James Galloway on Nitrogen

This article has just been published by James Galloway and rings a loud alarm over the unheralded failure of the agricultural environment to sponge up all the soluble nitrogen that is been dumped on the land every year to maximize crop yield. This is not a new problem, but it is certainly an ignored problem.

I will make a brave conjecture however and that is that the application of biochar will halt this ongoing nitrogen leachate problem. The evidence available as well as prior work on zeolites conforms to this conjecture. The mere fact that terra preta retains fertility in a rainforest environment additionally supports this conjecture. What we lack is a good scientific work up that can be used by all proponents.

The reason that this mechanism works is the existence of solid crystalline acids throughout the biochar matrix caused by the heating process. These immobile acids grab mobile free ions such as nitrogen ions and other fertilizer ions and holds them until a living organism plucks them free.

That is why I am quite happy to have the commercial fertilizer industry produce powdered coked coal as a fertilizer media to deliver the nutrients to the soil. If every free fertilizer ion arrived in the soil bound to charcoal, then there would be little escapement of the fertilizer into the ground water.

I suspect that if we had a true understanding of soil nutrient dynamics, a carbon protocol would have been mandated decades ago.

The corollary of this conjecture is that the amount of applied fertilizer can be cut dramatically. Again we simply do not have the science worked up as yet. Perhaps we need to convince the fertilizer industry that they can make as much money shipping carbon as shipping fertilizer.

To be fair, the industry surely works to a price point based on a dollar price per treated acre. That will not change at all. The question is then about the costs of additives and fillers. Displacing ten percent of the filler with powdered coked coal is no trick at all. If that then leads to a fifty percent drop in the actual chemical percentage with the same agricultural result, we may even have a net drop in costs.

It would be a sweet irony if the advent of a proper carbon buffered fertilizer protocol succeeded in been more profitable than all previous protocols.


Public release date: 15-May-2008

Contact: James Galloway

jng@virginia.edu434-924-1303University of Virginia

Addressing the 'nitrogen cascade'

Papers in Science discuss incessant cycling of reactive nitrogen in environment

While human-caused global climate change has long been a concern for environmental scientists and is a well-known public policy issue, the problem of excessive reactive nitrogen in the environment is little-known beyond a growing circle of environmental scientists who study how the element cycles through the environment and negatively alters local and global ecosystems and potentially harms human health.

Two new papers by leading environmental scientists bring the problem to the forefront in the May 16 issue of the journal Science. The researchers discuss how food and energy production are causing reactive nitrogen to accumulate in soil, water, the atmosphere and coastal oceanic waters, contributing to the greenhouse effect, smog, haze, acid rain, coastal "dead zones" and stratospheric ozone depletion.

"The public does not yet know much about nitrogen, but in many ways it is as big an issue as carbon, and due to the interactions of nitrogen and carbon, makes the challenge of providing food and energy to the world's peoples without harming the global environment a tremendous challenge," said University of Virginia environmental sciences professor James Galloway, the lead author of one of the Science papers and a co-author on the other. "We are accumulating reactive nitrogen in the environment at alarming rates, and this may prove to be as serious as putting carbon dioxide in the atmosphere."

Galloway, the founding chair of the International Nitrogen Initiative, and a co-winner of the 2008 Tyler Prize for environmental science, is a longtime contributor to the growing understanding of how nitrogen cycles endlessly through the environment. In numerous studies over the years he has come to the realization of the "nitrogen cascade," and has created with his colleagues a flow chart demonstrating the pervasive and persistent effects of reactive nitrogen on Earth's environment (www.initrogen.org).

In its inert form, nitrogen is harmless and abundant, making up 78 percent of the Earth's atmosphere. But in the past century, with the mass production of nitrogen-based fertilizers and the large-scale burning of fossil fuels, massive amounts of reactive nitrogen compounds, such as ammonia, have entered the environment.

"A unique and troublesome aspect of nitrogen is that a single atom released to the environment can cause a cascading sequence of events, resulting ultimately in harm to the natural balance of our ecosystems and to our very health," Galloway said.

A nitrogen atom that starts out as part of a smog-forming compound may be deposited in lakes and forests as nitric acid, which can kill fish and insects. Carried out to the coast, the same nitrogen atom may contribute to red tides and dead zones. Finally, the nitrogen will be put back into the atmosphere as part of the greenhouse gas nitrous oxide, which destroys atmospheric ozone.

Galloway and his colleagues suggest possible approaches to minimizing nitrogen use, such as optimizing its uptake by plants and animals, recovering and reusing nitrogen from manure and sewage, and decreasing nitrogen emissions from fossil fuel combustion.

"Nitrogen is needed to grow food," Galloway says, "but because of the inefficiencies of nitrogen uptake by plants and animals, only about 10 to 15 percent of reactive nitrogen ever enters a human mouth as food. The rest is lost to the environment and injected into the atmosphere by combustion.

"We must soon begin to manage nitrogen use in an integrated manner by decreasing our rate of creation of reactive nitrogen while continuing to produce enough food and energy to sustain a growing world population.”

Galloway's next effort is to create a "nitrogen footprint" calculator that people can access on the Internet, very similar to current "carbon footprint" calculators.

He says people can reduce their nitrogen footprints by reducing energy consumption at home, traveling less, and changing diet to locally grown vegetables (preferably organic) and fish and consuming less meat.

Galloway is quick to point out that along with the problems of excess reactive nitrogen in many areas of the world, there also are large regions, such as Africa, with too little nitrogen to grow enough food for rapidly growing populations. In those regions, the challenge is find ways to increase the availability of nitrogen while minimizing the negative environmental effects of too much nitrogen.

I copied this out of a post by Ron Larson. An industrial fertilizer should thus easily avoid almost any nitrogen losses.

“My knowledge on the relationship between nitrogen and biochar mostly comes from a visit to one nitrogen researcher in Australia last year (Dr. Lukas van Zweiten at IAI conference) who claims 80% reduction in nitrous oxide release in field trials with biochar (see towards end of

http://pubs.acs.org/subscribe/journals/esthag-w/2007/aug/tech/rr_biochar.html?sa_campaign=rss/cen_mag/estnews/2007-08-01/rr_biochar ).

Note that most nitrous oxide comes from agriculture, so 80% is potentially a big deal - and N2O is much worse than CO2 for climate impacts.”

Erich Knight's Biochar list

As long time readers know, I have been promoting terra preta steadily since just after I started this blog. Erich Knight has constructed an inventory of pertinent sites and articles for this topic. Since I started posting, the volume of interest has expanded hugely. I recently posted on the terra preta forum and the response volume was overwhelming. I found myself with dozens of comments as follow up with a lot of good information and thinking.

Anyway this list he has constructed is a good snapshot of the best current sites. I suspect that next year, the number will be much larger.


The best Win Win Win solution is Biochar.

The current news and links on Terra Preta (TP) soils and closed-loop pyrolysis of Biomass, this integrated virtuous cycle could sequester 100s of Billions of tons of carbon to the soils.

This technology represents the most comprehensive, low cost, and productive approach to long term stewardship and sustainability.Terra Preta Soils a process for Carbon Negative Bio fuels, massive Carbon sequestration, 1/3 Lower CH4 & N2O soil emissions, and 3X Fertility Too.

UN Climate Change Conference: Biochar present at the Bali Conference

http://terrapreta.bioenergylists.org/steinerbalinov2107SCIAM Article May 15 07;

http://www.sciam.com/article.cfm?articleID=5670236C-E7F2-99DF-3E2163B9FB144E40After many years of reviewing solutions to anthropogenic global warming (AGW) I believe this technology can manage Carbon for the greatest collective benefit at the lowest economic price, on vast scales. It just needs to be seen by ethical globally minded companies.Could you please consider looking for a champion for this orphaned Terra Preta Carbon Soil Technology.

