Saturday, 15 July 2006

Formation of Dark Earth Soils in Western Amazonia, Iquitos, Peru.

Andrew Zimmerman and Augusto Oyuela-Caycedo. Univ of Florida, 241 Williamson Hall, Gainesville, FL 32611

Dark Earth soils, in contrast with other tropical soils, are characterized by high nutrient concentrations (N, P, Ca, and K), high organic matter contents and the presence of archaeological artifacts. Dark Earth soils and associated archeological sites are widely distributed throughout Amazonia, the majority of documented sites occurring in Brazil. This paper presents data for an archeological site and associated potential Dark Earth soil located Southwest of Iquitos, Peru on a terrace above the western Amazon floodplain. The sandy matrix of this soil contains artifacts and charcoal that support an origin related to human occupation; despite lower base saturation (115-250 mg/kg Mg & Ca) and carbon concentrations (< 1.4 %) indicated by preliminary geochemical data. AMS radiocarbon dates place human occupation and soil formation between ~2500-1430 BP. Analyses of surface area and morphology of sediments and charcoal will be presented. Chemical and physical characterization of these soils will be combined with climatic data to explore the mechanism of formation and relationship between formation and global climate.

Back to 1.6B Amazonian Dark Earth Soils (Terra Preta and Terra Preta Nova): A Tribute to Wim Sombroek - Poster
Back to WCSS

Back to The 18th World Congress of Soil Science (July 9-15, 2006)