Talk:Terra preta

conflicting claims or information? confusion of terms?
Under Anthropogenic roots the article states; "Because of their elevated charcoal content and the common presence of pottery remains, it is now widely accepted that these soils accreted near living quarters as residues from food preparation, cooking fires, animal and fish bones, broken pottery, etc., accumulated. The intentionality of the formation of terra preta has not been demonstrated, rather it is believed to have formed under kitchen middens. Areas used for growing crops around living areas are referred to as terra mulata. Terra mulata soils are more fertile than surrounding soils but less fertile than terra preta, and were most likely intentionally improved using charcoal."

Under Location the article gives this information; "Plots of terra preta exist in small plots averaging 20 hectares (49 acres), but areas of almost 900 acres (360 ha) have also been reported. They are found among various climatic, geological, and topographical situations.[3] Their distributions either follow main water courses, from East Amazonia to the central basin,[15] or are located on interfluvial sites (mainly of circular or lenticular shape and of a smaller size averaging some 1.4 hectares (3.5 acres), see also distribution map of terra preta sites in Amazon basin.[16]"

So I see there is a term "terra mulata" that perhaps explains some of the confusion but the term "kitchen midden" does not help as these are typically associated with privat dwellings and are usually relativity small. "Numerous small kitchen middens were visible as 2 to 3 foot tall mounds of oyster shell." I understand that this subject isn't well understood but something doesn't sniff right here. — Preceding unsigned comment added by 174.25.0.189 (talk) 20:13, 29 May 2012 (UTC)

There's another problem here: "Terra preta soils are of pre-Columbian nature and were created by humans between 450 BC and AD 950.[6][7] The soil's depth can reach 2 meters (6.6 ft). Thousands of years after its creation it has been reported to regenerate itself at the rate of 1 centimeter (0.39 in) per year[8] by the local farmers and caboclos in Brazil's Amazonian basin, who seek it for use and for sale as valuable compost."

the math doesn't quite seem to add up to "thousands"/ — Preceding unsigned comment added by MEHATCH (talk • contribs) 07:50, 26 November 2012 (UTC)

Save The Human Race
In a Discover article a while ago, it was noted that this may be the way to save the human race, due to that fact that the population of this world is rapidly increasing. If we could convert swaths of the rainforest to agriculture, while taking care of the environment, using organic farming, this may be the way to feed the world. Because it uses charcoal, which stays inert for thousands of years, it could be used for carbon sequestration, which combats global warming.Winkelix 22:02, 13 June 2007 (UTC)


 * You're so right on. 74.195.25.78 (talk) 03:55, 24 January 2008 (UTC)


 * Another way to feed the world is to quit the endless food race and begin NOW to lower our insane numbers.

From the article, the description of terra preta sounds a lot like the indigenous were just plowing in their garbage--back in a society that had no refined products to throw away. Charcoal being the spent wood from the previous nights fire. —Preceding unsigned comment added by Rich Lather (talk • contribs) 01:21, 7 April 2008 (UTC)


 * Actually, there is evidence that the soil was intentionally created. For instance, the charcoal was finely pulverized before being aded to the soil.   However, this article is of poor quality (I would almost argue that it should be rated as start-quality,) and does not do justice to the topic at all, so it is understandable that you might have that misconception.  The article doesn't even discuss the role of symbiotic bacteria in releasing nutrients from the charcoal, or the role of charcoal in retaining nutrients from rainwater.  It also does a poor job of explaining charcoal's role in nutrient retention, or its abiility to reduce need for fertilizers and pesticides.    Works of Sweat (talk) 16:19, 1 May 2008 (UTC)

For those who study it there is no doubt about its being intentional. Please refer to Dr Lehmann's site for example and from there via his outside links to many other hubs of tp study. There's also a very good tp discussion on 'Bioenergy lists' where you can ask all the questions you care for on the tp topic. Here: Terra Preta bioenergy list. Good day. Basicdesign (talk) 06:27, 3 June 2008 (UTC)

--

Regarding "This might have made the benefits of terra preta, such as its self-renewing capacity, less attractive — farmers would not have been able to enjoy the use of renewed soil because they would have been forced to move for safety. Slash-and-burn might have been an adaptation to these conditions."

Need reference for 'self-renewing' -- I think this is a myth -- or grammatical correction in how the sentences are constructed to clarify (if what is meant is that it is possible to 'renew' the soil by adding material and therefore not exhaust its capapcity, which is different that what is implied by "self-renewing") —Preceding unsigned comment added by 200.110.88.3 (talk) 21:21, 29 June 2008 (UTC)

"inappropriate tone"
I wish the person who cared to put that on, also cared about explaining what s/he meant. Hello, are you out there? Please don't just make critics, also make suggestions. Thanks. Basicdesign (talk) 06:27, 3 June 2008 (UTC)


 * I imagine the comment related mainly, or partly, to the thanks expressed to the cited authors for releasing material for inclusion in this page. TONE asks that editors use an impersonal style; this means that the editor's feelings (including those of gratitude to a helpful scholar) should remain invisible in the article. Btw, unpublished research papers should not be cited, as per WP:RS, but papers being in Portuguese is not a problem at all – it is quite natural for sources describing a local phenomenon to be composed mainly in the local language, and this in no way affects their status as reliable sources. See WP:NONENG. Hope that helps. Cheers, Jayen 466 11:43, 22 August 2008 (UTC)

Prounciation Guide Needed
Anyone want to take a stab at a pronunciation key? —Preceding unsigned comment added by 158.35.225.228 (talk) 16:49, 1 October 2008 (UTC)


 * Based on my limited exposure to Brazilian Portuguese, i'd expect something like /ʧeha pɾeta/... anyone with better knowledge? -- Steg.