The main hurtle now is to change the current perspective held that the soil carbon cycle is a wash, to one in which soil can be used as a massive and ubiquitous Carbon sink via Charcoal Below are the first concrete steps in that direction;

S.1884 The Salazar Harvesting Energy Act of 2007

A Summary of Biochar Provisions in S.1884:

Carbon-Negative Biomass Energy and Soil Quality Initiative for the 2007 Farm Bill

Bolstering Biomass and Biochar development: In the 2007 Farm Bill, Senator Salazar was able to include $500 million for biomass research and development and for competitive grants to develop the technologies and processes necessary for the commercial production of biofuels and bio-based products. Biomass is an organic material, usually referring to plant matter or animal waste. Using biomass for energy can reduce waste and air pollution. Biochar is a byproduct of producing energy from biomass. As a soil treatment, it enhances the ability of soil to capture and retain carbon dioxide.

http://www.biochar-international.org/newinformationevents/newlegislation.htmlThere are 24 billion tons of carbon controlled by man in his agriculture and waste stream, all that farm & cellulose waste which is now dumped to rot or digested or combusted and ultimately returned to the atmosphere as GHG should be returned to the Soil.

If you have any other questions please feel free to call me or visit the TP web site I've been drafted to co-administer.

http://terrapreta.bioenergylists.org/?q=nodeIt has been immensely gratifying to see all the major players join the mail list , Cornell folks, T. Beer of Kings Ford Charcoal (Clorox), Novozyne the M-Roots guys(fungus), chemical engineers, Dr. Danny Day of EPRIDA , Dr. Antal of U. of H., Virginia Tech folks and probably many others who's back round I don't know have joined.

The International Biochar Initiative (IBI) conference held at Terrigal, NSW, Australia in 2007. The papers from this conference are posted at their home page;

http://www.biochar-international.org/home.html.Nature article, Aug 06: Putting the carbon back Black is the new green:

http://bestenergies.com/downloads/naturemag_200604.pdfHere's the Cornell page for an over view:

http://www.css.cornell.edu/faculty/lehmann/biochar/Biochar_home.htmUniversity of Beyreuth TP Program, Germany

http://terrapreta.bioenergylists.org/?q=taxonomy/term/118This Earth Science Forum thread on these soils contains further links, and has been viewed by 19,000 self-selected folks. ( I post everything I find on Amazon Dark Soils, ADS here):

http://forums.hypography.com/earth-science/3451-terra-preta.htmlTerra Preta creates a terrestrial carbon reef at a microscopic level. These nanoscale structures provide safe haven to the microbes and fungus that facilitate fertile soil creation, while sequestering carbon for many hundred if not thousands of years. The combination of these two forms of sequestration would also increase the growth rate and natural sequestration effort of growing plants.

All the Biochar Companies and equipment manufactures I've found:

Carbon Diversion

http://www.carbondiversion.comEprida: Sustainable Solutions for Global Concerns

http://www.eprida.com/home/index.php4BEST Pyrolysis, Inc. Slow Pyrolysis - Biomass - Clean Energy - Renewable Energy

http://www.bestenergies.com/companies/bestpyrolysis.htmlDynamotive Energy Systems The Evolution of Energy

http://www.dynamotive.com/Ensyn - Environmentally Friendly Energy and Chemicals

http://www.ensyn.com/who/ensyn.htmAgri-Therm, developing bio oils from agricultural waste

http://www.agri-therm.com/Advanced BioRefinery Inc.

http://www.advbiorefineryinc.ca/Technology Review: Turning Slash into Cash

http://www.technologyreview.com/Energy/17298/3R Environmental Technologies Ltd. (Edward Someus)

WEB: http://www.terrenum.net/

The company has Swedish origin and developing/designing medium and large scale carbonization units. The company is the licensor and technology provider to NviroClean Tech Ltd British American organization WEB: http://www.nvirocleantech.com and VERTUS Ltd.

http://www.vertustechnologies.comGenesis Industries, licensee of Eprida technology, provides carbon-negative EPRIDA energy machines at the same cost as going direct to Eprida. Our technical support staff also provide information to obtain the best use of biochar produced by the machine. Recent research has shown that EPRIDA charcoal (biochar) increases plant productivity as it sequesters carbon in soil, thus reducing atmospheric carbon dioxide.

http://www.egenindustries.com/If pre-Columbian Kayopo Indians could produce these soils up to 6 feet deep over 15% of the Amazon basin using "Slash & CHAR" verses "Slash & Burn", it seems that our energy and agricultural industries could also product them at scale.

Harnessing the work of this vast number of microbes and fungi changes the whole equation of energy return over energy input (EROEI) for food and Bio fuels. I see this as the only sustainable agricultural strategy if we no longer have cheap fossil fuels for fertilizer.We need this super community of wee beasties to work in concert with us by populating them into their proper Soil horizon Carbon Condos.

Erich J. Knight
Shenandoah Gardens
1047 Dave Berry Rd.
McGaheysville, VA. 22840
(540) 289-9750
shengar@aol.com

Earthen Terra Preta Kilns and Pollen Spectrum

I am reposting this article by David Bennet with Lehmann on Terra Preta in 2005. This reconfirms the most critical information as well as describes the original scope of the Amazonian Indian civilization itself.

Again this lays out the limiting factors and fully supports my earthen kiln conjecture.

Firstly, the maize or corn exists in an environment that mitigated against its use for purely food production. There were alternatives far better suited to the non terra preta environment, starting immediately with manioc which is a rainforest friendly plant.

Secondly, the only viable source of meat protein to these peoples at this population density was fish. Without confirmation, a pond with tilapia makes great sense. The waste from the daily meal could be readily folded into any growing seed hill. Human waste could simply have been buried in the field itself avoiding any storage. This is common practice to this day.

The making of the earthen kiln is no more difficult than uprooting the dehydrated corn stalks and properly stacking them to form an earthen walled kiln with a wall thickness of two to three root pads and an interior of tightly packed corn stalks. Obviously, any other plant material, including wood can be built into the stack as available. The earthen wall nicely restricts air flow during the burn phase and lends itself to optimization by changing the thickness. It also minimizes the amount of human effort needed which is through the roof if you are attempting to cover a pile of stubble or branches.

This gives you a kiln with vertical earthen walls and a possibly domed top that can be easily covered with earth. Again, field trials will optimize this protocol very easily. The kiln could be squared of or perhaps even circular though unlikely. The only tool to this point is a strong back or two. We have gathered several tons of corn stover over perhaps an acre of land with only a little more effort than that required to clear the field and burn the waste.

Now we must fire the kiln. The easy way is to take a clay lined old basket and fill it up with coals from a wood fire. Carry this ember charge to the center of the kiln top and tip the charge onto the exposed center and place the basket as a cap to the newly forming chimney. More clay may be necessary to widen the chimney cap. Throw more earth on top of this to prevent breakout of the fire. Keep growing earth on any breakout points that start. The chimney will serve to burn all the volatiles produced as the hot zone expands to fill the collapsing kiln until they are exhausted. Thereupon the hot zone will cool off leaving a blend of biochar, ash and earth and some root ends for the next kiln. And yes, we should have a lot of fired clay.

The biochar itself will be a range of nonvolatile combustion products that will range from even dried vegetation to activated charcoal following a nice bell curve. The material can be then gathered in baskets and redistributed into the field onto the seed hills again reducing wastage and effort.

I realized originally that the only ancient plant that could accommodate a high enough volume of terra preta production was good old maize. It just seemed an unlikely option for tropical rainforests. That is when I started looking for references to the pollen record. The article by David Bennett and Lehmann is one of those reverences that then emerged.

I would like to get a full spectrum of the pollen profile since it seems very likely that while the fence rows held the food trees, it seems more likely that they also used a variation of the three sisters using some form of convenient legume. Squashes also, of course, but not nearly as important.

The key point of all this is that a family can convert a field into terra preta in one short season, allowing them to repeat the process thereafter as necessary until the field is completely transformed to depth. Today, we can do the same thing using shovels and a garbage can lid.

