The Semiarid Region of Northeast Brazil covers around 750,000 km² and the Pre-Cambrian areas are dominated by shallow and poorly developed soils. According to the Brazilian System of Soil Classification the soils of the region are predominantly classified as Lithic Neosols, Luvisols and Planosols. This study aimed to characterize and classify 12 soil profiles in four toposequences representative of the common occurrence of Luvisolics in the Semiarid Region of Northeast Brazil by the Brazilian System of Soil Classification. Two sequences were selected with soils developed from gneisses, in the region of "Cariris Velhos", Paraíba State, and two others, in the "Sertão" region of Pernambuco State, with soils developed on micaschists and phyllite. The soils were morphologically characterized and samples collected for physical and chemical analysis. The changes in the identification criteria of the chromic character introduced in the second version of the Brazilian System of Soil Classification seem to have achieved the objective, allowing the classification of the 10 studied soil profiles of Non-Calcic Brown Soils as Chromic Luvisols. All studied Luvisols were adequately classified by the Brazilian System of Soil Classification up to the fourth level, except for the Luvisol with sodic character, which is not considered as subgroup in the current system version. This study suggests the inclusion of a sodic subgroup in the class of Orthic Chromic Luvisols (Luvissolos Crômicos Órticos) to account for these soils, which differ from typical soils because they have a sodic character from the surface down to a depth of 100 cm.
soils of "Sertão"; soil classification; gneisses; micaschists; phyllite
