No-Till Milo in Wheat Stubble

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Home Grown Biofertilizer

The role that soil microbes (archaea, bacteria, and fungi) play in soil nutrient availability is an interesting area, one where we have much to explore. Biofertilizers are increasingly available commercially, meaning those of us outside the academic community will have increasing opportunity to conduct our own reseach. From Montana State University:

Some soil bacteria and fungi can access otherwise unavailable phosphorus, and some are commercially available. In a study on barley, one of these bacteria increased phosphorus availability by about 10 percent. In another study, a phosphate-solubilizing fungus was found to increase spring wheat grain yield by nine percent. "For both studies, the economics need to be considered to determine if these increases are worthwhile, and additional research is needed to determine the effectiveness of these products for different crops and soils," Jones said.

Growing your own biofertilizer may not be that difficult, depending on what it is you are trying to grow. Pictured is some compost tea starter I am "growing" for tomorrow's 36 hour run of actively aerated compost tea. I am going for a fungi-rich tea. Since the aerated tea process favors population growth of bacteria (and, one would think, archaea) over fungi, I am giving the fungi a boost before I start the tea. To 2 cups of compost, I have mixed in 3 tbs oat bran (the white flecks) and 1 tsp of T and J Enterprises (Spokane, WA)'s trichoderma rich "Soil Life & Activator" mix. As you can see the fungi is doing mighty fine. My first couple runs at promoting fungi growth were not as successful. By the looks of this one I am starting to get the hang of it.

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Friday, February 23, 2007

My Interesting Experience With Biosolids

It's May 5, 2005 on a biosolids research plot somewhere between Kennewick WA and Umatilla OR . If you can use either a link to Google Maps or a Google Earth kmz file, the plots start 250' S, 150' E of the fence line and extend to 650' S, 425' E. The aerial photos Google has up as I post this were evidently taken before our field visit, probably in late winter (January?) 2005. The dark E/W swaths Google shows would be annual ryegrass (Lolium multifloruminvasive winter rye (Secale cereale) growing better than normal in areas which received aggressive application of municipal biosolids. Application was in April, 20042003.

The fellow in the distance is Tom Duebendorfer (Elmira, ID), botanist extraordinaire. Tom is carrying the quadrat to the west end of the application swath south of the one I am in. I am following about 20 minutes behind him. The wire flags (pink) are randomized sample points down the middle of the application swath. That's my soil sampler in the foreground, a Viehmeyer probe. It's a lot easier to get in than it is to get back out. The astute observers among you will have already noticed that the grass in the plot isn't looking so good: it is thick, brown and stubby whereas Tom is walking in a taller but thinner stand of green grass.

The biosolids killed the grass, but how? My thinking is that it is not a simple toxic effect. Impaired growth or necrosis would have expressed itself soon after the April 20042003 application, or prevented stand establishment at the beginning of the 2004 and 2005 season. Instead we had brief lush growth, almost like a growth hormone effect. 2,4-D works that way, but not on grasses.

My conclusion is that the effect is due to abundant nutrient availability and complex weather patterns unique to 2005. The application rate was designed to promote biomass gains. It worked, and as a result, the grass grew lush and depleted the soil moisture. With abnormally low rainfall in March, by April it had run out of moisture and had to close up shop for the year. April rains came too late for this brown grass, but helped relieve drought stress in the normal areas.

Soil nitrate levels were elevated in the brown areas but not to an alarming degree. Tom didn't see any application affect on the plant species composition, but then we have not formally analyzed the data. Composition effects are probably going to occur after 2005, beyond the scope of the study. I expect we would see an increase in annual ryegrassinvasive winter rye at the expense of other species.

Look close and you will see the ryegrass was still able to produce a fair amount of seed. L. multiflorumS. cereale is an invasive species, and was the only component in the system that really seemed to benefit from the aggressive biosolids rates to a degree that increased it's longterm competitive potential. I can think of any number of invasive species that would respond similarly.

