Spodosols pedogenesis under barreiras formation and sandbank environments in the south of Bahia

Abstract

SUMMARYMorphologically differentiated Spodosols usually occur in the Coastal Plain of the South of Bahia and North of Espírito Santo. They are found in profiles known as "muçungas", i.e. sandy soils that accumulate water. In these areas, two kinds of Spodosols, different from those in the Restinga area, can be found: Spodosols with E albic horizon (white muçunungas) and without this horizon (black muçunungas). Eight soil profiles with spodic characteristics were collected and described in order to evaluate differences in the formation process of Barreiras and Restinga Spodosols in the South of Bahia. The soil profiles were also characterized chemically, physically and mineralogically. Additionally, texture and chemical analysis, Fe and Al extraction by sodium dithionite-citrate-bicarbonate (DBC), acid ammonium oxalate and sodium pyrophosphate, ammonium oxalate extract optic density (DOox), sulphuric acid attack, and X ray difractometry of the clay fraction were performed. In the Spodosols of the Barreiras area, fragipan was found the spodic layers. Cemented B spodic horizon were observed in the white muçunungas, and granular structure and dark color from the surface in the black muçunungas. There was no fragipan or hard spodic horizon in the Restinga Spodosol. This soil is acid, dystrophic and alic, with sandy texture and high clay percentages in the spodic horizons. The CEC, based on H + Al, is predominantly represented by the organic matter. The most representative components of the mineral phase of the clay fraction are kaolinite and possibly vermiculite traces with interlayered hydroxy.

Characterization and classification of soils in the Taquari river basin - Pantanal region, state of Mato Grosso do Sul, Brazil

“…the transition between horizons in P4 was abrupt and plain, while in P3, the topography is flat, and differentiation ranged from abrupt to gradual. in both areas studied, a marked influence of the podzolization process was observed, by which organic compounds in solution that complex metal ions such as fe and/or al or not, were translocated into subsurface layers, due to variations in the water table (andriesse, 1969;Mokma & evans, 1999;dias et al, 2003;oliveira et al, 2010;Coelho et al, 2010). the soils studied were characterized by an albic e horizon (embrapa, 2006), suggesting an intense podzolization process.…”

“…in the surface horizons (h, a1 and a2) of the two profiles, the highest levels of Ca 2+ , Mg 2+ and h + were observed, reflecting higher values of sum of bases (sB) and cation exchange capacity (CeC). the highest CeC in the surface horizons was associated with organic matter, primarily responsible for the cation exchange capacity in sandy soils (embrapa, 2006), as well as in spodosols (dias et al, 2003;oliveira et al, 2010;Coelho et al, 2010). in this environment, the occurrence of Ca 2+ and Mg 2+ accumulation in subsurface horizons Bhs3 and Bhs4 (P1) and Bhs1, Bhs2, 2Bhs3 and 2Bhs4 (P2) is noteworthy, resulting in base saturation values of > 50 %.…”

“…in Brazil, spodosols are typically related to coastal environments and restinga vegetation (oliveira et al, 2010;Coelho et al, 2010), but also occur in large areas in the amazon on lower slopes with shrub vegetation and sediments with high sand content, as observed in the region of rio negro (Klinge, 1965;lucas et al, 1984, 1987Bravard & righi, 1989;righi et al, 1990).…”

Ametryn Leaching in Soils from the Sugarcane Region in Northeastern Brazilian

“…Spodosols are mineral, hydromorphic soils, and most of them present cemented horizons that restrict water infiltration and, as a consequence, also stop or hinder organic compounds to be leached out of the system, thus contributing to the podzolization process (Oliveira et al, 2010). …”

Podzolização em solos de áreas de depressão de topo dos tabuleiros costeiros do Nordeste brasileiro

“…As condições de paisagem e material de origem são aquelas consideradas relevantes ao processo de podzolização nos trópicos, como: relevo plano e, ou, suavemente abaciado; material de origem arenoquartzoso (inerte); e camadas de impedimento em subsuperfície, representadas por uma conjunção de horizontes cimentados e lençol freático suspenso (Gomes et al, 2007;Oliveira et al, 2010;Silva et al, 2012). O processo em si se sobrepõe em grande parte ao encontrado para Podzois não boreais, por Sauer et al (2007) e definidos por Buurman & Jongmans (2005), envolvendo materiais de origem pobres, matéria orgânica recalcitrante e translocação de complexos Fehúmus e Al-húmus.…”