Terra preta: unearthing an agricultural goldmine

Nov 14, 2005 10:36 AM, By David Bennett

Many soil scientists insist an ancient Amerindian agrarian society will soon make a huge impact on the modern world. They say once the intricacies and formulation of the society’s “terra preta” (dark earth) is unlocked, the benefits will help stop environmental degradation and bring fertility to depleted soils. Developing and developed nations will benefit.

Orellana

The story goes that in 1542, while exploring the Amazon Basin near Ecuador in search of El Dorado, Spanish conquistador Francisco de Orellana began checking the area around one of the Amazon’s largest rivers, the Rio Negro. While he never found the legendary City of Gold, upon his return to Spain, Orellana reported the jungle area held an ancient civilization — a farming people, many villages and even massive, walled cities.

Later explorers and missionaries were unable to confirm Orellana’s reports. They said the cities weren’t there and only hunter-gatherer tribes roamed the jungles. Orellana’s claims were dismissed as myth.

Scientists who later considered Orellana’s claims agreed with the negative assessments. The key problem, they said, was large societies need much food, something Amazonia’s poor soils are simply incapable of producing. And without agriculture, large groups of people are unable to escape a nomadic existence, much less build cities.

Dark earth

More recently, though, Orellana’s supposed myths have evolved into distinct possibilities. The key part of the puzzle has to do with terra preta.

It turns out that vast patches of the mysterious, richly fertile, man-made soil can be found throughout Amazonia. Through plot work, researchers claim terra preta can increase yields 350 percent over adjacent, nutrient-leached soils.

Many well-respected researchers now say terra preta, most of it still hidden under jungle canopy, could have sustained large, agronomic societies throughout Brazil and neighboring countries.

Amazing properties

The properties of terra preta are amazing. Even thousands of years after creation, the soil remains fertile without need for any added fertilizer. For those living in Amazonia, terra preta is increasingly sought out as a commodity. Truckloads of the dark earth are often carted off and sold like potting soil.

Chock-full of charcoal, the soil is often several meters deep. It holds nutrients extremely well and seems to contain a microbial mix especially suited to agriculture.

Thus far, despite great effort, scientists have been unable to duplicate production of the soil. If researchers can ever uncover the Amerindians’ terra preta cocktail recipe, it will help stop the environmentally devastating practice of slash-and-burn agriculture in the Amazon jungle. Terra preta’s benefits will also be exported across the globe.

However, even without unlocking all of the soil’s secrets, things learned in the study of it are already being brought to row-crop fields.

Among researchers studying terra preta is Johannes Lehmann, a soil fertility management expert and soil biogeochemistry professor at Cornell University. Lehmann, who recently spoke with Delta Farm Press, says things learned from terra preta will help farmers with agricultural run-off, sustained fertility and input costs. Among his comments:

On how Lehmann came to terra preta research…

“I spent three years living and working in degraded Amazonia field sites. Inevitably, if you work in the central Amazon, you come across terra preta.

“The visual impact of these soils is amazing. Usually, the soils there are yellow-whitish colored with very little humus. But the terra preta is often 1 or 2 meters deep with rich, dark color. It’s unmistakable. We know terra preta are preferentially cropped.”

On the various properties of terra preta and its modes of action…

“There are a few factors that contribute to this fertility — sustainable fertility. Remember, these are soils that were created 1,000 to 5,000 years ago and were abandoned hundreds or thousands of years ago. Yet, over all those hundreds of years, the soils retain their high fertility in an environment with high decomposition, humidity and temperatures. In this environment, according to text books, this soil shouldn’t exist.

“That alone is fascinating for us.

“Among the most important properties are high nutrient concentrations (especially for calcium and phosphorus). Most likely, this is linked to a unique utilization of agricultural and fishery waste products.

“We believe that fish residues are an important portion of the high phosphorus concentrations. Phosphorus is really the number one limiting nutrient in the central Amazon.

“Another interesting aspect of terra preta’s high fertility is the char (charcoal) content of the soil. This was deliberately put into the soil by the Indians and doesn’t only create a higher organic matter — and therefore higher fertility through better nutrient-retention capacity — but this special type of carbon is more efficient in creating these properties.

“You can have the same amount of carbon in terra preta and adjacent soils and the infertile soil won’t change. Terra preta’s abilities don’t just rely on more carbon, but the fact that its char and humus is somehow more efficient in creating beneficial properties. That’s the truly unique aspect.”

Having lived in the Amazon and studied it, how much terra preta does Lehmann believe there is?

“There are no precise numbers of how much terra preta there is (in Amazonia). No one has done any large-scale investigation of that. It’s very difficult to find out in the Amazon’s jungle environment. Suitable remote-sensing techniques haven’t yet been used.

“So (the 10 percent) estimates sometimes cited are crude extrapolations from the few areas we’re familiar with. But we know that in familiar areas there are huge patches of terra preta. These are hundreds of hectares large. When there have been maps produced of areas containing terra preta — say an area around a stream — patches are everywhere.

“It is also true that terra preta is widespread. Almost anywhere in the central Amazon, you can step out of the car and ask a local ‘Is there any terra preta around?’ and they’ll show you. It’s everywhere.”

What were the Indians growing? Tree crops? Row crops?

“There has been some pollen analysis. It suggests manioc and maize were being grown 2,000 to 3,000 years ago. In the pollen bank, these crops didn’t pop up sporadically but in large numbers.

“But all kinds of crops were grown by the Indians. Palm trees, under-story fruit trees, Brazil nut trees — all were very important.”

On the differences between slash-and-burn and slash-and-char agriculture…

“We have very good indications that the Amerindian populations couldn’t have practiced slash-and-burn and created these soils.

“It’s also highly unlikely that a population relying on stone axes would have practiced slash-and-burn anyway. The normal soils are so poor that with a single slash-and-burn event, you can only crop without fertilizer for two years at most. Then the soil has to be left fallow again.

“Primary forest trees have a diameter of 2 or 3 meters. If all you had was a stone ax in your hand, you’d find a different way to deal with agriculture than felling these huge trees every two years.

“The difference between (the two systems) is the slash-and-char wouldn’t burn in an open fire. Charcoal would be produced under partial exclusion of oxygen. We envision that happening by natives covering up piled up logs with dirt and straw. These charcoal-making systems are still being used around the world.”

How close are researchers to duplicating terra preta?

“We’re working intensively. We don’t need to take any terra preta anywhere. What we want to do is become knowledgeable about how terra preta was created and then create it elsewhere with local resources.

“Research on this is ongoing in Columbia, in Kenya. I have research colleagues in Japan and Indonesia also working on this. At the moment, there is a lot of excitement but there’s a lot of work to do.”

How terra preta could help industrialized countries…

“We envision systems based on some of the principles of terra preta. And this isn’t just for tropical agriculture. This could be very important for U.S. agriculture.

“Terra Preta could mean a reduction in environmental pollution. What works as a retaining mechanism in Amazonia could work in the United States where there are concerns of phosphates and nitrates entering groundwater and streams. We have only begun to realize the potential of how this could reduce pollution in industrialized countries.

“Luckily the principles of creating bio-char soils will be very similar no matter what area of the world you’re in. Results obtained in Brazil will be pertinent for the United States.

“In terms of widespread adoption, it’s still some way away. There are still knowledge gaps. For instance, we know there are important differences in the effects of bio-char on soil fertility depending on what material you use and what temperature and under what conditions the char is produced. That’s something we should be able to resolve within a year or two. Once that’s done, we can take the systems to Extension Services around the world and make larger scale, on-farm research plots.

“We’re already working with dozens of Kenyan farmers on this. The project only began this year. By next year, we hope to have a better idea of how this works on farms.”

Where will the bio-char come from?

“Perhaps agricultural and forestry waste products could be the answer.

