Characterization of the soil solution of brazilian Cerrado soils under pasture

Abstract

The aim of the present work was to characterize the soils solution and to examine Al's speciation in soils under pasture in Brazilian Cerrado region. The soils used in this study were collected in the space between the towns of Goiânia, GO and Barra do Garças, MT, to the margins of GO - 060 and BR - 154 highways. For the collection of soil solutions it was used a special equipment built with a PVC tube whose inferior extremity was coupled to a porous tip of special ceramic. To quantify the aluminum ionic species, two methods were used: chemical method of " aluminon " and the method WHAM (geochemical speciation model). The results allowed to conclude that the predominant aluminum ionic species varied in function of soil type, pH and concentration of NO3- in the soil solution. More abundant Al's species in the soils were Al-M.O., Al3+ and Al(OH)4- , in this order.