Before Present
I've been bold and used BC/AD instead, since there aren't many references to historical dates in the article which might make alternative systems appropriate. 118.90.25.170 (talk) 06:03, 27 December 2008 (UTC)

TerraCottem
Not sure whether its worth mentioning: http://www.terracottem.com/pages/en/home.htm it is somewhat similar to terra preta, yet retains moisture better; not sure how its made (DIY?)and whether it is thus appropriate in developing world (remote) locations

If it is; perhaps a new article can be made on it and mentioned in this article in see also section —Preceding unsigned comment added by 91.176.14.197 (talk) 06:55, 8 June 2009 (UTC)

Biochar
Can biochar be used to make terra preta (or terra preta nova ?); eg by mixing it with regular soil; include in article —Preceding unsigned comment added by 91.182.176.136 (talk) 11:58, 21 June 2009 (UTC)

Meaning of O/C and H/C
In the "Wood charcoal" section uses the abbreviations O/C and H/C. Are those Oxygen/Carbon and Hydrogen/Carbon?

Could somebody who knows the meaning of the abbreviations in pedology expand each abbreviation on its first use?

Charletan (talk) 23:32, 5 April 2010 (UTC)

Dark Age Cold Period
It should be pointed out that the listed dates of formation 450 AD to 950 AD covers most of the Dark Age Cold Period. This was a drier time and could well have affected rainfall in the Amazon drying out the mentioned tertiary lakes and ponds. No doubt human effort was made to mix the charcoal, midden heaps and distribute any other composting, but to me the time period of formation leads me to wonder whether this can be reproduced on such a large scale ever again. BradleyHart (talk) 22:27, 19 December 2010 (UTC)
 * That was a period of prosperity for what is now Thailand's Khorat Plateau, but it was followed a few centuries later by the Dark ages of Cambodia, during which the plateau was depopulated for reasons unknown until the 1718 founding of the short-lived Suwannaphum kingdom in the fertile Chi River basin. More to the point, some area farmers have been practicing a limited amount raised-bed farming for garden crops, though I have no knowledge of where they got the idea. --Pawyilee (talk) 15:39, 10 April 2012 (UTC)

Raised-bed farming
University of Utah (2012, April 9). Farmers of 800-years-ago could teach us how to protect the Amazon &mdash; with raised farming beds. Retrieved April 10, 2012, from ScienceDaily. --Pawyilee (talk) 15:20, 10 April 2012 (UTC)
 * PS: I don't have a reference at my fingertips, but a type of raised-bed farming was practiced in the Peruvian desert. This consisted of low-rise stepped pyramids set in moats fed by glacial melt. These were used for about 200 years, until the glaciers melted away in the Medieval Warm Period. The squat pyramids were abandoned and their purpose forgotten until a North American together with a local farmer risked the ire of the neighbors to restore their function. This was some 25 years ago, and even then it was known the glaciers would soon be gone again. Makes me wonder if anything from Wikipedia will survive The Age of Stupid. --Pawyilee (talk) 15:51, 10 April 2012 (UTC)

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"Homemade Terra Preta" Picture
Regarding the picture of homemade terra preta. In North East Utah I could go out into most any field and throw some charcoal onto the mineral soil surface after raking the top layer of organic material away and call it "homemade" terra preta. Whereas in Northern California's "red" soil if I did the same it would be unacceptable, and yet most of the amazon soils should be red in color; with exception to the ones human modified into terra preta. Wouldn't it be better to have an imagine of *actual* terra preta, rather than a homemade version. I'm not aware of many composts that aren't dark in color. Additionally other terra preta images appear to be much darker in surface color, which could be editing of the image. -Zav3nd (talk) 23:56, 8 September 2019 (UTC)


 * Hi. Sure! If you read the article it also suggests that terra preta contains much else than just charcoal. You are welcome to upload good images to Wikicommons so we can use them for articles here on Wikipedia. Regards. RhinoMind (talk) 04:06, 9 September 2019 (UTC)

Anthropogenic?
This study is cited in order to argue that the terra preta might have natural origins. However, it is fairly controversial and several preprints have already been released disputing its results, e.g. here and here. Swaggernagger (talk) 11:24, 28 May 2022 (UTC)

Introductory section contains abuse of Unicode mathematical(?) symbols
Imagine my surprise when I see the characteristic slight jagginess of Unicode mathematical Latin for rendering "terra preta do indío" and "terra preta de indío" in the abovefold. Should I go in and correct this or is this intentional? How long has it been this way (I suppose I should go find the wikiblame thingy)? Ellenor2000 (talk) 01:50, 14 October 2023 (UTC)