Reconstruction of ancient use of Terra Preta using molecular markers and compound-specific stable isotope ratios (d13C)

DFG GL 327/5-1,2

From 01/2006 to 12/2008

Principal Investigator: Bruno Glaser
Staff: Jago Birk, Alexander Hänel

In Amazonia, nutrient-poor Oxisols and Ultisols predominate which are hardly usable in a sustainable way. However, within this landscape, a mosaic of highly fertile soils occur, known as Terra Preta (do Indio), which are the product of sustainable land management of pre-Columbian Indians. Our previous examinations showed that the high and stable soil organic matter stocks of these soils were decisively attributed to pyrogenen carbon. However, input of nutrient-poor charred residues does not explain the high nutrient contents (particular N, P, about, Mg) of Terra Preta soils. Thus, the goal of the present research project is it therefore, to gain insight into pre-Columbian land-use through small-scale analysis of different phosphorus forms, stable biomarkers and their stable isotope ratios. Especially, one should distinguish between the entry of human and animal excrements as well as between aquatic and terrestrial biomass. From the results of this research, we expect information on the enrichment of Terra Preta with nutrients as well as the heterogeneity of the entry-paths.