Elsevier

Geoderma

Volume 110, Issues 1–2, November 2002, Pages 1-17
Geoderma

Pedogenesis and pre-Colombian land use of “Terra Preta Anthrosols” (“Indian black earth”) of Western Amazonia

https://doi.org/10.1016/S0016-7061(02)00141-6Get rights and content

Abstract

The “Terra Preta de Índio” (Indian black earth) or Terra Preta of Western Amazonia is a thick, dark-coloured, anthropic epipedon, usually rich in nutrients. It occurs mostly at the fringes of the Terra Firme, along the Amazon river banks, overlying deep strongly weathered soils. We studied selected chemical, physical and mineralogical properties of seven soils, ranging from the Tertiary Plateau down to the Amazon river floodplain in the Iranduba district, near Manaus, Amazonas, Brazil. Three Terra Preta soils were classified as anthropogenic (Anthropic Xanthic Kandiudult, Anthropic Xanthic Kandiudox and Anthropic Dystropepts). Chemical, mineralogical and micropedological attributes, such as high total and available P and mica flakes in pottery remains found in the Terra Preta, indicate that the origin of soil materials of these anthrosols is closely associated with neighbouring floodplain (várzea) soils and sediments. Amazon floodplain soils were the source of soil material for pottery, since 2:1 clay minerals are not found in the Tertiary Plateau (Terra Firme) sediments. Total and available P contents of Terra Preta are associated with microfragments of bone apatite with high P and Ca values. In the anthrosols under cultivation, these values are less, with increasing Al release suggesting acidification and losses of nutrients. Large amounts of Mn and Zn occur in the anthrosols and in high-fertility floodplain soils. It is unlikely that well-drained Tertiary Plateau (Terra Firme) area far away from lowland Amazon floodplain soils could develop high-fertility Terra Preta on the top of nutrient-poor Oxisols (Latosols). The suggested model of Terra Preta formation between the Tertiary Plateau and nutrient-rich Amazon floodplain does not extend to other nutrient-poor, smaller, floodplains draining the deep-weathered interfluves of the Brazilian Uplands. This raises reservations about estimates of precolonial human population densities for the Amazon basin as a whole, assuming the widespread occurrence of such anthrosols farther inland.

Introduction

The Terra Preta Anthrosols of Amazonia (Indian black earth) are mainly Oxisols, Ultisols and Inceptisols with an anthropic A horizon. They have been described by Katzer (1933), Gourou (1949), Sombroek (1966), Ranzani et al. (1970), Eden et al. (1984) and Andrade (1986), yet many aspects of their origin remain obscure. Detailed studies of these precolonial anthropogenic soils can help answer questions about population distribution, soil carrying capacity, settlement pattern and land uses of ancient Amazonian peoples. According to Roosevelt (1997), the history and ecology of Amazonian habitats are of theoretical and practical relevance to the conservation of the vast tropical rainforest, and yet they are poorly documented. According to radiocarbon dating of Terra Preta sites (Hilbert, 1968), these pre-Colombian societies inhabited the Amazon valley and its main tributaries between 2400±75 and 1525±58 years BP.

Terra Preta Anthrosols in the lower Amazon valley and lower Tapajós have been chemically studied by Kern (1988), Kern and Kampf (1989), Zech et al. (1990), Pabst (1991), Kern and Costa (1997) and Glaser (1999) among others, but little is known about the Terra Preta sites of the middle Amazon valley. Near Manaus, there are many discontinuous patches of well-drained Tertiary Plateau, where Xanthic Oxisols (Latosols) are overlain by black earth deposits pedogenically transformed, containing archaeological artifacts such as pottery fragments, weathered bones and organic remains. The extent of these patches of high fertility epipedons is of local and regional importance, and has been considered as an indication of former sustainable land use (Smith, 1980; Glaser, 1999). Even today, anthrosols are intensively cultivated by local population (the“caboclos”), highlighting its importance to the Amazonian social and ecological landscape (Fig. 1).

The aim of this paper is to relate selected chemical, physical and mineralogical attributes of Terra Preta Anthrosols (TPA) with aspects of precolonial land use and the origin of TPA. Also, TPA attributes were compared with neighbouring nonanthropogenic soils, ranging from the Tertiary Plateau to the floodplain of middle Amazon, emphasizing the pedogeomorphological relationships of their occurrence and implications for precolonial human societies.

