Amazonian dark earths in the fertile floodplains of the Amazon River, Brazil: an example of non-intentional formation of anthropic soils in the Central Amazon region oleh Rodrigo Santana Macedo, Wenceslau Geraldes Teixeira, Hedinaldo Narciso Lima, Adriana Costa Gil de Souza, Francisco Weliton Rocha Silva, Omar Cubas Encinas, Eduardo Góes Neves