“Something else that gets us very excited is a link to energy production systems (utilizing) pyrolysis...

“Really, pyrolysis is a just a complicated word for making charcoal. Prototypes of this system for commercial power plants have been developed. These create bio-oil, hydrogen and other co-products — including bio-char — from the production of charcoal.

“We want to gain a better understanding of what effects this bio-char has on soil functions. It should be quite similar to a bio-char produced in a kiln or field. Such a system will be an entry point for large-scale production and use.

“There are competing uses for the power plant byproducts. Currently, power plants either use the byproducts for their own energy needs or they sell it to be used as charcoal briquettes.

“It could become profitable as soon as some of the environmental effects — currently external — are internalized. For instance, cleaner streams, cleaner groundwater, carbon sequestration and other things.”

For more information, visit www.css.cornell.edu/faculty/lehmann/terra_preta/TerraPretahome.htm

Doubling Crop Production

This item came out last summer and is a report on a field trial using biochar in Australia. Most importantly they mixed biochar at the rate of ten tons per acre. This is equivalent to any likely protocol that will be used by farming over a ten to twenty year cycle with corn or bagasse or any other natural biomass source to achieve the same result..

The yield doubled over all obvious variations on soils that are known to be somewhat infertile and even slightly toxic. This confirms the contention that all soils can likely be optimized to full optimal fertility throughout the globe. This is an astounding idea. We already know it works in the impossible rainforest environment and now we know it can be used on the unforgiving semi tropical nutrient depleted Australian soils.

Prior work supporting this contention came from the work done on zeolites by the Cubans. Zeolites and carbon are also known, if activated, as solid crystalline acids. So it comes as no surprise that enrichment with a strong dose of char will reconstitute soil biome in way that strongly supports general fertility.

I have already suggested that at the subsistence level of agriculture, char can be distributed in hills, reducing the initial dilution with soil for maximum initial utility. The char itself can be made up in a drum, if the supply is small or alternately in an earthen kiln best made from corn stover using the root pads to build the outer shell.
In large scale operations with an industrial kiln available, it is likely best to convert a small sub field each year to full terra preta status.

As I have been posting, this soil revolution will optimize every farm field on earth and lead to a possible near doubling of global production just on the lands we now use. The real payoff will be in the tropics were this method, perhaps using earthen kilns, will allow tropical soils to be fully exploited rather than present slash and burn.

There are very few places on earth where maximum fertility is achieved. I likely live in one of them. But I have walked over many hungry looking fields and have seen many areas that screamed for fertility management. One memory was driving through Germany any seeing a lone straggling blackberry vine in the fencerow. Later that afternoon, my uncle showed me his prize blackberry vine in his garden. In the Fraser Valley, black berry vines inundate the empty spaces if given half a chance producing true impenetrable barbed jungles. Yet the climate is just as benign in Germany. The only difference is a thousand years of hard cropping.

In short, even without watering the deserts, the world can handle a population of ten to twenty billion with this knowledge.

Friday, June 01, 2007

Research confirms biochar in soils boosts crop yields

New research confirms the huge and revolutionary potential of soils to reduce greenhouse gases on a large scale, increase agricultural production while at the same time delivering carbon-negative biofuels based on feedstocks that require less fertilizer and water. Trials at Australia's New South Wales Department of Primary Industries’ (DPI) Wollongbar Agricultural Institute show that crops grown on agrichar-improved soils received a major boost. The findings come at a time when carbon-negative bioenergy is becoming one of the most widely debated topics in the renewable energy and climate change community.

The Australian trials of 'agrichar' or 'biochar' have doubled and, in one case, tripled crop growth when applied at the rate of 10 tonnes per hectare. The technique of storing agrichar in soils is now seen as a potential saviour to restore fertility to depleted or nutrient-poor soils (especially in the tropics), and as a revolutionary technique to mitigate climate change. Moreover, agrichar storage in soils is a low-tech practise, meaning it can be implemented on a vast scale in the developing world, relatively quickly.

Agrichar is a black carbon byproduct of a process called pyrolysis, which involves heating biomass without oxygen to generate renewable energy. Pyrolysis of biomass results in the production of bio-oil, that can be further refined into liquid biofuels for transport (earlier post, on Dynamotive's trials). When the agrichar is consequently sequestered into soils, the biofuels become carbon-negative - that is, they take more carbon dioxide out of the atmosphere than they release. This way, they can clean up our past emissions. No other renewable energy technology has both the advantages of being carbon-negative while at the same time being physically tradeable.

The biochar sequestration technique is now confirmed to boost soil fertility while storing carbon long-term. New South Wales Department of Primary Industries' senior research scientist Dr Lukas Van Zwieten said soils naturally turn over about 10 times more greenhouse gas on a global scale than the burning of fossil fuels.

“So it is not surprising there is so much interest in a technology to create clean energy that also locks up carbon in the soil for the long term and lifts agricultural production,” he said.

Multiple benefits

The trials at Wollongbar have focused on the benefits of agrichar to agricultural productivity: “When applied at 10t/ha, the biomass of wheat was tripled and of soybeans was more than doubled,” said Dr Van Zwieten. This percentage increase remained the same when applications of nitrogen fertiliser were added to both the agrichar and the control plots. For the wheat, agrichar alone was about as beneficial for yields as using nitrogen fertiliser only. And that is without considering the other benefits of agrichar.

Regarding soil chemistry, Dr Van Zwieten said agrichar raised soil pH at about one-third the rate of lime, lifted calcium levels and reduced aluminium toxicity on the red ferrosol soils of the trial. Soil biology improved, the need for added fertiliser reduced and water holding capacity was raised. The trials also measured gases given off from the soils and found significantly lower emissions of carbon dioxide and nitrous oxide (a greenhouse gas more than 300 times as potent as carbon dioxide):

Dominic Woolf on Biochar

Dominic Woolf has recently published a thirty page study on biochar titled ‘Biochar as a soil amendment: A review of the environmental implications’

http://orgprints.org/13268/01/Biochar_as_a_soil_amendment_-_a_review.pdf

This report is a bit too long to republish in its entirety but I think it is useful to copy the summary conclusions. I will likely copy other portions with commentary as appropriate.

It is worth reading in its entirety as it will bring the reader completely up to date with the present apparent state of the art. My one comment is more in line with my own proposed methodology for production as likely employed by the Amazonians. It is that industrial techniques such as metal kilns or barrels are isolating the feedstock during the burn phase.

The corn culture earthen kiln should not only be reasonably efficient but also more inefficient in terms of the completeness of the burn. I suspect that this matters in practice and I would hate to miss something important by sticking to modern kilns.

I sense that a collapsed earthen kiln will leave a high quality biochar blended with an appropriate amount of soil, whereas a metal kiln will produce a uniform powdered char product with far less variation and perhaps much less biological utility. We need to compare both protocols in the field to see what we should be striving for.

9. Summary

In conclusion, we can say that biochar appears, given the current state of knowledge, to have potential both for greenhouse gas mitigation and as a soil improver. Considerable uncertainties remain, however, about its applicability to different soils and crops and about how much biochar production is feasible with respect to constraints on economics, land availability and competing demands for biomass (including direct incorporation into the soil). The uncertainties and areas requiring further research are outlined below:

• A maximum of 1 PgCyr-1 biochar might be produced from agricultural residues (if all current global agricultural residues were converted to biochar). In practice, this figure will be constrained by cost, suitability of different residues, requirements to incorporate residues into the soil, and other competing demands.

How much biochar might be produced from agricultural residues once such constraints have been taken into account is a matter for further research.

• Estimates of how much biomass might be produced by dedicated cropping remains a highly debated question. At the low end, figures from Sims et al (2006) suggest that between 0.06 - 0.7 PgC yr-1 might be realistically achievable by 2025. At the high end, figures from Smeets et al (2007) suggest that up to 46 PgC yr-1 might be achievable if we were to transform the planet into a large factory farm. More detailed studies at the local level will be required to ascertain the true potential for dedicated production of biomass.