Section snippets

Material and methods

We studied seven soils along a toposequence ranging from the Tertiary Plateau (regionally called Terra Firme) down to the Amazon river floodplain (regionally called várzea), in the Iranduba district, near Manaus, Amazonas, Brazil (Fig. 2). The soils were classified in the Brazilian System of Soil Classification (EMBRAPA, 1999) and Soil Taxonomy (USDA, 1999), respectively, as Anthropic Yellow Podzolic (Anthropic Xanthic Kandiudult) (P1), Anthropic Yellow Latosol (Anthropic Xanthic Kandiudox)

Chemical and physical characteristics

The five soils from the Tertiary Plateau and its border (P1 to P5; Fig. 2) are generally dystric in subsurface, and dominated by kaolinite in the clay fraction, similar to those developed from preweathered sediments on the Tertiary Plateau elsewhere in Brazil (Resende et al., 1995) Table 1, Table 2. The two nonanthropogenic soils, P4 and P5, have high levels of Al3+ in the exchange complex. At the surface, the anthropogenic A horizons of P1, P2 and P3 show a distinct eutrophic character, with

Conclusions

The investigated chemical, mineralogical and micropedological attributes, such as high available P and mica flakes in pottery remains of the Terra Preta, indicate that the allochthonous materials in the Terra Preta Anthrosols have their source in the neighbouring floodplain soils and from the Amazon river. Amazon floodplain soils were the only source of soil material for pottery, since 2:1 minerals are not found in upslope Tertiary Plateau soils.

The total and available P contents of

Acknowledgements

The authors are grateful for the careful reviews and comments by Prof. J. Catt and Dr. G. Guggenberger on earlier version of this paper. This work has been partially supported by CAPES-Brazil and CNPq, during Prof. Schaefer's sabbatical in Western Australia.

References (33)

  • B. Glaser et al.

    Black carbon density fractions of anthropogenic soils of the Brazilian Amazon region

    Organic Chemistry

    (2000)
  • A. Andrade

    Investigation arqueologica de los anthrosolos de Araracuara

    (1986)
  • G.W. Brindley et al.

    Crystal Structure of Clay Minerals and Their XRD Identification

    (1980)
  • De Carvajal, G., 1894, (1542). Descubrimiento del Rio de Orellana. Descubrimiento del Rio de Las Amazonas, compiled by...
  • W.M. Denevan

    A bluff model of riverine settlement in prehistoric Amazonia

    Annals of the American Geographers

    (1996)
  • P. Duchaufour

    Handbook of Pedology—Soils, Vegetation and Environment

    (1998)
  • M.J. Eden et al.

    “Terra Preta” soils and their archaeological context in the Caqueta Basin of southeast Colombia

    American Antiquity

    (1984)
  • Manual de métodos de análise de solo

    (1997)
  • Sistema Brasileiro de Classificação de Solos

    (1999)
  • E.A. FitzPatrick

    Soil Microscopy and Micromorphology

    (1993)
  • P. Gourou

    Observações geográficas na Amazônia

    Revista Brasileira de Geografia

    (1949)
  • G. Guggenberger et al.

    Land-use effects on the composition of organic matter in particle-size separates of soils: II. CPMAS and solution 13C NMR analysis

    European Journal of Soil Science

    (1995)
  • P.P. Hilbert

    Archäologische Untersuchungen am Mittleren Amazonas. Marburger Studien zur Völkerkunde 1

    (1968)
  • F. Katzer

    Geologia do Estado do Pará. Boletim do Museu Paraense Emilio Goeldi de Historia Natural e Etnografia

    (1933)
  • Kern, D.C., 1988. Caracterização pedológica de solos com Terra Preta Arqueológica na região de Oriximiná, Pará. Porto...
  • D.C. Kern et al.

    Composição quı́mica de solos antropogênicos desenvolvidos em Latossolo Amarelo derivados de lateritos

    Geociências

    (1997)
  • Cited by (184)

    View all citing articles on Scopus
    View full text