As an aside, it is unlikely that Tom and I will be preparing a formal report based on the data. The sludge hauling client went bankrupt shortly after that May 2005 sampling. The study was a condition of satisfying a permit violation. Outside of that original context, it falls off both our urgency/importance project matrices.

Corrections: Application was in 2003, not 2004. Ryegrasss is winter rye, secale cereale, not annual ryegrass lolium multiflorum.

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Wednesday, February 21, 2007

Charcoal amended soil for real

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."


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More on pyrolysis

James, over at The Good Life (Ireland) has been trying out a MIDGE aka modified inverted downdraft gasifier experiment. (MIDGE plans pdf). That is pretty much the direction I have been thinking of heading on my quest for balanced charcoal making. James has a valuable reference to a a book I am definitely going to get: How to Convert Wood into Charcoal & Electricity, by Richard Burton.

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Friday, February 16, 2007

New Feature: My Soils Links Shared Using Google Reader

I have added a side-bar feature, sharing links to feed items that catch my interests. They appear in the order that I come across them. This is the soup from which I am most likely to post.

Like many, I have been using Bloglines to track my various news feeds and blog updates. Bloglines has served me very well and has earned its status as "the world’s most popular free online service for searching, subscribing, publishing and sharing RSS feeds, blogs and rich web content." Yet it hasn't changed much in the year+ I have used it and seems clunkier with each passing month.

Yesterday I moved all my subscriptions over to Google Reader. OPML made it so very easy.

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Wednesday, February 14, 2007

Soils and its role in a changing climate

Roger Pielke Sr., over at his research group's climate science blog, has been holding forth on land use change and its impacts on long-term near surface temperature. His position is that the role of land use must be further emphasized within the climate change framework. Search for "soil" and "land" for a long list of supporting posts.

This goes beyond deforestation and urban heat islands. Dust and alterations in atmospheric water content play unknown roles and interact with albedo in sometimes counterintuitive ways. For example, irrigation warms rather than cools the land. Evaporative cooling is insufficient to drive net cooling of irrigated regions. Soils darkened by moisture absorb more heat than dry soils and re-radiate more heat during the night. This results in warmer nights and warmer average temperatures.

Current climate models are not sensitive to changes in land use. Neither are they sensitive to the soil's role in affecting atmospheric carbon levels.

Soil organic matter, at roughly 1500 GtC, is the single largest compartment of carbon in the active biogeochemical cycle. At 60 GtC annual flux (in either direction), it is 10 times larger than the 5.5 GtC flux due to burning fossil fuel. Yet soil is the component of the carbon cycle that we know the least about.

Most soil scientists agree with the unvalidated concept that soil carbon levels will likely decline in step with temperature increases. Higher biological activity will result in more decomposition of organic matter. One certainly sees a similar relationship between soil carbon and temperature when comparing the effect of elevation, aspect and latitude. That we have yet to validate it is telling.
Current climate models mostly ignore the specific role that soil microbes play in the release of carbon dioxide into the atmosphere. The information they do include is often based on assumptions that have never been tested in the field, and may be wrong or overly simplistic.
Our climate models are telling us we need to become far more efficient and more conservative in managing our planet's carbon, soil-wise and fuel-wise. But our scientific understanding will never be adequate for crafting our full response to climate change.
The fact is that our climate is infinitely complex. The models climatologists use to predict the future are incredibly sophisticated, yet blunt instruments. Scientists can never account for all the variables involved - indeed, no one has successfully come up with a mathematical equation to describe the formation of a single cloud. And scientists are often woefully out of their depth in the real world. History is littered with lives and regimes that were wrecked when science was allowed to drive policy with no thought to humanity. Tearing down the global carbon-based economy to - in theory - replace it at a later date with unproven and undeveloped technologies would be a similar folly. It is only by tempering science with economics and the market, which is the most efficient arbiter of humanity's wants and needs, that smart climate policy can be made.
Science and the market are partners of longstanding. Economic necessity, as the mother of invention, has been driving the advance of science for as long as science has been an identifiable pursuit.

