**2. Dark earth as anthropogenic soil: the legacy of Curt Nimuendajú**

Foreign researchers and travelers first learned about the existence of this uniquely fertile soil by local informants. Herbert Smith [11], for example, had this description to give after his visit to Santarém, "…the rich terra preta, 'black land', the best on the Amazon (…) is a fine, black loam, a foot, and often two feet thick. Strewn over it everywhere we find fragments of indian pottery, so abundant in some places that they almost cover the ground." Friederich Katzer [12], a German geologist, gave the "*Schwarze Erde*" (black earths) a natural origin and interpreted them, as they were located near the rivers, as ancient lake deposits (*igapó).* He analyzed three soil samples from *Terra Preta* and was surprised by their exceptionally high content of organic matter. He noticed a great quantity of potsherds as well of indigenous origin and concluded from this observation that these "ancient lake deposits" were once cultivated by the ancient Amazonians, when the region was much more densely populated.

Curt Unkel (1883–1945) went beyond the mere confirmation of the existence of the Amazonian dark earths and the understanding that these were places in which archeological objects could be found. Beyond a doubt, Unkel (later receiving his Indian-sanctioned moniker "Nimuendajú") is one of the most important 20th century researchers of Amerindian cultures and has done invaluable work for the investigation and protection of Brazilian indigenous populations [13].

In his research on *Terra Preta*, Nimuendajú started from the widely-understood fact, that wherever a certain earth was found (locally called *Terra Preta de Índio*), ceramic fragments of earlier indigenous cultures were always present. Following this premise, near the city of Santarém, at the confluence of the Rio Tapajos and the Amazon, Nimuendajú registered the location of 63 previously unknown *Terra Preta* sites (**Figure 1**) [14].

In 1945, in a letter to the ethnologist Herbert Baldus, Nimuendajú outlined his ideas about the origin of the *Terra Preta*. This letter, summarizing the considerations of many earlier studies, was a watershed publication in *Terra Preta* knowledge and major hallmark of Nimuendajú's personal research legacy, as it contains nearly all the keys ideas of all subsequent *Terra Preta* research [15].

His systematic analysis of the locations of the *Terra Preta* led him to reject the previously prevailing opinion that the special soil was of a natural origin and the result of flooding, the remnants of lake sediments or even volcanic ash [16]. Nimuendajú concluded, by comparing the spatial distribution of the *Terra Preta* that the soils were totally anthropogenic, did not occur naturally and clearly

**131**

**Figure 1.**

*Klaus Hilbert).*

*From the "*Terra Preta de Indio*" to the "Terra Preta do Gringo": A History of Knowledge…*

an outcome of indigenous production. Nimuendajú did not, however, mention whether he assumed this soil was created intentionally or unintentionally. What he did say with certainty and much authority was that all *Terra Preta* in Amazonia was of indigenous origin. Their formation, he explained, was due to the burning of wood in hearths and not the product of slash-and-burn techniques. He concluded that all dark earth sites were necessarily archeological sites, because of their clear association with Amazonian peoples. He was thereby squarely positioning himself in opposition to the prevailing interpretation that presumed a natural production

*Map of* Terra Preta *sites located in the Rio Tapajós area, drawn by Curt Nimuendajú in 1937 (property:* 

Nimuendajú bequeathed, so to speak, *Terra Preta*, as a serious research topic to the archeological community. Nevertheless, the academic community was slow to

Betty Meggers and Clifford Evans [17], who eventually picked up where Nimuendajú research had left off, initially began their research inquiries following the work of Charles Hartt [18] and Orville Derby [19] by conducting their research on Marajó Island. They were more interested in the artificial mounds of the Marajoara culture, located on the eastern part of the island, than in *Terra Preta*. Initially, the researcher to most fully grasp the gravity of Nimuendajú's conclusions regarding *Terra Preta* was Franciscan priest Protásio (Günther) Frikel. He, in turn, bestowed upon fellow researcher Peter Paul Hilbert [20] the location of more than 40 *Terra Preta* archeological sites found in the vicinity of the Nhamundá and Trombetas rivers, where Frikel happened to hold a parish seat. Both Hilbert and Frikel associated the potsherds found in and about these sites, again following Nimuendajú's groundwork, with the Konduri natives, mentioned in the earliest European chronicles. It is likely that this was the time and place when truly system-

*DOI: http://dx.doi.org/10.5772/intechopen.93354*

process at work in *Terra Preta* genesis.

