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

Abstract

suMMary among the soils in the Mato grosso do sul, stand out in the Pantanal biome, the spodosols. despite being recorded in considerable extensions, few studies aiming to characterize and classify these soils were performed. the purpose of this study was to characterize and classify soils in three areas of two physiographic types in the taquari river basin: bay and flooded fields. two trenches were opened in the bay area (P1 and P2) and two in the flooded field (P3 and P4). the third area (saline) with high sodium levels was sampled for further studies. in the soils in both areas the sand fraction was predominant and the texture from sand to sandy loam, with the main constituent quartz. in the bay area, the soil organic carbon in the surface layer (P1) was (oC) > 80 g kg -1 , being diagnosed as histic epipedon. in the other profiles the surface horizons had low oC levels which, associated with other properties, classified them as ochric epipedons. in the soils of the bay area (P1 and P2), the ph ranged from 5.0 to 7.5, associated with dominance of Ca 2+ and Mg 2+ , with base saturation above 50 % in some horizons. in the flooded fields (P3 and P4) the soil ph ranged from 4.9 to 5.9, h + contents were high in the surface horizons (0.8-10.5 cmol c kg -1 ), Ca 2+ and Mg 2 contents ranged from 0.4 to 0.8 cmol c kg -1 and base saturation was < 50 %. in the soils of the bay area (P1 and P2) iron was accumulated (extracted by dithionite -fed) and oC in the spodic horizon; in the P3 and P4 soils only fed was accumulated (in the subsurface layers). according to the criteria adopted by the Brazilian system of soil Classification (siBCs) at the subgroup level, the soils were classified as: P1: organic hydromorphic ferrohumiluvic spodosol. P2:(1) received for publication in January 5, 2011 and approved in March 2, 2012.(2) Professor associado iv da universidade estadual de Mato Grosso do sul -ueMs, departamento de solos. rodovia aquidauana, km 12, CeP 79200-000 aquidauana (Ms). e-mail: schiavo@uems.br (3) engenheiro agrônomo, Mestre em agronomia, Produção vegetal, ueMs. e-mail: tonybioagro@hotmail.com (4) Professor associado ii do departamento de solos da universidade federal rural do rio de Janeiro -ufrrJ. Br 465, km 7, CeP 23890-000 seropédica (rJ

Physical, chemical, and mineralogical attributes of a representative group of soils from the eastern Amazon region in Brazil

“…The Nitosols and Cambisols had high Fe concentrations. Ti oxides do not accumulate in specific geological formations, and this may be related to the low levels of Ti in the parent material and the isomorphic substitution of Ti during pedogenesis (Silva et al, 2013). The high concentration of Mn oxides is related to soils being collected in marsh deposits and Holocene mangroves.…”

“…The lower Feo / Fed ratio in the subsurface layer was due to high weathering that promotes the crystallization of iron oxides (Paisani et al, 2013) and results in low ratios between the amorphous and crystalline forms. The higher values in the topsoil layer may be related to the contributions of OC and the high exchangeability of the Al, which results in Fe complexation, inhibition of crystallization (Schiavo et al, 2012), and the favoring of the formation of low crystalline oxides.…”

Soil hydromorphy and soil carbon: A global data analysis

“…MAP ranged from minimum 127 mm year −1 in USA (Thompson et al, 2007) to maximum 3833 mm year −1 in a Bolivian tropical forest (Schawe et al, 2007), with an average of 1316 mm year −1 . MAT varied from minimum −1.6°C year −1 in temperate Russia (Sorokin et al, 2006) to 30.15°C in tropical Brazil (Schiavo et al, 2012). Soil pH was very acidic with a value of 2.5 in an alluvial wetland in Italy (Ferronato et al, 2016), while the other extreme was the basic soil with a pH value of 8.9 in a floodplain of a tropical forest in Brazil (Guimaraes et al, 2013).…”

“…Soil color also showed high variability with a respective coefficient of variation of 33% for Value and 75% for Chroma. Chroma ranged from 0 for some sites in Brazil, USA and China (Skorupa et al, 2013;Vepraskas and Caldwell, 2008;Kölb et al, 2014) to a maximum of 10 for a site in Brazil (Schiavo et al, 2012). Value varied from a minimum of 2 at sites in the US, Germany, Brazil and China (Vepraskas and Caldwell, 2008;Fiedler et al, 2002;Nascimento et al, 2004;Kölb et al, 2014) to a maximum of 8 reported for a site in Brazil (Martins et al, 2006).…”

Physical, chemical and mineralogical attributes of a representative group of soils from the Eastern Amazon, Brazil

“…The Feo/Fed ratio decreased in the sub-surface layer relative to the surface layer because high weathering promotes the crystallization of iron oxides (Paisani et al, 2013) and results in low ratios between the amorphous and crystalline forms. The higher values in the topsoil layer may be related 5 to the contributions of OC and the high exchangeable Al content, which results in Fe complexation and inhibits its crystallization (Schiavo et al, 2012), favoring the formation of low crystalline oxides.…”