PEDOGENETIC PROCESSES AND SUSCEPTIBILITY OF SOILS TO DEGRADATION IN THE BRAZILIAN SEMIARID REGION

Abstract

The relationship between specific pedogenic processes with soil vulnerability to degradation in the Northeastern semiarid region of Brazil is not yet well understood. This relationship is important duo to the possibility of subsidizing interventions and public policies in agreement with local specificities, which may contribute to mitigate and/or reverse the current situation of soil degradation. The aim of this study was to evaluate the relationship between specific pedogenic processes and soil vulnerability to land degradation and/or desertification in the microregions of Seridó and Cariri, located in Rio Grande do Norte and Paraíba states, respectively. Soil classes of these areas were identified by overlaying updated soil maps based on previous soil survey reports on heavily degraded areas. These areas are mainly associated with Abruptic Luvisol (Clayic) and Dystric Regosol (Locamic) in the Seridó and Haplic Luvisol (Clayic) and Eutric Regosol (Loamic) in the Cariri. Abrupt textural difference increases the vulnerability of Luvisols and Planosols to erosive processes. The anthrossolization can accelerate erosion, salinization, sodification, and solodization, causing soil loss, reducing soil physical quality, and siltation of water bodies. The relationship between specifics pedogenetic processes and land degradation can be better understood by assessing soils at higher categorical levels (subgroup).