The writer is a semi-retired energy economist with considerable agriculture in his background and a lot of bioenergy experience. He has never been to Amazonia but can read scientific Portuguese. He has lived and work in Paraguay and traveled to neighboring parts of Brazil. Home base is Carolina, Puerto Rico.

His understanding of "terra preta" is that it is a multi-component soil-management system which includes biomass charcoal, compost and other ingredients including possibly an acid such as urine and/or chards. Do to the haphazard organization of research, we still do not have a clear idea of how the ancients made their charcoal or an adequate understanding of the management systems, which must have varied from place to place, as abandoned sites are found scattered over an area the size of France.

The primary function of the porous charcoal appears to be to provide storage for minerals and a habitat for the microbiota which facilitate the storage and ingestion of minerals by plants. When observed by an electron microscope, the charcoal turns out to have an elaborate interior structure with more internal surface area than external !

The function of the chards, in those cases where their placement is orderly, may be to increase the surface area on which microbiota can "sit" while they do their work of bonding or "snipping" molecules.

The need which microbiota have to attach themselves to something while they "go about their business" has been well established in diverse locations. For exampe, the studies of OTEC heat exchangers carried out off Punta Tuna, Puerto Rico, in the 1980's. The successful "honey comb" anaerobic digester at the Barcardí distillary at Cataño, Puerto Rico, over a decade ago. The distillary obtains all its steam from the burning of biogas obtained by the digestion of distilling-tower "slops", which were formerly dumped in the ocean !

I understand [although some "authorities" deny this] that abandoned sites near Manaus, Brazil, have been "mined" for many years and the resulting "terra preta" sold to commercial farmer in the metropolitan area.

Some extroardinary increses in yield have been obtained both in academic research and commercial operations by the application of "terra preta". We know it can work, but we really don't know how or how to replicate it on a large scale.

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My understanding is that human urine is sterile when it comes out of the pipe, but it is safest to compost human solid waste at a high temperature and leave it for a year before using it.

Are you using right as it plops?

The shipping and packing supplies you are not able to recycle are nothing more than a carbon source for your use. At the very least you should be able to cut or shred if possible any of this material and put in the compost. It can also be made into a fuel for your wood stove. There has to be many other ways of using this resource you have, like using it as a building material. Look up "Papercrete", like this site http://www.papercrete.com/cheap.html, there are others. So much information - So little time.

I don't know what changed but I was having issues loading your site (to the point I couldn't even comment to tell you) since December but Magically today it just popped up with no issues. I have been missing out on your pictures, I am so glad to have it back.

Have you thought about using some of that cardboard or anything else you have in the barn that could trap air movement as insulation for the walls and ceiling of your shed? Anything that will slow or block the transfer of air can help.

I don't know what happened, but I'm glad you're back!

That's another great idea for cardboard! We're definitely going to insulate the shed --- had planned to just buy fiberglass insulation, but maybe cardboard would work in spots. I wonder what its R value is?

Corrugated cardboard should work pretty well as an insulator, I think. People are building complete houses out of it.

The problem is that you have to keep it dry, otherwise your insulation would be rotting away between your walls. You'd get more mushrooms than you bargained for.

The outside walls are covered with HDPE.

In my opinion, this house is more like a proof of concept than a real house. And it was designed in Australia; not a continent famous for its rains!

I agree that in a climate like in my neck of the woods such a "house" wouldn't last. Cardboard soaks up water and then looses its strength. Keeping it dry would just be too difficult in a temparate climate.

The Japanese pavillion at the expo 2000 had a load-bearing skeleton made from wound recycled paper tubes.

Terra preta seems like an awesome way to naturally process or transform your organic waste as well as your cardboard.

If you are still finding that you have an abundance of cardboard after putting in your vermiculture bin & your terra preta mound, you could try using the extra cardboard to kill weeds when starting up new no-till garden beds. You can even use the terra preta that you've made to go on top of the weed-killing cardboard to use for your planting.

Here is a link that includes steps to making a Permaculture garden with the use of cardboard:

http://permaculturenews.org/2013/07/08/an-easy-way-to-start-a-new-permaculturegarden/