Distorted Vision
Originally uploaded by uaezlulu.

Saturday, February 10, 2007


Step 3: Pyrolysis
Originally uploaded by paleorthid.
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)

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Tuesday, February 06, 2007

The Smell of Healthy Soil

Actinobacteria are a hyphae-producing soil bacteria that, in appearance and behavior, appear to have more in common with soil fungi. Like fungi, they decompose some of the more resistant forms of organic plant residues. Like fungi, they form branching filaments, which resemble the mycelia of fungi. Actinobacteria were originally classified as fungi under the older name Actinomycetes.

As bacteria,
Actinobacteria have cell walls. They grow best in soil when conditions are damp and warm, playing an important role in decomposition of organic materials, such as cellulose and chitin. When the soil dries they produce spores. The wetness and force of rainfall kick these tiny spores up into the air. The moist air easily carries the spores to us so we breathe them in. These spores have a distinctive, earthy smell we often associate with rainfall. The smell comes from a compound, geosmin, which translates to "earth smell". The human nose is exquisitely sensitive to geosmin, able to detect it at concentrations down to 10 parts per trillion. Since the bacteria thrives in moist soil but releases the spores once the soil dries out, the smell is most acute after a rain that follows a dry spell, although you'll notice it to some degree after most rainstorms. Actinobacteria are important to healthy soil function, and are ubiquitous. Thus the smell of healthy soil is similar the world over.

Though they play an important role in soil quality, Actinobacteria are more commonly known for what it produces in the laboratory. Actinobacteria are unsurpassed in their ability to produce many compounds that have pharmaceutically useful properties. In 1940 Selman Waksman discovered that they made actinomycin, a discovery for which he was awarded a Nobel Prize. Hundreds of naturally occurring antibiotics have been discovered in these terrestrial microorganisms, especially from the genus Streptomyces.

Actinobacteria are also involved in nitrogen fixation; they convert atmospheric nitrogen into a form that can be used by plants.

Photo source: the earth smells good
Originally uploaded by kamalawalabear

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Monday, February 05, 2007

Triclosan, Triclocarban Concern

Triclosan and triclocarban are small organic molecules that give antimicrobial properties to personal-care products such as soap, deodorant and toothpaste as well as durable goods such as cutting boards, baby carriers and socks. The environmental persistence of these compounds is remarkable. More than a million pounds of these chemicals flow into the nation's sewers every year. Recently improved laboratory analysis demonstrates that 50 percent of triclosan and 76 percent of triclocarban remain unchanged by aerobic and anaerobic digestion in a typical wastewater facility, where most of it is retained in the solids fraction. We can assume that the same can be said of breakdown in the septic systems that 25% of us use in the USA. Most of these solids get spread on land to fertilize pasture, forest, biomass, fiber, feed and food crops.

Triclocarban has been determined by the FDA as having no verifiable benefit. Despite a lack of evidence that these compounds accomplish anything beneficial, usage rate is very high among consumers. Among the households I have surveyed, it approaches saturation.

It makes little sense to land apply recalcitrant compounds that needlessly get rid of soil microbes. Fomenting the growth of resistant strains of disease organisms is only one concern. Soil functional capacity is largely mediated by living processes. It is the height of folly to jeopardize those functions for a useless consumer item.

US-EPA, which has oversight on land application of biosolids, is studying the situation. More work is needed, but everyone writing on this issue seems to get it: this is not an arrangement that we want to sustain.

Sources: (1), (2), (3), (4), (5), (6)

Update: The American Medical Association took an official stance against adding antimicrobials to consumer products in 2000 and has repeatedly urged the Food and Drug Administration (FDA) to better regulate these chemicals. (Source)

Photo: hand sanitizer
Originally uploaded by chewywong.

Sunday, February 04, 2007

Soil Science has Changed

For Carol, over at the Garden Bloggers Book Club, who comments on a previous post:
...be interesting in knowing how soil science has changed in the last 25+ years. I took an introductory class in soil science in 1978 or 79. And I don't recall much discussion about what was living in the soil. Has that become more of an emphasis?
The short answer to that is, yes.

