In this work we try to stand out the main characteristics of the floodplains that occur in the Brazilian State of Amazonas, and its influences on the agricultural activities, based on works developed in that ecosystem. In Amazonas State two great ecosystems arc differentiated: "Terra Firme" (highland) and "Várzeas" (floodplain). "Terra Firme" is a generic term, used to designate local that don't suffer floods provoked by the rivers. The term "Várzea" designate areas at the margins of the rivers of "loamy" or "white" water , subject to periodic floods caused by those rivers. By means of the floods of the "Várzeas" new contributions of sediments are registered, particularly to the margins of the rivers of "white" water as the Solimões river. In the margins of the rivers of clear and black water, there is not "Várzeas" formation. The ones that are formed are by influence of the rivers of "white" water, and they are less fertile. The "Várzeas", due to present soils of higher fertility, are intensively used for agricultural purpose, in the period that are not flooded. The productivity of the crops in the "Várzeas" are higher than that in "Terra Firme" but, in the continuous cultivation, without flood of the rivers, the productivity of crops decay. One of the main factors that limits the continuous use of the "Várzea" areas is the high occurrence of weeds. The distance of the consuming markets is a factor that should be considered, when of the planing of use of the "Várzeas" for agricultural purpose.
Amazon region; Regime of Flooding of "Várzeas"; Soils of "Várzeas"