• Other potential sources of biomass include shifting cultivation, forestry residues, sewage and waste streams such as food waste and paper/cardboard. Further research will be required to ascertain the combined potential of all possible sources of biomass for biochar production.

• How rapidly biochar may oxidise in different environments is still largely unknown, although its observed recalcitrance under many conditions gives reason for optimism that the rate of decay of black carbon in soil will be sufficiently slow to make it a useful form of carbon sequestration.

• Co-production of biochar and energy is clearly possible (as demonstrated by the fact that pyrolysis technologies designed for energy production alone produce a residue of char). However, there is a conflict between maximising energy or biochar production. For a 45% yield of char, a maximum of 32% of the available energy from the biomass will be recoverable. For a 20% yield of char on the other hand, a maximum of 72% of the available energy from the biomass will be recoverable. The optimisation between biochar and energy production will require balancing considerations of climate change mitigation, energy demand, economics and engineering, and requires further research and development.

• Whilst a beneficial effect of biochar soil additions on crop yields has been demonstrated for a small number of soil/crop combinations, its utility in a wide range of soil/crop types (particularly in temperate zones) remains to be demonstrated. This will require consideration not just of its effect on nutrient cycles, but also on hydrology.

• The effect of biochar production on nitrous oxide emissions is largely an unknown factor. Although there is a possibility that biochar additions may reduce N2O direct emissions from soils, and may also reduce indirect N2O emissions by

reducing nitrate run-off, neither of these possibilities has been adequately demonstrated under a range of different agricultural conditions. There is also the possibility that, if biochar is produced by dedicated cropping with application of mineral nitrogen fertilizer, the direct and indirect N2O emissions from this fertilizer will lead to an increase rather than a decrease in net N2O emissions.

• Biochar has the potential to either alleviate pressure on land use (by increasing crop yields) or to become a competing demand for land (in the case of dedicated cropping for biomass feedstock). Either way, the role of biochar in establishing a comprehensive land use strategy that meets the environmental, social and economic needs of the 21st century is in need of further consideration.

• It is possible that biochar may help to reduce nutrient run-off from soils and the associated problems of eutrophication and hypoxia of both inland and coastal waters. In what soils and under what conditions this might in fact be achieved remains to be shown. There is evidence that under some conditions, biochar may have the opposite effect of increasing leaching of applied mineral fertilizers.

• Despite its potential to reduce greenhouse gas emissions, the widespread land application of biochar might also have a detrimental effect on global warming by increasing the radiative forcing due to albedo. The extent to which this may be a problem, and the extent to which this may be mitigated by strategies such as maintaining a dense vegetation canopy over darkened soils requires further research.

Given the serious potential impacts of anthropogenic climate change, and the significant potential of biochar as a mitigation strategy, the uncertainties outlined above need to be resolved with some urgency.

20 billion Population sustainable

When I started his blog, my central thesis was that the global need to reorganize the way we handled CO2, called for nothing less than the terra forming of the Earth. My central tool was the establishment of a well planned global silviculture support system. This was because agriculture and forest management are close enough that it is possible to establish mutual support.

What our investigation has brought home is that our tool kit is much better than anyone imagined and even more invasive than anyone imagined. And I mean invasive in a good manner. We can often help mother nature to maximize results.

The core economic unit is still the private farm. Preferably the village farm, although the family farm will still be important.

I have discussed the need to tie our civilization more directly to our agricultural roots. This will mean that a farm unit needs to be integrated with a condominium tower containing a couple hundred families with rapid access to the urban job market. This supplies the farm with a ready supply of temporary labor as needed to take advantage of higher yield crops and supply labor intensive maintenance.

A single family can operate a thousand acre $200 gross per grain farm. That same family could just as easily operate a high yielding crop worth several times as much on a fraction of the land. Somewhere in between there is an agricultural coop type system as used for centuries in Europe in which all labor was honored and valuable.

The point that I want to make is that part time labor must be available if we hope to harness the potential that we are describing in these posts. And it has to be welcome labor respecting a person's time and place in life and honoring his input. This problem has been well solved in the past, but has been forgotten in the rush to the family farm and the industrial farm.

Our hypothetical farm unit today can be built around several new virtuous cycles.

1 The terra preta - corn culture builds soils and restores full fertility while permanently sequestering one ton per acre of carbon per year.

2 Woodlot management produces forest products and a steady stream of waste wood chips while building up to 25 to 50 tons of sequestered carbon per year. The wood chips make a good feedstock for methanol production, but not as likely for biochar since it requires grinding.

3 Cattle culture produces a waste stream that may now be diverted into algae production. This will produce an oil byproduct that makes good biodiesel and a solid byproduct that may either be used as cattle feed or used in fermentation or both. That is still a speculation, but something like this seems possible. It would be clearly superior to prior practice which has always been unsatisfactory.

4 Atmospheric water production will open up progressively the earth's arid lands. I say progressively since it is all about growing trees that then dump the moisture back into the atmosphere for reuse. The same rainfall can theoretically water the Sahara desert over and over again. Of course it is not that simple and will require progressive tweaking even when the cost of the technology has become cheaper than needed.

5 Woodlot management that produces economic amounts of forest products and also a viable fuel will progressively convert the wildwood into viable farm units, even in the rainforests. Good management will become possible even while maximizing diversity. Again, the main challenge is to eliminate short term exploitation tenures. And the best way to do that is to do that is to tax the resource through a long term partnership that demands a sustained species mix. It is pretty hard to cut all the oak if you are going to be taxed in perpetuity for those non existent oaks at current market value. Inflation alone will bankrupt such a practitioner eventually.

6 Proper wildlife husbandry is completely feasible and needs only the establishment of proper ownership to bring under effective management.

The main business of mankind is to produce enough food and now, enough fuel through sustainable sources. These protocols make a global population of even 20 billion possible and sustainable.

Early Terra Preta Production

As my long time blog readers know, terra preta is a man made soil located in the Amazon by the Indians up to the time of the conquest for at least a thousand years. Besides the substantial 15% content of powdered charcoal we have an additional persuasive content of apparent broken pottery shards throughout.

The Indians were able to produce powdered charcoal while consuming a lot of low grade pottery in the process. This is many tons of charcoal per acre. The manufactured soil retains fertility without significant assistance in an environment were its only competitor is low productivity slash and burn. High density settlement resulted and was almost certainly responsible for the legends of El Dorado. The Spaniards were about a generation too late and the knowledge was lost.]

Reconstructing the production protocol was tricky but is is really very simple.

It was and still is impossible to use wood economically to produce the powdered charcoal. I say impossible because the direct costs of harvesting wood is well known and the cost of producing charcoal is also well known. That implies that wood charcoal which also has to be fine ground must have a cost base approaching that of sawn wood. The sunk cost is far too high to ever use as a soil additive. This is borne out even in Africa were we see charcoal been made to take advantage of its direct cash value as fuel.

That leaves us with dry crop residue as a source material and a very productive one to boot. In the time and place, and this is almost still true today, the only crop that fitted the volume need to make the process practical is and was corn. Today bagasse could also be used. The important factor is tonnage per acre. Corn is good for ten tons per acre. Most other crops simply fail to produce enough plant material. Additionally, corn waste or stover must be removed and burned regardless.

Since it must be gathered and burned in any event, the question is how to convert this feedstock into a ton or two of powdered charcoal or more reasonably into biochar retaining both the charcoal content and some remaining plant material.

Here, the nature of the corn root itself helps out hugely. It form a flat disc, not unlike the base of a floor lamp. This dirt ball can be treated almost like a brick. It permits the building of tightly packed stacks whose outer wall is formed be tightly packed root discs loaded with mud. It is no big trick to build a vertical wall of these root discs to act as the outer shell of what is a temporary earthen kiln. It was actually a brilliant innovation by some Indian a couple of thousands of years ago.

