[Terrapreta] Pottery Shards and Terra Preta

[Kevin Chisholm]

Dear Lou

Thanks for your comments.
lou gold wrote:
> Kevin,
>
> The video simply showed what they found in terra preta soils, layer 
> after layer of pottery. The interest was in showing that TP was 
> man-made, pottery being the evidence. Because they said that pottery 
> was found in EVERY place of TP, it is reasonable also to think it 
> played some role in the process. The BBC documentary simply said that 
> analysis showed the presence of pottery, charcoal and organic matter.
OK... Zeolites are known for their ability to enhance CEC, as is also 
clay. Is it possible that the clay shards were acting as a CEC material 
also? For example, firing of the clay for pottery could indeed have 
activated it, so that it had the properties we attribute to char also... 
high internal surface area, microporosity, and CEC capacity.
>
> I don't know that this means that pottery is "essential" in making TP 
> in the chemical or biological sense.
We do know that "black earth" in temperate climates, with no pottery 
shards are highly productive. (eg, Holland Marsh near Toronto). Is it 
possible that pottery shards are not essential to TP, but the right kind 
of pottery shards could be very beneficial? One could imagine that a 
high fired clay, or a glazed pottery piece would be of little to no 
benefit to the soil, perhaps as unhelpful as a shard of glass.
> It might mean that the pottery was a container for another ingredient 
> that was essential to the process. I speculated that the "ingredient" 
> might have been human waste. If there were millions of people living 
> there, waste management would have been a serious challenge. An 
> integrated waste management system that recycled waste into TP 
> production would have been an interesting and feasible solution.

Very good points!! From a practical standpoint, would the Ancients use 
slop containers, OR would they have been more likely to have composted 
their human wastes, and then brought the composted wastes to the fields? 
Is there anyone on the List familiar with Night Soil Practises?
>
> The pottery was also found everywhere there was raised earth. 
When they talked about "growing Terra Preta", there was no mention of 
pottery chard additions. Additionally, when the TP that was being 
shovelled onto truchs was observed, there was no indication of pottery 
shards being present.
> They showed it as especially dense in areas of mound building. Perhaps 
> this was structural, giving a "foundation" in the ground, helping to 
> prevent erosion, etc.
Another good point. The entire area seemed devoid of rock. If nothing 
else, the pottery shards could have acted as armour to prevent rain 
erosion until rooted vegetation took hold.

A fascinating problem indeed!!
>
> I'm only speculating.
Et tu, Brute? :-)

Best wishes,

Kevin
>
> lou
>
>
>
> On Dec 11, 2007 3:18 AM, Kevin Chisholm <kchisholm at ca.inter.net 
> <mailto:kchisholm at ca.inter.net>> wrote:
>
>     Dear Lou
>
>     lou gold wrote:
>     > Kevin,
>     >
>     > I don't know if you watched the BBC video, "The Secret of El
>     Dorado"?
>     > It shows the pottery dramatically, in layers deep into the soil.
>     >
>     http://video.google.com/videoplay?docid=-2809044795781727003&q=secret+of+el+dorado&total=21&start=0&num=10&so=0&type=search&plindex=0
>     <http://video.google.com/videoplay?docid=-2809044795781727003&q=secret+of+el+dorado&total=21&start=0&num=10&so=0&type=search&plindex=0>
>     >
>     <http://video.google.com/videoplay?docid=-2809044795781727003&q=secret+of+el+dorado&total=21&start=0&num=10&so=0&type=search&plindex=0
>     <http://video.google.com/videoplay?docid=-2809044795781727003&q=secret+of+el+dorado&total=21&start=0&num=10&so=0&type=search&plindex=0>>
>     >
>     I watched the video. I might have missed something, but I didn't see
>     anything that was suggestive that pottery was an essential
>     component of TP
>     > The pottery shards are suggestive to me. I speculate that the earth
>     > kilns used for making the pottery (loaded with lots of broken pieces
>     > from pottery making) became middens for human and organic wastes.
>     > Later as the whole "stew" ripen into TP, it could have been
>     transfered
>     > to the fields and also be useful structurally for creating
>     raised beds
>     > and preventing erosion under the heavy rains.
>     >
>     > What do you think?
>     I would think that there was some other process... the extent of
>     earthworks involved means that they would have had a methodical way to
>     proceed, and not rely simply on using their middens to reclaim and
>     protect land.
>
>     In one section of the video, where they were talking about "... TP is
>     mined and replaces itself in 20 years...", they clearly mention
>     that the
>     leaves from the nearby forest fill in where they mined, and the TP is
>     replaced. There is no mention of pottery shards in the process of
>     growing new TP.
>
>     I am wondering if TP formation was as simple as follows:
>     They build a raised bed with some charcoal or black earth
>     initially, and
>     with canals on both sides.
>     They plant crops.
>     They throw the vegetative waste from the crops into the water
>     channels
>     on both sides of the raised beds.
>     During dry season, they shovel the anaerobic decomposition products up
>     on to the raised bed, to build it higher.
>
>     This would seem to hang together.
>
>     What do you think?
>
>     Best wishes,
>
>     Kevin
>
>     >
>     > lou
>     >
>     >
>     >
>     >
>     >
>     > On Dec 10, 2007 5:09 PM, Kevin Chisholm <kchisholm at ca.inter.net
>     <mailto:kchisholm at ca.inter.net>
>     > <mailto:kchisholm at ca.inter.net <mailto:kchisholm at ca.inter.net>>>
>     wrote:
>     >
>     >     Some people hold that pottery shards are an important aspect
>     to the
>     >     working of Terra Preta, (TP) but others feel that the
>     presence of
>     >     pottery shards in Amazonian Dark Earths (ADE) is incidental
>     to the
>     >     performance of the TP.
>     >
>     >     Is it possible that the Researchers looked for the presence
>     of pottery
>     >     shards as a way of proving human involvement, and did most of
>     >     their work
>     >     on TP soils that had a human involvement?
>     >
>     >     Pottery was a big art of Brazilian Indian Culture, but other
>     Ancient
>     >     Cultures did not have, or made very little use, of pottery.
>     Are tehre
>     >     any "black earth" deposits outside "pottery cultures" that are
>     >     acknowledged as being the equivalent to TP?
>     >
>     >     Is it possible that there are many man made TP soils to which no
>     >     shards
>     >     were added?
>     >
>     >     What is the nature of the shards found in TP? Are they like
>     a crushed
>     >     grog, where it is obvious that effort had been expended
>     breaking the
>     >     pottery to relatively small pieces, OR, is shard size and
>     shape such
>     >     that it suggests broken pottery items were simply discarded?
>     >
>     >     Are the shards of a nature in size and completeness that
>     they could be
>     >     re-assembled to reveal the size and shape of the original
>     pottery
>     >     items?
>     >
>     >     Is there any evidence to suggest that pottery shards were
>     indeed added
>     >     on purpose, in contrast to merely being disposed of an
>     >     non-functional items?
>     >
>     >     Is there any evidence to show that TP WITH pottery shards  works
>     >     better
>     >     than TP WITHOUT shards?
>     >
>     >     Is there any evidence that shards of one range of sizes and
>     >     composition
>     >     and degree of firing give better results in TP than another?
>     >
>     >     Can anyone think of other reasons why pottery shards would be a
>     >     valuable
>     >     addition to TP?
>     >
>     >     Can anyone think of reasons why pottery shards would not
>     make any
>     >     difference?
>     >
>     >     Any facts, comments and observations would be both
>     enlightening and
>     >     appreciated.
>     >
>     >     Best wishes,
>     >
>     >     Kevin
>     >
>