Caracterização e classificação de solos da porção central da bacia hidrográfica do rio Itapemirim, estado do Espírito Santo

Abstract

The Itapemirim River Hydrographic Basin – BHRI is the largest basin in the south of the state of Espírito Santo. It is divided into different geoenvironments along its entire length. Among them, the macroenvironments Celina and Cachoeiro form the central portion of the Basin, which are characterized by the heterogeneity of environmental factors, mainly soil formation factors such as rocks, relief and climate. Based on this assumption, this work aims to characterize representative soils of the middle portion of the Itapemirim River Basin – BHRI. For this, samples were collected from 15 soil profiles and their respective horizons were separated and samples were collected for further classification up to the fourth categorical level. Thus, the dissertation was divided into a chapter that consists of the physiographic characterization of the places where the soils were collected in BHRI from their morphometric characteristics and also the characterization of the chemical, physical, mineralogical and trace elements of the collected and related soils. them with their respective genesis. For this, the geology, altimetry, water balance, fault density, slope and geomorphology were studied in order to analyze the influence of these factors on the characteristics of the collected soil classes. Routine chemical and physical analyzes were also performed, as well as the digestion and reading of trace elements and X-ray diffraction. As a result, it was found that climate and relief influence soil fertility. It was also found that geology and relief were the main responsible for the appearance of a greater diversity of soil classes in low altitude units. The attributes revealed that most of the collected soils have a high degree of weathering, which can be seen through the low silt/clay ratios and the predominance of kaolinite and gibbsite in the XRD of the clay fraction. In these soils there was greater chemical poverty, but in the soils collected in a depression unit, they presented higher natural fertility rates.