**3.** *Terra Preta* **as an archeological site**

ascertain the value of his contributions.

atic archeological research on *Terra Preta* first began.

*From the "*Terra Preta de Indio*" to the "Terra Preta do Gringo": A History of Knowledge… DOI: http://dx.doi.org/10.5772/intechopen.93354*

#### **Figure 1.**

*Ecosystem and Biodiversity of Amazonia*

introduction of artificial fertilizer. These primary forest soils have a low pH value, which means they are extremely alkaline and suited for long-term agricultural use. The usual agricultural workaround, known as slash-and-burn, produces ash and coal, which provide for a temporary fertility. Immediately thereafter, the areas are generally abandoned as the soil fecundity declines and much waste in biomass and

The indigenous knowledge of *Terra Preta*, their location and qualities are still invaluable to the current discussion (for a more in-depth discussion on the subject see Manuela Carneiro da Cunha [9]). Simply taking into consideration solely peerreviewed scientific journal publications is, in our opinion, insufficient [4]. Such a limited approach creates a distorted perspective. Such a selective corpus might inspire the conclusion that only Western-based scientists and 21st century business concerns discovered and developed the fundamental benefits of the *Terra Preta de Índio.* Such a clearly simplified historically misinformed view might even be used for legitimizing claims to the economic exploitation of this important indigenous knowledge [10].

**2. Dark earth as anthropogenic soil: the legacy of Curt Nimuendajú**

fertile soil by local informants. Herbert Smith [11], for example, had this description to give after his visit to Santarém, "…the rich terra preta, 'black land', the best on the Amazon (…) is a fine, black loam, a foot, and often two feet thick. Strewn over it everywhere we find fragments of indian pottery, so abundant in some places that they almost cover the ground." Friederich Katzer [12], a German geologist, gave the "*Schwarze Erde*" (black earths) a natural origin and interpreted them, as they were located near the rivers, as ancient lake deposits (*igapó).* He analyzed three soil samples from *Terra Preta* and was surprised by their exceptionally high content of organic matter. He noticed a great quantity of potsherds as well of indigenous origin and concluded from this observation that these "ancient lake deposits" were once cultivated by the ancient Amazonians, when the region was much more densely populated. Curt Unkel (1883–1945) went beyond the mere confirmation of the existence of the Amazonian dark earths and the understanding that these were places in which archeological objects could be found. Beyond a doubt, Unkel (later receiving his Indian-sanctioned moniker "Nimuendajú") is one of the most important 20th century researchers of Amerindian cultures and has done invaluable work for the

investigation and protection of Brazilian indigenous populations [13].

nearly all the keys ideas of all subsequent *Terra Preta* research [15].

In his research on *Terra Preta*, Nimuendajú started from the widely-understood fact, that wherever a certain earth was found (locally called *Terra Preta de Índio*), ceramic fragments of earlier indigenous cultures were always present. Following this premise, near the city of Santarém, at the confluence of the Rio Tapajos and the Amazon, Nimuendajú registered the location of 63 previously unknown *Terra Preta*

In 1945, in a letter to the ethnologist Herbert Baldus, Nimuendajú outlined his ideas about the origin of the *Terra Preta*. This letter, summarizing the considerations of many earlier studies, was a watershed publication in *Terra Preta* knowledge and major hallmark of Nimuendajú's personal research legacy, as it contains

His systematic analysis of the locations of the *Terra Preta* led him to reject the previously prevailing opinion that the special soil was of a natural origin and the result of flooding, the remnants of lake sediments or even volcanic ash [16]. Nimuendajú concluded, by comparing the spatial distribution of the *Terra Preta* that the soils were totally anthropogenic, did not occur naturally and clearly

Foreign researchers and travelers first learned about the existence of this uniquely

land use is the overall result in this highly inefficient approach [8].

**130**

sites (**Figure 1**) [14].

*Map of* Terra Preta *sites located in the Rio Tapajós area, drawn by Curt Nimuendajú in 1937 (property: Klaus Hilbert).*

an outcome of indigenous production. Nimuendajú did not, however, mention whether he assumed this soil was created intentionally or unintentionally. What he did say with certainty and much authority was that all *Terra Preta* in Amazonia was of indigenous origin. Their formation, he explained, was due to the burning of wood in hearths and not the product of slash-and-burn techniques. He concluded that all dark earth sites were necessarily archeological sites, because of their clear association with Amazonian peoples. He was thereby squarely positioning himself in opposition to the prevailing interpretation that presumed a natural production process at work in *Terra Preta* genesis.

