Solos e geoambientes do Pantanal da Nhecolândia - MS

Abstract

Located in the center of South America, the Pantanal is a vast floodplain. The flood cycle is related to the plateaus, where are the sources of its main tributaries. It is considered a large tectonic fill plain. The wide variation of its hydrological regime, together with the redistribution of sediments by wind and river rework, creates a wide variety of soils, which, in their majority, are affected by hydromorphism. The present work aims to characterize the geoenvironments of the Nhecolândia sub-region, aiming to assist in themost efficient and integrated environmental management with the specificities of the region. 16 profiles were described and sampled and 5 geoenvironments were defined. The soil samples were subjected to physical and chemical analysis. Principal Component Analysis (PCA) was performed with the chemical and physical variables of the soils. In saline lagoons, typical Sodium Gleisols were found, with a clayey texture and high Sodium Saturation Index (ISNa). In the bays, two types of soil were found: Planossolo Háplico and Neossolo Quartzarêncio. The first has properties that resemble it with the saline soils and the second, that resembles it with the mountain ranges. As for the mountain ranges, in the murundus fields, Neossolos Quartzarêncios were described. The environments of lower altitudes present a finer texture and greater natural fertility, while the soils of the intermediate and higher areas are sandy, more acidic and of less natural fertility. In addition, the predominance of sandy soils is consistent with the fact that Nhecolândia is a deposition fluviolacustral plain, which receives predominantly sandy sediments from the surrounding highlands.