[Terrapreta] Biochar Packing Strategies

[Robert Klein]

In my last post, 

http://globalwarming-arclein.blogspot.com/2007/09/developing-biochar-protocols.html

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



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