#### **3.** *Terra Preta* **as an archeological site**

Nimuendajú bequeathed, so to speak, *Terra Preta*, as a serious research topic to the archeological community. Nevertheless, the academic community was slow to ascertain the value of his contributions.

Betty Meggers and Clifford Evans [17], who eventually picked up where Nimuendajú research had left off, initially began their research inquiries following the work of Charles Hartt [18] and Orville Derby [19] by conducting their research on Marajó Island. They were more interested in the artificial mounds of the Marajoara culture, located on the eastern part of the island, than in *Terra Preta*.

Initially, the researcher to most fully grasp the gravity of Nimuendajú's conclusions regarding *Terra Preta* was Franciscan priest Protásio (Günther) Frikel. He, in turn, bestowed upon fellow researcher Peter Paul Hilbert [20] the location of more than 40 *Terra Preta* archeological sites found in the vicinity of the Nhamundá and Trombetas rivers, where Frikel happened to hold a parish seat. Both Hilbert and Frikel associated the potsherds found in and about these sites, again following Nimuendajú's groundwork, with the Konduri natives, mentioned in the earliest European chronicles. It is likely that this was the time and place when truly systematic archeological research on *Terra Preta* first began.

During the subsequent 10 years, Peter Paul Hilbert located, sample and excavated *Terra Preta* sites along the middle Amazon River [21]. Later, archeologists associated with the Museu Paranse Emilío Goeldi in Belém, such as Mario Simões, continued Hilbert's work and even intensified the systematic approach towards treating *Terra Preta* soils as bonafide archeological sites.

Under Betty Meggers' intellectual supervision and financial support, Mário Simões and his assistants, located and pit-tested hundreds of *Terra Preta* sites, mostly along the Amazonian tributary rivers, such as Rio Negro, Rio Madeira and Rio Tocantins [22]. Recognizing these *Terra Preta* sites mainly as deposits of discarded refuse (kitchen middens), these archeologists were largely interested in the material cultural remains, such as fragmented ceramic vessels and some rare polished stone implements "thrown away" by their original, ancient owners.

Quantifying and classifying the ceramic fragments by their diagnostic features, such as decoration, style, technique and form of vessel, this group of researchers created a chronology-based model of site categorization and orientation. According to the dominant typological pattern of the ceramic fragments, four cultural traditions were pronounced: Zone-Hachured, Incised Rim, Polychrome and Incised-Punctuated [23].

As most of these habitation sites had a multi-compositional sequence of archeological remains, it was concluded that the ancient Amazonians had a semi-nomadic strategy of survival. This was necessitated, it was argued, by the poor soil conditions [24] which could not support extended agricultural use and therefore, neither a complex society nor a high population rate. Despite the extraordinarily high biodiversity of the Amazon region, it was claimed, the habitants had to change their settled areas periodically, which on one hand, explained the great number of *Terra Preta* sites and, on the other, their frequent reoccupation by varying archeologically displayed cultures. Betty Meggers elaborates on this paradoxical situation contrasting the Amazonian environment and archeological record with the idea of a "counterfeit paradise" [25].

Donald Lathrop [26], José Brochado [27] and Anna Roosevelt [28] questioned this model of environmental restraint and soil poverty, and its inherent relationship to a low level of social complexity. They defended the opposite scenario of a rich and fertile Amazonian environment, which supported a large population and complex societies, based on powerful and interrelated chiefdoms.

Eduardo Neves, observing a gradually waning academic interest in these debates and marked shift away from topics involving ancient Amazonia as important research terrain, felt impelled to develop an interdisciplinary-driven and internationally-inclusive research strategy. Initially located in the lower Rio Negro and Rio Solimões region, he united a group of scientists from soil sciences, anthropology, biology, ecology, geography, geology and sociology and set out to reinvigorate the research topic of *Terra Preta*. This wave of researchers made pivotal contributions to the knowledge of Amazonian Archeology, focusing most recently on the question of the origins of early crop domestication [29–35].

