Impact of an agricultural chronosequence in recharge areas of aquifers in the Brazilian savannah

Abstract

Current study was conducted, in 2010, on the Boa Vista Farm at the Rio Claro watershed of the southwestern region of Goiás, state, Brazil. The region features micro-reliefs with marshy fields and predominantly Haplic Plinthosols. Most areas were incorporated into the agricultural production systems without evaluating the impact on their hydro-physical characteristics. Current analysis evaluates the transformation impact of marshy lands into agricultural areas through an investigation of empirical methods of water infiltration into the soil. Three chronosequenced areas for agricultural use and a preservation area were selected. Water infiltration in the soil was analyzed by field data and by calculations following Kostiakov, Horton and Lewis-Kostiakov. Models overestimated infiltration rates at the beginning of the process and compared to those from field data. The model proposed by Horton was highly similar to rate of basic infiltration speed harvested from field data. Structural quality was reduced through infiltration velocity in the area with human interference with grown under no-tillage system.