Abstract

LEMOS, Vanda P. et al. Nutrients in Amazonian Black Earth from Caxiuanã Region. J. Braz. Chem. Soc. [online]. 2011, vol.22, n.4, pp. 772-779. ISSN 0103-5053.  http://dx.doi.org/10.1590/S0103-50532011000400022.

Dispersion of nutrients in Amazonian black earth (ABE) can provide information on human activities of the inhabitants of the Amazon region. Studies on the pH, available phosphorus (P), organic matter (OM) and the exchangeable cations Ca^{2 +} and Mg^{2 +} were performed on soil samples from horizons A₁ and A₂ over an area with TPA (north-south and east-west) at a site called Ilha de Terra, located in the Conservation Unit Caxiuanã National Forest, Melgaço County, Brazil. The results indicated that the OM and Ca²⁺ are the ones with greater dispersion. Higher correlations were found between OM-Ca-Mg to near the central area. This leads to the inference that the dispersion geochemistry of MO, Ca, Mg and P in archaeological sites with TPA is related to past human activities.

Keywords : nutrients; Caxiuanã; soils; Amazonian black earth.