[Terrapreta] Critical thinking (continued)

[Richard Haard]

Thanks Jim Joyce but let me take this thread on a different tangent

Along the lines of Kurts' posting but leaving that straw man stuff  
alone  - Just why is it are we here at terrapreta at bioenergylists?  
Discussing terra preta and the use of charcoal in soil. And also  
having a good ole time writing about and discussing topics that are  
related to this topic. This is a nice community of people and we are  
diverse in our viewpoints. There are times I need to restrain myself  
from being reactionary about something I feel very strongly about. Yet  
we need to encourage participants to express their diverse viewpoints.  
Because it is diversity that gets me thinking.

My own thoughts are now going back to the humid tropics, the high  
rainfall and Ferralsols and Acrisols that are extremely difficult to  
farm the way we grow crops in the temperate north. This is because  
soil organic matter at the heart of plant nutrition is rapidly  
oxidized also the extreme rainfall leaches the nitrogen and well as  
soil conditions that tie up phosphorus. Farming in the humid tropics  
is practiced by 300 to 500 million peoples and involves 1500 million  
ha of land yet this system of cultivation slash and burn (shifting  
cultivation) involves long periods of fallow to restore soil organic  
matter after relatively short periods of fertile production. These  
productive periods can be extended somewhat by dependence on chemical  
fertilizer but eventually the organic matter issue will end this  
expensive workaround.

Yet the anthropogenic carbon rich dark soils that are related to these  
Ferralsols and other native soils seemingly have the unique   
characteristic of stable soil organic matter either  as mimicked  
organic matter or somehow enabled by ' black C as charcoal'.  
Associated also with this charcoal is a presence of calcium and  
available phosphorus not found in the virgin soils. Thus somehow these  
soils have become fertile, respond to shorter fallow periods, and  
normal treatments with compost, manure or fertilizer in ways that more  
closely resemble the productive farmlands further north.

Yet here we are again learning of our friend Nikolaus Foldi and his  
struggle to learn to correctly use charcoal on his Bolivian fields.  
Also we are learning further that this massive clearing of rainforest  
is stimulated by global demand for soy and corn and that this presence  
of  agriculture itself tends to bring about an increase in population,  
as others have written about (read My Ishmael by Daniel Quinn).  
Further the Brazilian government  is admitting failure in their  
attempts to limit further clearing of forest land and we are in a  
positive feedback loop where more land in these humid tropics needs to  
be cleared in order to maintain enough production to financially  
support the farmers who are giving their income to the  
chemical,fertilizer companies and global grain conglomerates to  
support declining production on land that should be going back to  
forest.

We also learn that in the clearing and burning process a mere 1.7% of  
the pre-burn forest biomass is converted to carbon. According to  Dr  
Lehmann's  (with Marco Rondon) paper ' Bio-char soil management on  
highly weathered soils in the humid tropics ' (available at his  
Cornell website) we have confirmation that organic additives to these  
tropical soils are rapidly converted to CO2 and their recommendation  
to mitigate for this problem we need to promote and refine a new kind  
of agriculture not slash and burn but slash and char.  Now just what  
is this slash and char? Is this system of agriculture only for the  
small holding farmer or can industrial agriculture adapt this  
technique to make farming and food production sustainable in the moist  
tropics? This latter question I am fearful the answer is no but  
Nikolaus and others need to continue their work on answering this  
question.

To learn more about what this slash and char is I downloaded Dr.  
Christoph Steiners dissertation from the publisher , Cullier Verlag. I  
had this treatise  of his and colleagues work on my hard-drive in a  
few minutes at a cost of a mere 9.08 euros. This book  'Slash and Char  
an Alternative to Slash and Burn' is a very good study topic that I am  
just now beginning to go over in detail. The book includes field,  
greenhouse and laboratory controlled studies, information about local  
charcoal production methods, and indigenous soil management  
techniques. All aspects of this book present materials, information  
and perspectives that would be beneficial to our conversations at least.

Troubling to me is the unitary feature of charcoal production wherever  
we find it - the higher value of the product as a cash commodity than  
as a soil conditioner. This is an economic decision by the farmer (if  
he is the charcoal producer) to sell the charcoal for cash, to only  
spread the fines on his fields and to use his money to buy fertilizer  
and pesticides. It is also difficult and expensive for him because he  
must gather the wood or agricultural debris, transport it to his kiln  
and bring it back to his field.

