[Terrapreta] The Science of Terra Preta Formation

[Sean K. Barry]

Hi Jim,

JJ:
I don't know the source of the clay in the pottery shards but I suspect it is the same clay that is in the soil, which would mean that what ever is in the shards is already in the soil. If they made the pottery from clay that was, say, from the mountains, might be a different story.

You remark upon an interesting point.  If forming Terra Preta involved importing nutrients in from other sites, this changes greatly the possibilities of what can be done with a particular site.  Concentrating nutrients form off site and building nutrient holding capacity into the soil is bound I would thing to increase the stock of nutrients and the availability of nutrients for plants on that site.

Clay pottery made from clay on the mountains!?  Maybe this could be found out, the origins and makeup of the pottery shards?  If it shows raw materials from multiple sources, then this could support a hypothesis that the Pre-Columbian people were trying to concentrate nutrients onto a site and with the addition of charcoal trying hold them onto that site.  Already we know they added nutrients in the form of fish bones (obviously not originally from the soil).  They may have realized that the combination of charcoal and nutrients leaves fertility that does not wash away.  A cooking fire in the rain that was left turned out to be a fountain of plant growth later.

Regards,

SKB

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