Science Forums 2

[gost]

LOL about the alpaca poop, Michael. I like the stuff not only because it seems appropriate to making Amazonian soil, but because it's high in N and you can use it directly on plants without it burning, much like rabbit manure. Not only that, but I have a neighbor who raises alpacas and is happy to get rid of the waste. I add it into my compost pile and figure the extra microbes can only help the process.

As far as where I live, I'm in the upper right hand corner of the US, about 75 miles north of Seattle, Washington, in a rural area just below the Canadian border. My wife and I own six acres of land in the hills where we play at organic gardening, amongst other things.

Those are some good links you've come up with, Michael, as always. I've run across the Eprida site before and find it pretty interesting. I don't know quite what to make of the charcoal temperature business and how to apply it here, but here is a quote from the author of that presentation, Danny Day, in another article, specifically about Terra Preta:

" The initial phase of the meetings started with a review of the current
knowledge of man made soils called terra preta occupying an area of
the Amazon that total to twice the size of Britain. Carbon was added
to these soils in the form of a low temperature charcoal. Using low
intensity smoldering fires created these charcoals. By analysis, we
can tell that they were created 1000-2000 years ago and were part of a
soil management practice designed to take a yellow clay soil of
limited biological productivity and convert it into some of the
richest soil in the world. A thousand years after its creation it is
so well known in Brazil, that it is dug up and sold as potting soil. . .

". . . Low temperature woody charcoal (not grass or high cellulose) has an interior layer of bio-oil condensates that microbes consume and is
equal to glucose in its effect on microbial growth (Christoph Steiner,
EACU 2004). High temp char loses this layer and does not promote soil
fertility very well."

The implication is that the charcoal was produced at low temps, but he doesn't state the exact temperature range. None the less, it seems probable that because the ADE soils have a fair amount of "brown" (incompletely charred) charcoal present, it can be inferred that the temps must have been in the lowest ranges of charcoal conversion.

The temperatures that I'm using are much lower that the Eprida temps you posted above. I'm trying to stay within the range of 470-500F (240-260C), with the idea that preserving the bio-resins and oils is extremely important in the regulation of N, as indicated in the literature.

I got a kick out of the idea of discussing Terra Preta with the boys at the pub. Last weekend, while I was making charcoal, my neighbor Auggie, a retired logger who we buy eggs from, stopped by.

"Howdy neighbor," he said. "Watcha doin'? Fixin' to smoke some fish?"

"Naw," I said. "I'm trying to make some charcoal."

"Oh." Long pause. "How come? You gonna have a barbecue?"

"No, I need a special kind of charcoal to make something called Terra Preta."

"Oh." Another long pause. "That some kind of Mexican dish?"

"No, It's a type of soil that the people in the Amazon used to make to grow their food in."

"So . . . you're makin' dirt?"

"Yep."

"How come? Don't you have enough already?"

"Well, yeah, but you know, making Terra Preta just might be a way to help solve the problem of global warming. I'm just playing around with the idea."

"So . . . you're makin' charcoal, to make some dirt so you can fix global warming?"

"Yeah, something like that?"

"Well, ain't that something!" Long pause. "Say, you got any more of that home-made raspberry wine in the fridge?"

"Sure Auggie, help yourself."

Around here, everyone's used to my crazy notions. I'm known as the mad scientist/songwriter/farmer/computer geek with the loud electric guitar and the finest raspberry wine ever made. I owe it all to alpaca poop, I tell them.