Let's take a bit of a look back to those times. I took my soils classes mostly in 1974 through 1976 at UC Davis. One was a soil microbiology class, and it covered many of the soil-food-web fundamentals that Jeff Lowenfels expands on in "Teaming with Microbes", but it touched only briefly on species interdependence. Ecology was a fairly new field at the time, and much that we know now as soil ecology was just a glimmer in our eyes.

I took an introductory level ecology class in 1973. My recollection was this was only the second year an ecology class was available at UC Davis.

The emphasis in soil microbiology, at the time, was on the metabolic processes the soil biology contributes to nutrient cycling: respiration, immobilization, symbiotic nitrogen fixation, nitrification, ammonification. Carbon:nitrogen ratios of disked in residue were a big deal due to microbial immobilization. There was a strong emphasis on bacteria, and I don't recall anything said about mycorrhizal fungi.

I remember a deep respect for the living component of soil among my pedologic-oriented instructors: "Dirt is soil without life" was drilled into us countless times whenever we slipped up and used the term "dirt" when we should have used "soil".

My edaphic-oriented instructors were not as soil biology oriented. But this was before "soil health" and "soil quality" movements in agricultural soil science became established. It was also before the interest in wetland soil process, bioremediation, protecting groundwater, and understanding why septic systems fail, combined to drive dramatic changes in edaphology.

Edaphology is the study of soil (edaphic) effects. Until about 25 years ago, it mostly synonymous with agricultural soil science as distinguished from pedology, the study of soil in its natural setting. Edaphology now encompasses the new field of environmental soil science, with its more formal emphasis on interdependent living processes in soil.

Soil science has gone through dramatic changes in the last 25+ years.

Picture Source: The Divine Soil
Originally uploaded by Room With A View.

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Friday, February 02, 2007

Technical Difficulties

January visited a host of computer problems on our household. This culminated with an early dawn motherboard meltdown Wednesday. It was a six-year old machine, so I was pushing my luck. I was hoping to limp it along until Vista was better established.

If the machine had gone out the week before, I would have replaced it with another XP machine. No XP machines were available this week. I bought an HP Pavilion a1730n, 2.4 GHz Athlon 64 X2 with 2 GB of RAM, GeForce 6150 video card w/ 128 MB RAM and one 320 GB SATA HD. There is a 5 inch bay available for another drive. It has a 300 watt power supply. It was off the shelf.

I stripped my old machine. It was a fast machine in its day, made right when DDR RAM came out. It had 2 roastingly hot Athlon processors and a high end graphics card. It had a nasty habit late in life of eating 400+ watt power supplies until I shelled out for a lovely Antec ps. It was noisy, hot and an energy hog. I had grown quite attached to it.

Rosemary got the 2 GB sticks of RAM, which made her quite happy. The 2 and 4 year old WD harddrives turned out to be fine also, but it took me awhile to figure out how to access them. A major problem (I thought) was that there is not a single SATA HD external enclosure in stock within driving distance, and I spent hours pursuing what turned out to be misleading and incorrect information. Finally my tech guy got back in and set me up to transfer files. It was an easy solution. I already had the cables and I should have figured this out myself.

My fears that Vista will make my life miserable are fading fast. Although I have yet to do any billable time on the beast, Vista is looking good. My open source programs appear to be Vista worthy with one exception. Working are OpenOffice.org 2.1, GIMP 2.2, ghostscript 8.54, and my ghostscriptviewer, GSView 4.8. These are all running perkier than I have ever experienced, especially GIMP, the graphics program I rely on for marking up maps.

An open source application not working is my PDFCreator 0.9, which I use heavily for creating pdf invoice and map files to email to clients. The good news is that ghostscript, which PDFCreator relies upon, does not seem to be the problem. A fix can't be too far off.

I haven't loaded all my programs and data yet, but no matter how bad it gets, it looks to be clearer sailing and better winds than we had in January.

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