This earthen kiln is then fired by the process of dumping a charge of glowing wood coals on the top of the stack, directly into the packed dry corn stalks, and covering it immediately with the sun dried earthen platter that carried the coals. You would then cover the top with additional dirt to maintain the integrity of the earthen kiln and let the coals do their work.

The coals will drive a chimney into the stack and all the combustion will take place inside the covered chimney. This nicely minimizes any unnecessary energy loss and maximizes combustion which goes into reducing the balance of the stover. The earthen wall even filters out any errant heavy gases as they try to escape. I suspect that it is only with the recycled gas systems of today that we can do better.

This task would be done after the corn had fully ripened and dehydrated which occurs just after harvest. The corn stalks dry out then and are still pretty impervious to wetting by rain.

Once the burn is complete the next day, one would rake out any unburned roots to throw into the next kiln and then take baskets of the soil - charcoal mixture back into the field to produce the hills for the next crop. The only tool used would be the earthen ware pottery and a strong back. Today I would use a metal garbage can lid.

This process produces enough material to salvage the field in tropical conditions for an immediate crop during the next season. Once this was understood, it became practice and was intensively employed long past its actual necessity for many thousands of acres in the Amazon.

When I first made this hypothesis on the likely protocol, I did a literature search of the Archeological data on the Terra Preta soils looking for the pollen data. Remember that corn is not your first choice of a crop plant on a rain forest soil. I was gratified to discover that the two principal crops were corn and cassava which also produces a lot of biomass but no usable root ball. This confirmed that the protocol had legs.

I am quite prepared to work with someone who wishes to run field tests at no charge since I personally think that this will revolutionize all subsistence farming generally as they can be the first adopters. Larger acreages will need kiln equipment at the least and this will be capital intensive.

And it would be great to get this going where the crop cycle is currently multiple years through slash and burn. I think particularly of the Philippines were I have had fifteen year fallow periods reported. The same must be true for a lot of land in Africa and elsewhere. The more interesting question is the fertility increases in soils now been exploited.

Real Winter and corn biochar culture

It appears that we are going to have a real winter this year, at least of the basis of what we are getting so far. All Canada is showing temperatures below normal for this time of the year and we are getting plenty of snow. We certainly were overdue.

Since it kicked in fully with the beginning of December, it is likely to maintain itself right through January. This means that the pine beetle infestation should end in Northern British Columbia. We shall see.

A good cold winter will stress test our ideas about the Arctic sea ice. It will make watching the ice retreat next summer much more interesting. Remember that sixty percent of perennial ice was lost between 1957 and 2000 during a time in which we barely noticed that the climate was a touch warmer. In fact the pine beetles only noticed it ten years ago.

I suspect that since 2000, we have lost more than half of the remaining perennial sea ice and that the balance can readily disappear in the next seven years. The question for this summer is whether the unusual wind system of the past two summers will kick in. A cold winter may negate it for now.

What is important in the long term is the elimination of the perennial sea ice as an Arctic climate control factor. Once it is gone, the summer Boreal winds will sweep the Arctic clear every year much sooner than late august and will open the Arctic to shipping.

A direct result of this will be a two degree rise in temperatures for Northern Europe and the restoration of Bronze Age climatic conditions. We will be growing grapes in England after all. And no one will have any difficulty placing the world of Ulysses in the Baltic.

A cold winter will have little effect on the loss of sea ice, although a late spring certainly will. We certainly did not have an early fall, so we will have to wait and see what the spring holds for us. I am expecting a neutral year in which the ice loss is normal if that is at all possible in view of the massive loss of perennial sea ice and the newly resurrected Boreal winds.

Did you ever wonder why the Boreal winds were an important part of Nordic folk lore? I think that we are about to find out.

I would like to thank Nicole for her comment on the last post. She posts the information that we have put 200 plus billion tons of carbon in the atmosphere while we manage about 24 billion tons in depleted agricultural soils. This says quite nicely that agriculture needs to sequester ten times the carbon currently utilized.

Those who have waded through my many posts on the subject know that is completely feasible using the terra preta protocol.

Otherwise, although I am very sympathetic to the attempts to take advantage of pyrolysis and perhaps high pressure reforming to produce a fuel and a char byproduct, I am not overly optimistic. It also requires expensive engineering and fabrication to achieve the demanded perfection ensuring that it will never be properly deployed.

I am also not so sure that high temperature charcoal is as beneficial as mid temperature biochar as produced by terra preta techniques. In any event, a corn based protocol will certainly produce a biochar that is already powdered and is likely in the best form for agricultural application. And it is a ton per acre which is ample to meet our needs. It becomes theoretically possible to clean up the problem in even a couple of generations while hugely increasing agricultural productivity.

The question is also asked indirectly why is charcoal not prevalent in slash and burn soils and in areas that man has cleared and converted to farmland. The reason is simple enough. Hot charcoal will spontaneously ignite, so unless there is intervention to shut off the air supply with a shovel full of dirt it will all burn off. This is what makes the earthen kiln built from the roots of corn so effective. As the fuel is consumed, the stack with its earthen shell will shrink and any breakouts can be quenched with a basket of dirt.

Such a kiln should yield around 20% plus charcoal as biochar while reducing the balance to CO2. The powdered carbon is then folded back into the soil and is sequestered as the terra preta soils have proven beyond any doubt.

The original question that I faced was how did they do it. I have demonstrated how they did it and the archaeological evidence conforms it totally. In fact when I worked this all out, I predicted that it had to be by the use of corn as it was the only crop available that was both productive enough and also assisted in the building of a kiln. It was with some satisfaction that I was able to check archaeological pollen tests and confirm that the two principal crops were corn and cassava. And it is also worth noting that corn is not a great crop normally for Amazonian conditions so they had to have a compelling reason to grow it at all.

The point of all this is that the worlds 2 billion plus subsistence farmers can readily implement terra preta corn culture anywhere, including massive tracts of long cycle slash and burn agricultural lands and create new productive lives for themselves while sequestering all the worlds carbon.

Any system that converts annual biomass into terra preta biochar is massively carbon friendly and needs to be promoted, although I am sure an army of mental midgets will scream exploitation of the masses, just as they try to argue that no job is superior to a steady job that feeds the whole family. Forgive my impatience.

Natural genius of Brazil's Indians

The more I discuss and pull apart the concept of the corn stover bio char production system, the more that I come to admire the achievement of these so called primitives. As my readers know, large areas of Brazil's tropical soils were made continuously fertile by the addition of many tons of low temperature charcoal or biochar per acre. This is carbon sequestration by any other name and is called terra preta.

I recognized that the only crop that lent itself easily to the charing process was corn. It produced ten tons of dry unusable waste for every acre which could produce at least a ton of char per acre. This is more than enough to visibly impact fertility. On top of that, the crop husbandry system was all about hills, so that the char was delivered directly to the hill and not to the 75% of the field kept fallow between the hills. It sounds like a basket full to me.

A review of the literature revealed that corn pollen and cassava pollen were in fact the principle crops. Cassava also produces a great deal of biomass and would nicely augment any Biochar production protocol, although I have never emphasized it.

I then recognized, from personal experience that corn had one unique characteristic that hugely accommodated the production of Biochar. Corn produces a horizontal root pad that is easily pulled out of the soil. This brick like root ball is a natural brick that permits the building of an earthen shell that could form the near vertical walls of an earthen kiln. This is hugely important, because it eliminates the need to dig a huge pit or to build a large soil bank. It can also be built anywhere and sized to the most efficient design possible.

Any piece of jungle can be burned out and with a first corn crop, terra preta can be established. Constant repetition will easily build up the carbon content to the 15% charcoal level inside a couple of generations, while preserving soil fertility.

There is also very little additional labor required, an awfully important consideration in a ulture that had no draft animals.

