Kayapo Soil Management: Urban and Rural Practices for the Creation of Amazonian Dark Earths

Transcription

1 Kayapo Soil Management: Urban and Rural Practices for the Creation of Amazonian Dark Earths

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6 Large areas of Anthropogenic Landscapes Four large classes of human activities that have shaped Amazonian landscapes: Large-scale earthworks Fluvial management and floodplain soil manipulation Manipulation of vegetation through domestication, semi - domestication, varietal selections, propagation of wild plants through direct planting, or creation of conditions for propagating them, management of successional processes, etc. Fire. These include large-scale, landscape-level conflagrations like some of the burning of the cerrado and seasonally dry forests; fires associated with shifting cultivation landscapes, and most of the current forest clearing.. Absent from most of these recent discussions of the use of fire in landscapes are its uses as a highly targeted indigenous land management technique, such as that of in-field burning from the Kayapó.

7 Urban Kayapo Settlement Structure 1. Central plaza is surrounded by houses 2. Houses with door yard gardens and cooking areas: (Ki krê bum) are filled with fruit trees, medicinal plants, seedlings, botanical experiments, and various residues of daily lives. These also contain garbage disposal middens compost, or toss middens and burning middens which can also be 3. Hearths (kôt). 4. Outer area, the atykma,. Atykmas may also be burned periodically as debris builds up, or as a means of reducing the attractiveness to dogs and vermin of the organic residue from hunting and food processing. The term atykma owes its etiology to tyk which means black or dark.

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9 After Clark Erickson 2004

10 Dynamics of Terra Preta? Table 1: Mean soil values (0-10 cm) in an urban catena. ph C [gm N [gm P [mg Ca Mg [cmolc K [mg [cmolc Plaza Garden Midden* Midden** Atykma *Bury/toss midden; **Burn midden

11 Terra Mulata: The Question of Fire Indigenous populations used fires to manage vegetation throughout their occupation of the New World. Fire has thus been demonized as a land management tool even though evidence from virtually all forested landscapes has revealed its utility and ecological importance). Kayapó, : low-biomass, cool fires, limited in scale, set throughout the year for Wildland management. Kayapó agriculture embraces various practices in many different types of ecosystems. The landscapes in which the Kayapó regularly move must be understood as a canvas on which a range of techniques from highly intensive to subtle manipulations are used. Planting occurs within virtually all the various savanna and forest types vegetation management, including weed control. reduce biomass in grasslands and forest understories, to more completely burn slash, to create fire breaks, reduce fire laddering by slash and vines. These reduce the overall flammability of the vegetation. Low intensity fires are cool enough to walk through, and tend to enhance, rather than cross, forest/grassland boundaries..kayapó Agriculture: The World of the Cool Fire: Fire is used in virtually all Kayapó production systems. To live among the Kayapó is to live in a place where parts of the landscape smolder. The soft or cool fires are more controllable, and they create incompletely burned residues charcoal of varying sizes. These types of combustion products appear to be one of the key elements in the soil stability of the ADEs.

12 Types of burning and additions preburn planting, structuring the agricultural field in the felling phase for its concentric zones, coivara burning (burning of residual slash ), infield burning, scattering of cooking residues, burning crop residues, ash additions, mulching, planting mix additions, ant and termite nests additions, and palm mulches and ashes

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16 Ash Nutrients Table 2: Composition of Available Nutrient Additions From Ash Source ph C [g N [g P [mg Ca [mmol c Mg [mmol c K [mg Yam ash/coivara mix ,891 Yam mix ,633 Yam ash ,739 Banana ash ,294 Rice ash ,646 Inaja ash ,229 Sweet potato ash ,060 Beans ash ,349 In-field Middens ,531 Yam planting mix Ant nests Ant nest (1) Ant nest ash (2) ,842 Ant nest ash (3) ,848 Ant nest ash plus litter ,851

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19 In Field Burning Table 3: Impacts of in-field burning 4-year-old Manioc field on soil nutrients and carbon. p H C [g N [g P [mg Ca Mg [cmol c [cmol c K [mg Manioc (unburned) Manioc (in-field burn) Manioc Replant unburned 2 2 Manioc Replant (infield burn)

20 Intensive and non intensive managements Table 4: Soil characteristics in managed and unmanaged two-year-old agricultural plots. ph C [g N [g kg - 1 ] P [mg Ca [cmol c Mg [cmol c K [mg kg - 1 ] Unmanaged Managed Highly Managed For methods see Table 1.

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