The only way I can see out of this loop is to make the charcoal in or  
very close to the field and very much like cover cropping turn  
everything into the ground. This also allows the soil to receive the  
benefits of what Steiner has reported of the direct effects of burning  
on the soil and of smoke and associated pyroligneous acid on  
stimulating soil microbial activity. Confirmed not only by his studies  
but also by his analysis of local indigenous farming techniques.

Therefore with on-farm and direct conversion to char by smoldering,  
smothered , and wet combustion we will have a maximum return of carbon  
to the soil. It does make lots of smoke but you know we have a high  
return of the carbon to the soil hence the sequestration takes care of  
itself. The smoke itself also treats the soil and is actually part of  
the process. There is absolutely no reason at all to even try to  
completely carbonize the wood. Here is an image of partially charred  
wood with rotted wood in the center serving as habitat for beneficial  
microorganisms. In land clearing as larger tract a farmer such as  
Nikolaus would need to make smaller piles and fires rather than drying  
and heaping the forest debris for a complete burn. He would then  
smother the fires and later sort out the unburned wood for later fires  
in the same place. This way as much as 40 % or more of the forest  
biomass would be converted to charcoal rather than the meager 1.7%.  
Labor intensive yes, lots of smoke, yes but closer to the original  
methods of the indigenous predecessors. If he tells us this cannot be  
done then perhaps in the long run this kind of industrial agriculture  
in the moist tropics is not feasible.

A machine to make charcoal costing hundreds of thousands, or in some  
remote place may be what we need to do in urban centers with air  
quality standards. Use of this charcoal in agriculture without heavy  
subsidy may be an economic folly at least until we have gone through  
some sort of peak energy paradigm shift. In the humid tropics however,  
the place where those 300 to 500 million peoples (and growing) are in  
South America, Africa, and the humid tropics of Asia on their small  
holding farms is where appropriate scale/technique slash and char  
needs to be perfected. It is an interesting and an academic topic for  
us fortunate farmers whose soils stay at 4% easily and it's glacial  
origin gives us bottomless calcium and potassium nutrition. It is a  
matter of human survival for the tropical farmer trapped in the loop  
of declining production and a choice of dealing with 'the devil' for  
costly fertilizer and pesticide or clearing more land.

These people need to break this cycle. We know now that in these  
unregulated areas government cannot by policy determine that land  
clearing and illegal logging be stopped. Governments also by policy  
are encouraging this indiscriminate clearing of the land for purpose  
of generating export income and are inviting colonists to do this  
causing human right and property disputes with indigenous people. My  
beginning to make a survey of NGO's the privately supported and local  
interest groups are seemingly at the same impasse. Their focus also is  
only on stopping loss of forest habitat and promoting sustainable  
forestry practices when in reality soybeans ( or oil palm) are the  
true end use - so that we can feel good about driving our diesel SUV  
up here.

We are at a conceptual frontier, a slash and char frontier that has  
been shown to us by Dr Wim Sombrock , the father of this field, who  
championed the study of Amazon Dark soils, and by Johannes Lehmann who  
gave us this over the horizon vision that if we do convert our use of  
land in the humid tropics we can offset as much as 12% of global  
carbon atmospheric pollution. And the Asian scientists and farmers who  
independently learned of the value of charcoal in soil and the other  
scientists and their students who continue this work.

We do need to bring this realization of potential to governments and  
to NGO's and educate sources of private funding on the potential for  
slash and char as the best way to slow and stop this indiscriminate  
habitat destruction in the humid tropics. We need prescriptions of  
best agricultural practices for small holders. We need people in the  
field running workshops for farmers on slash and char.

For the industrial farmers in the moist  tropics we need a system of  
certification that biofuel feedstock  produced in the moist tropics is  
produced with a net gain of energy and reduction of CO2 emissions. In  
this way large scale farmers can receive a premium for their product  
for sustainable practices just as Starbucks now rewards coffee  
producers.

Best Wishes for black soils everywhere

Rich Haard















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