Mateus Rosas Ribeiro Filho

Topossequência de solos na transição campos naturais-floresta na região de Humaitá, Amazonas

The objective of this work was to study soil-relief relations in a grassland-forest transition, in the region of Humaita, Amazonas State, Brazil. The study area was selected based on the criterion of regional representativity (most common landscape) and in the level of environmental preservation. The sample collection was carried out in a transect from the grassland towards the forest, and the different soil environments were identified and limited according relief position, vegetation patterns and soil characteristics. Soil profiles were morphologically characterized and samples collected from all horizons for physical and chemical analysis for normal profile characterization. including SiO2, Al2O3 and Fe2O3 extracted by H2SO4 attack, free iron oxides by DCB extraction and poor crystalline iron oxides extracted by ammonium oxalate. Mineralogical analysis was also carried out by X-ray diffraction. The results suggest that soil variation in the landscape was directly related with the relief, which determines soil drainage and water table level.

Relações solo-superfície geomórfica em uma topossequência várzea-terra firme na região de Humaitá (AM)

The geomorphic surface concept allows interrelationship among various branches of soil sciences, such as geology, geomorphology and pedology. The purpose of this study was to investigate soil-geomorphic surface relations along an upland-downland toposequence in the region of Humaita, Amazonas State, Brazil. A transect of 4,500 m was studied from the water divide downstream to the flood plain of the Madeira river. The geomorphic surfaces were identified based on the slope rupture, stratigraphic criteria and on other field observations. Trenches were dug in the identified slope segments, the soils were morphologically characterized and samples collected from each horizon. The physical properties particle size distribution, water dispersible clay and flocculation degree, soil and particle density, total porosity, and saturated hydraulic conductivity were determined. Chemical analysis involved pH in water and KCl; exchangeable Ca, Mg, K, Na, and Al; available P, Al + H and organic C; total SiO2, Al2O3 and Fe2O3 by sulfuric acid digestion; free iron oxides extracted with dithionite-citrate-bicarbonate and poor crystalline iron oxides with ammonium acid oxalate. The values of ∆pH, silt/clay, Ki and Fed/Fet ratio indicated more weathered soils at the top of the landscape, than along the infiltration slope, convex slope and alluvial footslope, coinciding with the older age of the soils of the geomorphic surface I than of II and III. The soil variations in the studied transect were related to the surface age, parent material and slope gradient. The understanding of the geomorphic events was important to explain the variation of soil properties in the toposequence.

Caracterização e classificação de terras pretas arqueológicas na Região do Médio Rio Madeira

Although several studies have been published about the Archaeological Dark Earths, few of them tried to understand and elucidate questions about the pedogenesis and behavior of these soils. Thus, the objective of this study was to characterize and classify Archaeological Dark Earths in four sites, selected in the region of the Middle Madeira River. Four pedons were morphologically characterized and collected for chemical, physical and mineralogical analysis. Physical analysis involved par- ticle size distribution, water dispersible clay, soil bulk and particle density, total porosity and saturated hydraulic conductivity. Chemical analysis involved pH in water and KCl, exchangeable cations, exchangeable aluminum, available P, extractable acid- ity (Al+H), organic carbon and, SiO 2 , Al 2 O 3 and Fe 2 O 3 extracted with H 2 SO 4 . Free iron oxides were extracted with dithionite- citrate-bicarbonate and poor crystalline iron oxides were extracted using ammonium acid oxalate. Mineralogical analysis of sand, silt and clay fractions were carried out by X-ray diffraction. The studied soils were classified in the Brazilian System of Soil Classification as Red Yellow Argisol, Gray Argisol and Yellow Argisol. The presence of the anthropogenic A horizons with similar chemical properties and depths in all studied sites suggests that similar conditions have influenced their formation. All anthropogenic horizons studied in the region showed high base saturation and high to very high P availability as compared to subjacent horizons. The inclusion of the anthropogenic subgroup in the Brazilian System of Soil Classification was also suggested.

Segmentos de vertente e atributos do solo de uma toposseqüência na região de Manicoré, AM

Variations of soil properties are consequence of several factors such as: climate, parent material, vegetation and, particularly relief, which controls runoff and drainage, and has influence in the exposure of parent materials to the weathering action. The objective of this work was to study the influence of the slope segments on soil attributes of a topossenquence in the Manicore region, AM. Twenty samples were collected in each of the several slope segments identified along a 3 km transect, from the top and toward the lower part of the topography. The slope segments and the sampling depths were: high top (0.0-0.19 and 0.37-0.60 m), medium slope (0.0-0.28 and 0.60-0.80 m); lower slope (0.0-0.15 and 0.42-0.71 m) and low top (0.0-0.15 and 0.20-0.40 m). The sampling depths were coincident with the surface and subsurface diagnostic horizons defined in the profile morphological description. Physical analysis involved particle size distribution, soil and particle density, total porosity and saturated hydraulic conductivity. In the chemical analysis pH in water and KCl, exchangeable cations, exchangeable Al, available P, H+Al, organic carbon were determined. The use of multivariate statistic techniques enabled the distinction of different soil geomorphic environments independent of the slope segments identifications. The relief variations contributed to the presence of dystrophic soils in the high top and eutrophic soils in the lower slope.