Once the stack is built in whatever shape works best through experience and discussed earlier, It is necessary to throw a layer of dirt on the flat top of the stack, to effect final closure. We end up with a complete dirt shell surrounding tightly packed corn stalks with a packing ratio of at least 70%.

Now comes the problem of ignition. My conjecture is that they opened a chimney in the center of the pile by pushing the dirt aside. They then dumped in a large charge of glowing coals from a wood fire held in a earthenware platter, which was then tipped over and used to cap the coals and prevent flaming. This was then covered with the displaced dirt.

And this is were the genius of the Indians really comes in. As the coal mass ate its way down through the bio mass, it drew a steady controlled stream of air in through the earthen walls and sustaining the burn. But as the burn progressed, the plate forced the process gases initially away from the chimney in back through the smoldering wall of the chimney before it finally exits through the chimney. A constant supply of fresh dirt to cover any breakouts should maintain a steady burn.

Without field trials, we seem to have a method that produces biochar by burning the process gas very completely and getting the maximum heat.

I am convinced that with a little practice, any family can produce biochar at a very high level of efficiency. This method will end slash and burn agricultural as still practiced in the tropics.

The modern farmer will want to use a closed incinerator with a double lung design to capture the maximum heat and to produce the cleanest exhaust gas. This is very capital intensive if done properly even if using the shipping container system previously aired.

I wonder what we will learn when field tests are done to compare the two systems?

All I am sure about is that the elimination of slash and burn with an annual earthen kiln system on perhaps 20% of the arable land in the tropics is a vast improvement over what passes for current practice. It will also increase the amount of continuously cropped land by orders of magnitude. To say absolutely nothing about fertility enhancement on established fields.

Traditional agriculture has beggered millions for generations. This can now change completely.

Biochar Packing Strategies

In my last post, we arrived at the conclusion that the one key crop that can make biochar production feasible for agriculture is corn. It is also apparent that a naturally built stack without much work will produce some biochar, certainly enough for the owner to recognize the value of the product and to want to improve his efficiency.

The first need is to develop an earthen kiln strategy that can hugely increase production. shoveling dirt is an option, but likely very unsatisfactory, difficult to control during the burn, and very labor intensive. Digging a pit can perhaps help improve this situation and may have been a viable option. however, the average pit needs to contain ten tons of material and a typical five acre field will need several pits. This requires an incredible amount of additional labor to execute properly. So although suitable for pottery making, It is a much less practical approach with field operations. And we still have to pay attention to packing.

This is were my understanding of the nature of the corn root ball led me to the conclusion that much more sophisticated packing strategies were available to the farmer that hugely lowered the labor needed to move dirt. The corn root ball consists of a poorly rooted flat disc sitting on the top of the soil. Penetration is less than three inches, while the disc itself is several inches across. It is easily lifted in most soils by the simple expedient of grabbing the stalk and pulling.

We suddenly have a packable source of biochar with its own contribution to the earthen wall attached. What was the farmer waiting for? The remaining question is how best to pack the stalks and to simultaneously build the outer wall of the earthen kiln. So far I have imagined several packing strategies that could work, although they all have to be tested.

But I think that we can all agree that a stalk of biomass with a brick attached is a great start. As good as a box of Leggo.

I see two strategies. One in which a windrow is build with one side forming an earthen wall. Remember that in order to achieve tight packing it will be necessary to overlap the root balls at least three deep creating a mud wall several inches thick. They may also have packed other material among the stalks to improve packing. I think that Cassava is particularly suitable.

A second windrow can then be build against the first windrow on the non walled side. This then still leaves you with the task of covering the exposed stalks with dirt but primarily unto a flat surface. Any type of variation of this packing approach should work very well.

The second strategy is to lay out a 12X12 square and lay in packed layers at right angels to each other with the earthen wall on the outside. We end up with a well packed interior and an outside earthen wall perhaps several feet high completely surrounding the material.. A thin layer of dirt on the top of this stack will then close the kiln.

This is obviously the most attractive approach provided the packing ratio can be maintained.

In all cases, the burn is initiated by carrying an earthenware platter (unfired) full of glowing coals unto the top of the heap, dumping them unto the stalks and then tipping the platter on top of the coals as a shield, and then covering it all with dirt. A crew then watches the heap for breakouts, in order to throw extra dirt as needed.

Observe that we have minimized the labor input throughout. A lot of extra time will be spent of getting the packing right, but that is not onerous. Building a layer of dirt onto the top of the 12X12 heap will move perhaps a ton of dirt which will mix nicely with the ton or two of produced biochar. This is not unreasonable. The produced biochar and dirt mixture can be then carried in baskets back to field to renew the seed hills in time for the next crop.

The point that I would like to make here is that this protocol allowed the ancient farmer to have his terra preta soil immediately and made corn culture possible in tropical soils as proven by pollen analysis. There was no multi season delay in establishing terra preta.

And rather obviously, the same approach today can revolutionize indigenous agriculture globally. And rather obviously also, there is no particular need to do most field once it has been done at least once. The carbon continues to hold nutrients for a very long time.

From the perspective of sequestering carbon, we want this done twenty to fifty times. From the perspective of building a viable soil base, several times should be more than ample.

You realize folks, that this is a total and unexpected revolution in agriculture that can increase agricultural production globally by even an order of magnitude.

All depleted soils can be put back on line everywhere, and the unusable tropical soils can achieve year round high volume production.

And we were only trying to sequester CO2

Developing biochar protocols

In reviewing my posts on terra preta and the comments since generated by the expanded participation around the terra preta website in particular, I realize that this is a good time to share with everyone the thought processes that led to the corn culture hypothesis. This will also serve to air my response to the many nagging questions that I see recurring on the site.

I proceeded by developing my understanding of the constraints under which the farmers operated and investigating possible solutions. This approach should also inform other researchers looking at alternative solutions which may be out there.

It is fairly trivial to determine the time and place that the original terra preta soils were created. Archeology has pushed the time line back to 2500 years ago and to as recently as 500 years ago. It was clearly linked to an agricultural civilization with all the archaeological evidence lined up behind it. Although The apparent beginning coincided with the late European Bronze Age, I an unaware of any Archaeological evidence to suggest that we are dealing with a technology level that was any thing other than late stone age. That could still imply very limited access to some copper tools but nothing that would likely leak into the agricultural economy. Even the late European Bronze age I suspect had trouble using their only form of portable wealth to help their farmers.

So we can be fairly sure that our farmer worked with what tools could be made out of wood and stone. This is sufficient to girdle trees and to painfully do some wood cutting. So slash and burn becomes practical as does a limited wood processing industry. My best informant on this is the eighteenth century state of woodworking on the Pacific Northwest which then blossomed into the artistic explosion we know with the advent of steel axes. Cutting and splitting wood was possible but clearly not easy.

I then investigated traditional open air charcoal making which deforested much of the Eastern woodlands in the nineteenth century. Nothing like checking with the real experts who were relying on a thousand year old tradition. What is immediately evident, is that high yield charcoal making in open air is dependent on limiting air flow through the maximizing of packing ratio and the uniformity of that ratio. This is perhaps obvious but the fact that the packing ratio needs to be better than 75% is not obvious.

Packing ratio is a mathematical concept that measures the amount of open space to solid as a ratio. For example, a bucket of balls has a best packing ratio of 51%. This is not obvious.

Cutting hardwood to length and splitting out four inch blocks, which are then tight packed achieves both a 75% plus packing ratio but also good heat circulation. This is why the high yields were achieved.

To replicate the same packing ratio and heat transport with any biomass is a tall order. Most biomass is often almost unpackable, such as woodland waste or any branched crop. The simple jumbling together of waste ensures a lousy packing ratio and heat transport problems. In fact, it is fair to say that charcoaling woodland waste was also not very convenient without steel tools to cut the wood to length to get the needed packing ratio.

Once one realizes that the jungle is not a viable source for high volume ongoing biochar production, one must retreat to their crops. Recall that these fields are created first by the process of slash and burn which produces only a little charcoal which likely burns in the next cycle of slash and burn.

