Highlands of the upper Jequitinhonha valley, Brazil: I - characterization and classification

Abstract

SUMMARYIn the upper Jequitinhonha valley, state of Minas Gerais, Brazi, there are large plane areas known as "chapadas", which are separated by areas dissected by tributaries of the Jequitinhonha and Araçuaí rivers. These dissected areas have a surface drainage system with tree, shrub, and grass vegetation, more commonly known as "veredas", i.e., palm swamps. The main purpose of this study was to characterize soil physical, chemical and morphological properties of a representative toposequence in the watershed of the Vereda Lagoa do Leandro, a swamp near Minas Novas, MG, on "chapadas", the highlands of the Alto Jequitinhonha region Different soil types are observed in the landscape: at the top -Typic Haplustox (LVA), in the middle slope -Xanthic Haplustox (LA), at the footslope -Xanthic Haplustox, gray color, here called "Gray Haplustox" ("LAC") and, at the bottom of the palm swamp -Typic Albaquult (GXbd). These soils were first morphologically described; samples of disturbed and undisturbed soils were collected from all horizons and subhorizons, to evaluate their essential physical and chemical properties, by means of standard determination of Fe, Al, Mn, Ti and Si oxides after sulfuric extraction. The contents of Fe, Al and Mn, extracted with dithionite-citrate-bicarbonate and oxalate treatments, were also determined. In the well-drained soils of the slope positions, the typical morphological, physical and chemical properties of Oxisols were found. The GXbd sample, from the bottom of the palm swamp, is grayish and has high texture gradient (B/A) and massive structure. The reduction of the proportion of crystalline iron compounds and the low crystallinity along the slope confirmed the loss of iron during pedogenesis,

Chemical-Mineralogical Characterization of Magnetic Materials from Magnetic Soils of the Southern Espinhaço Mountain Chain and of the Upper Jequitinhonha Valley, State of Minas Gerais, Brazil

“…Highly weathered Oxisols have saturation baselines lower than 43 % (Table 2). Ferreira et al (2010) and Bispo et al (2011a) obtained similar values in Oxisol toposequences of UVJ plateaus.…”

“…The intermediate and high levels of silt/clay ratios of the RKox and TAoll, respectively, reflect a lower weathering stage, especially in the TAoll (Resende et al, 2007). Ferreira et al (2010) and Bispo et al (2011a) also found low values for the silt/clay ratio of Oxisols for the UVJ, as well as Silva et al (2005) for Oxisols for the SdEM.…”

“…In the SdEM, there are the rupestre vegetation types (Silva et al, 2005); semideciduous forest fragments at the borders of the "Chapadas" can be found in UVJ (Bispo et al, 2011a).…”

Caracterização e classificação de gleissolos da várzea do rio Solimões (Manacapuru e Iranduba), Amazonas, Brasil

“…Tais características, provavelmente, estão relacionadas ao processo de redução química e transporte do ferro no perfil, como consequência dos períodos de alagamentos nesse sistema, corroborando outros estudos que também destacam a forte influência da flutuação do lençol freático sobre as propriedades morfológicas do solo (Lima et al, 2006;Bispo et al, 2011).…”

Microbiological Attributes of Soil Under Spontaneous Restoration

“…Soils in the study areas are classified as Red Yellow Latosols, except for one type of soil in the plots studied in Cerrado, which is Red Latosol. However, both are typical dystrophic clayey soils and have similar physical, chemical, mineralogical and morphological attributes (Bispo et al, 2011).…”