Interferências dos pedoambientes nos atributos do solo em uma topossequência de transição Campos/Floresta

The pedoenvironmental conditions promote changes in soil properties, so the aim of this work was to study Interference of the pedoenvironment on soil properties in a topossequence of the Grassland/Forest transition in the Humaita region, AM. Was picked up a topossequence characteristic sequence Grassland/Forest, then a pathway was established, from a field environment to the natural forest environment. These pedoambients were identified and defined as the expression patterns of vegetation. Were collected 20 samples at the representative side of the profiles in each one of the pedoambiental units of the topossequence (top grassland: 0.0-14 and 0.30-0.66 m;low grassland : 0.0-0.15 and 0.27-0.80 m; ecotone zone: 0.0-0.15 and 0.32-0.50 m; forest: 0.0-0.15 m 0.67-100 as a total of 80 samples) being the criteria for sampling depths the coincidence with the surface and subsurface diagnostic horizons determined by the morphological description of the profiles. Were performed physical analysis of texture, clay dispersion and flocculation, soil bulk density and particle porosity and hydraulic conductivity. In the chemical analysis were determined pH in water and KCl, Ca, Mg, K, Na and Al contents, available P, H + Al and organic carbon. The physical and chemical soil were dependent on the pedoambients. With the use of multivariate statistical techniques was possible to distinguish three different environments that are equivalent to three pedoambients.

Inorganic Materials as Ameliorants for Soil Remediation of Metal Toxicity to Wild Mustard (Sinapis arvensis L.)

The ameliorating effects of different inorganic materials were investigated on a soil originating from a zinc smelter dumping site contaminated by toxic metals. Wild mustard (Sinapis arvensis L.) was used as a test plant. The soil was amended with different doses of mining sludge, Perferric Red Latosol (LVj), steel shots, cyclonic ash, silifertil, and superphosphate. The most effective amendments improved plant growth with 45% and reduced metal uptake by over 70% in comparison to untreated soil. Reductions in availability as estimated by BaCl2-extractable metals reached up to 90% for Zn and 65% for Cd as compared to unamended soil. These reductions were associated with lower shoot and root metal contents. Shoot Zn content was reduced from 1,369 μg g−1 in plants grown on untreated soil to 377 μg g−1 when grown on cyclonic ash amended soil while Cd decreased from 267 to 44 μg g−1 in steel shots amended soil. Superphosphate addition had no ameliorating effect. On the contrary, it increased BaCl2-extractable amounts of Zn. Considering all parameters we determined, steel shots, cyclonic ash and silifertil are the most promising for remediating metal contaminated soil in the tropics. Further studies evaluating impacts, cost-effectiveness and durability of effects will be conducted.

Lead concentration and allocation in vegetable crops grown in a soil contaminated by battery residues

O chumbo (Pb) e um elemento extremamente estavel no solo e altamente toxico para seres humanos e animais. A contaminacao com chumbo geralmente ocorre pela exposicao decorrente da inalacao de particulas oriundas de industrias ou do solo, ou ainda, pela ingestao de poeira domestica, agua e alimentos de origem animal e vegetal contaminados. O presente trabalho objetivou avaliar os teores e a alocacao de Pb em hortalicas cultivadas em solo contaminado com residuos de reciclagem de baterias. O experimento foi conduzido em casa-de-vegetacao com delineamento experimental em blocos casualizados, com quatro repeticoes. Os tratamentos corresponderam a oito hortalicas: tomate, pimentao, beterraba, cenoura, repolho, couve manteiga, berinjela e quiabo. Os resultados mostraram que as especies mais tolerantes ao Pb foram cenoura, couve-manteiga, beterraba e quiabo. As demais hortalicas foram consideradas muito sensiveis aos teores de Pb no solo, nao completando inclusive seu ciclo biologico. A ordem decrescente de teores de Pb nas especies foi: cenoura > quiabo > tomate > berinjela > pimentao > couve-manteiga > repolho > beterraba. A alocacao do Pb na planta, seguiu a ordem geral: raiz > caule > folha > parte comestivel. Embora a cenoura tenha transferido baixo teor de Pb para a parte comestivel, o valor encontrado foi superior ao limite de tolerância maximo estabelecido na legislacao.