Again the packing ratio has a lot to say. Most of the burn happens just on the ground or above it. There is a lot less heat penetration of the soil than you would suppose. Recent comments on prairie grass misses this effect, since prairie grass has a packing ratio of possibly less than 20%, most of the heat is dumped into the atmosphere. I learned this lesson by attempting to roast a potato under a mound of better fuel than prairie grass. (the neighbors all came out to see the 'barn' burn:)).

If we want to produce biochar at all we have to grow the feedstock and then tightly pack it in order to get the necessary conditions in place. This limits us quickly to stalk plants that have a natural theoretical packing ratio of 77%.

Most grain crops seem to lend themselves to this except for their low volume on a per acre basis. Modern crops such as sugar cane would be possible if we did not use the cane. some other plants can be obviously used in this way. However, we very quickly are forced to consider corn simply because its non edible part consisting of the stalk represents a ten ton per acre source of biomass and a potential one to two ton source of char per acre.

This very high per acre yield is very necessary to the farmer because he has to see that he is visibly changing the seed bed and not expending a huge effort on haulage. Even today, this is the one crop producing enough bio mass to make terra preta practical.

The antique farmer had a waste product that he had to pull out of the ground and build into a waste stack to begin with so that he could raise the next crop. It was a likely ten ton stack since that was as far as he wished to haul this material. He then simply burned it as farmers do to this day. Even without proper packing some char was produced. It was not a big leap to optimize the packing and eventually to optimize the biochar production from this base.

I had reached these conclusions before I queried google scholar and ran down the pollen profile of the terra preta soils which immediately confirmed the predominance of corn pollen. Cassava also showed up which is also suitable for packing.

I will develop the rest of the story in my next post, but it can be found piecemeal in my earlier posts.

New Age Global Agriculture

When I started this blog, I had one very important arrow in my quiver. That was the knowledge that it was becoming feasible to produce a small stand alone solar atmospheric water harvesting device capable of daily producing a 100 liters of water per day.

This would be sufficient to support a growing tree in any arid desert were the humidity was high enough. Of course that means all deserts since one would start at the humid rim and slowly advance into the desert effectively bringing the natural humidity with you. This terra forming of the desert would naturally support a cropland fraction and an extensive animal husbandry among the trees and orchards.

We can easily globally double the available land under agricultural management in this way and sequester a huge amount of carbon.

I then extended this approach to current agricultural practice and developed an economic model for bringing agricultural waste land under managed forest practice were atmospheric water harvesting is less important.

An underlying assumption for both approaches was that current practice would not be modified very quickly and that no good solutions for soil improvement were at hand. But we could live with that since we had done so for thousands of years. I was still very uncomfortable though that we were mining the soil for nutrients and that replacement strategies consisted of mining and producing minerals often in a non sustainable manner.

This also meant that desert lands would require long periods of time to reconstitute soils. Trees would be fine because they reach deep into the earth to find nutrients, but the surface would suffer. Again time and careful effort would overcome all this. A thousand years of effort and every hillside and former dry land could be fully timbered and vegetated with modest final water inputs. This is a fine dream and project for humanity to embark upon.

And then I was introduced to Terra preta. This was work that conformed to and confirmed a previous effort that I had put into Zeolites in which a great deal of field work has been done by researchers. I understood immediately the importance to the globe of this discovery. The problem was to figure out how to produce the soil.

This I was able to tentatively solve through the use of an infield carefully constructed corn stover stack kiln that would produce a ton of biochar per acre.

All of a sudden we have a method of swiftly building out soils anywhere in the world.

Let us engage in a thought experiment. Keep in mind that we cannot quite do this yet. We take a square mile of desert fairly close to adjacent agricultural land. We isolate the low lying areas (perhaps a 100 acres) as potential crop land toward which surplus water will flow. We plant tree cover with solar water harvesting devices outside these areas.

As the trees grow out, the soils begin to build up some water retention and this supports an increase in ground water finding its way into the designated crop lands. As soon as feasible we start the first corn crop. Each crop puts a ton of biochar back into the soil and several years of this attention we should have well developed soil. At that point, we continue to produce biochar which is then transported into the woodlands an integrated into those soils accelerating their maturing. If we are already running cattle, we will witness a rapid improvement in available fodder.

If the objective is to create mature soils throughout and to achieve maximum yield throughout, then at the end of fifty years every acre should have several tons of carbon in the form of char and additional living carbon totaling another twenty tons or so. This can all be done in the lifetime of an individual owner.

This is a far cry from the current situation in which we are running fast just to stay even.

Global Corn Culture

I have become progressively more comfortable with the production of biochar using some form of corn stack. As each new issue is addressed, the genius of the Amazonian Indians becomes more apparent and appreciated. The difficulties of providing a mechanical assist also seem readily surmountable.

I am far less comfortable using various oven designs and pressure chamber converters to achieve largely the same end with a marginally better yield, yet with an order of magnitude jump in handling costs. My best design concept of the two lung incinerator, while maximizing yield will also demand to be fed year round in order to be possibly economic. And that also applies to pyrolyzers and the like. This means that a minimal 1000 ton per day operation will require at least a 1000 square miles of supply area and all the trucking that goes with that. Tom Miles is certainly not wrong on this.

My single farm modified container will only operate for around a month during the appropriate season and very little in between. It must be cheap and I do not know if that will actually be achievable. The second lung and its controls could turn out to be commercially crippling, principally because an expensive high grade fire brick must be used.

I keep coming back to the simplicity of carefully field stacking corn stover to produce the biochar. We know that this will yield a mix of char and soil representing a twenty percent yield with only a small increase in handling effort. With equipment we can actually build windrows, even driving on top of them to compact the stack properly before covering with dirt and igniting.

The only drawback, which seems to make some folks hysterical is that we lose the volatiles into the atmosphere. Most of this is CO2, while the rest is in the form of a wide range of organic molecules, similar to that produced from a forest fire or slash and burn agriculture. The heavy end falls back onto the soil, while the lights are typically degraded sooner or later in the upper atmosphere. Methane and probably ethane even end up in the troposphere above our atmospheric circulation system.

Unlike forest fires and their like, this process sequesters a great deal of carbon. Which returns us to the whole point of the exercise. Adding charcoal to the soil appears to vastly improve and stabilize the majority of soils. Right now we do not know were it does not work.

This is because charcoal is a strong acid, yet is insoluble. That allows it to grab nutrients year after year and recycle them back to the plants. A minimum amount of maintenance ensures maximal fertility anywhere once the initial effort is made to create the soils.

I suspect that, while terra preta soil manufacturing was the dominant culture in the Amazon, that there is no reason for it to be a continuously applied system in most soils. After all we know that a season's corn production will generate around a ton of charcoal per acre which is actually a lot already. Fifty tons per acre is likely the maximum that you would ever want in the soil.

Thus doing corn with terra preta in normal field rotation is very plausible everywhere. Europe and North America are the most glaring examples that I am familiar with, and I am very sure that this will be another green revolution in both India and China. Fifty years of effort and all crop lands will be well on the way to be terra preta soils and their permanent fertility will be secure. I can tell you that from a farmers perspective, that this is almost too good to be true. Fertility has been foremost on their thoughts forever.

Even more exciting, this looks like a method to restore fertility in despoiled lands were past practice has destroyed fertility and with it the soil's water holding ability. Mesopotamia particularly leaps to mind. Why should the Garden of Eden be covered with blowing salt ladened dust and treeless hillsides.

I am hopeful that the simple restoration of irrigation, can allow a corn crop to be nursed into full growth. Remember that the root practically lies on the surface, so working the top three inches of soil with biochar should quickly restore these soils. The important question is whether the charcoal will progressively sequester the salts and as a result to gently sweeten the soils. If it does not, there are still practical options because of the soil improvement brought on. They will simply take longer to have effect.