Contemporaneously, Michael Heckenberger [36], Denise Schaan [37, 38] and Denise Gomes [39] reignited discussion on the social-power relations expressed by the construction of the monumental structures of the ancient Amazonians. Their primary focus being the massive vertical constructions and their reflection of a high social and cultural complexity. Some examples include the mound builders of Marajó Island, the road builders of the Tapajos, in *Alter do Chão*, near Santarém, the village builders of the upper Rio Xingu or the geoglyph builder in Rondônia and Acre.

Despite all of these advances in the knowledge of *Terra Preta*, the subject was generally, yet again, abandoned as a serious research focus and the idea of the "dark earth" as a socio-cultural phenomenon, a massive public works project of horizontal monumentality, or as an expression of high social organization and cultural complexity, was again, relegated to the academic shadows.

**133**

*From the "*Terra Preta de Indio*" to the "Terra Preta do Gringo": A History of Knowledge…*

While archeologists, and to some extent anthropologists, were becoming more deeply involved in the discussions about the relatively high or low fertility of the Amazon region, investigations into the soil's relation to social complexity, sedentary or semi-nomadic lifestyles or population density remained secondary at best. Other scientists took up the subject of *Terra Preta* and ran with it. Soil scientists more and more gained international public interest and headlines from prestigious and highly

In the early 1980s, research on the "natural scientific character" of the *Terras Pretas* began in earnest, with the investigations of Eije Erich Pabst and Gerhard Bechtold. They demonstrated, for the first time, that the "black earth" differed dramatically in chemical composition from the typical, reddish oxisols of Amazonia. They re-confirmed the soil's higher pH value, abundance of organic substances, and

How the *Terra Preta de Índio* could have come about what the leading question of Eije Erich Pabst, who not only explored the soil properties, but also ethno-pedological aspects. Pabst posited that if one could determine how the *Terra Preta* was arose from the oxisol, then one could recreate such improved soil enhancements today. As part of his strategy, Pabst visited several ethnic groups in the Amazon region. Here he found quite diverging opinions expressed, including their natural provenance by the Assurini, divine origin, as expressed by an Arawete: "the forest God threw them down from heaven," and an anthropogenic or "man-made" origin. Finally, some Waiapi natives simply explained that they just did not know how the soil came

Despite efforts, Pabst was not able to track down a definitive indigenous "recipe" for the manufacture of *Terra Preta* during his oral interview investigations. Pabst emphasizes, however, that this knowledge once existed, but was lost in the course of the population collapse the Amazonian people suffered during and since the European colonization. The indigenous populations were largely displaced from any favorable localities and generally forced into non-sedentary modes of survival. It is stressed that this historic and unmerited loss of cultural expertise should in no way be equated with native inventive capacity, agricultural competence or claims

Whether Amazonian black earths were intentionally produced or not, continues

Ethnopedological research has shown that there still do indeed exist Amerindian

Moreover, historical studies have shown in other important cases that the ahistorical perspective, that the indigenous products are results of pure happenstance, stems from the faulty view of native peoples as "children of nature"—a perspective

to fuel debate. On the one hand are the positions that exclude all intentionality and assume that the *Terra Preta* resulted to the indigenous lifestyle. This was more or less the opinion of the earliest archeologists and anthropologists conducting research in the twentieth century. On the other hand, positions exist that presume a very clever technique for the deliberate production of humus, even going so far as to

groups whose lifestyle leads directly to the production of *Terra Preta* [41]. Even without this evidence, it would seem plausible to presume that at least some of the groups formerly living in the Amazon had consciously carried out soil improvement measures by adding a combination of plant charcoal, ceramics and organic matter [42]. Considering the many innovations of the Amazon Indians [43], it is highly unlikely that such a vital adaptive measure and its life-improving results would have totally escaped the conscious awareness of the indigenous population living in

suggest specific ceramics were created and then used in the process [40].

Amazonia prior to the arrival of the Europeans.

**4. The scientific characterization of** *Terra Preta de Índio*

*DOI: http://dx.doi.org/10.5772/intechopen.93354*

much higher nitrogen and phosphorus levels [2, 3].

visible publications.

to be [3].

thereof.

*From the "*Terra Preta de Indio*" to the "Terra Preta do Gringo": A History of Knowledge… DOI: http://dx.doi.org/10.5772/intechopen.93354*
