18 results

Genesis of Soils from Bauxite in Southeastern Brazil: Resilication as a Soil-Forming Process

Ana Carolina Campos Mateus, Fábio Soares de Oliveira, Angélica Fortes Drummond Chicarino Varajão, Caroline Cibele Vieira Soares

30/Oct/2017

ABSTRACT Pedological studies using X-ray diffraction (XRD), X-ray fluorescence (XRF), optical microscopy, and scanning electron microscopy (SEM-EDS) showed a Xanthic Ferralsol formed from the degradation of bauxite on a slope in the Caparaó region, in southeastern Brazil. We found a decrease in the number and size of bauxite fragments toward the top of the profiles, bauxite fragments that were more degraded at the top of the profiles, transformation of gibbsite into kaolinite, and absolute enrichment in silicon in the mass […]

Genesis and Classification of Sodic Soils in the Northern Pantanal

Jairo Calderari de Oliveira, Mariane Chiapini, Alexandre Ferreira do Nascimento, Eduardo Guimarães Couto, Raphael Moreira Beirigo, Pablo Vidal-Torrado

27/Sep/2017

ABSTRACT The simultaneous occurrence of high levels of exchangeable sodium percentage (ESP) and alkalinity in soils imposes restrictions on plant development and affects physical properties such as porosity, bulk density, permeability, and hydraulic conductivity. Although sodic soils are frequent in the flood plain of the São Lourenço River, northern Pantanal, Brazil, few studies focus on their formation and classification, especially with regard to specific processes and detailed classification into lower categorical levels by the different systems available. The aim of […]

Physical, Macro- and Micromorphological Properties of Regosols in the Agreste Meridional Region of Pernambuco, Brazil

Alison Van Der Linden de Almeida, Marcelo Metri Corrêa, José Romualdo de Sousa Lima, Eduardo Soares de Souza, Kleber Régis Santoro, Antonio Celso Dantas Antonino

01/Sep/2015

ABSTRACT Regosols in the Agreste Meridional region of Pernambuco, Brazil, are used for various agricultural activities, and prominent among them is production of common bean. An expressive variation is perceived in common bean crop yield, possibly associated with the presence of lamellae, which make for distinct water fluxes among these soils. The objective was to analyze the macro- and micromorphological, and physical characteristics of the Regosols located in the Agreste Meridional region of Pernambuco to understand the water fluxes in […]

Influence of tillage systems and simulated rainfall on the process of surface crust formation

Jaqueline Dalla Rosa, Miguel Cooper, Frédéric Darboux, João Carlos Medeiros

01/Apr/2013

On the soil surface, rainfall modifies the soil surface structure promoting crust development. This study evaluated the dynamics of soil crusting, through description and micromorphological analysis of thin sections in 2009 and 2010. In 15 x 30 m plots, the management systems conventional tillage (CT), reduced tillage (RT) and no tillage (NT) were assessed. Within the plots, 1 x 1 m micro-plots were installed to test different levels of simulated rainfall (0, 27, 54, and 80 mm) at an intensity […]

Influence of crust formation under natural rain on physical attributes of soils with different textures

Selene Cristina de Pierri Castilho, Miguel Cooper, Carlos Eduardo Pinto Juhász

01/Dec/2011

One of the main negative anthropic effects on soil is the formation of crusts, resulting in soil degradation. This process of physical origin reduces soil water infiltration, causing increased runoff and consequently soil losses, water erosion and/or soil degradation. The study and monitoring of soil crusts is important for soil management and conservation, mainly in tropical regions where research is insufficient to explain how soil crusts are formed and how they evolve. The purpose of this study was to monitor […]

Pedogenesis of planosols in a toposequence of the agreste region of Pernambuco, Brazil

Roberto da Boa Viagem Parahyba, Mauro Carneiro dos Santos, Fernando Cartaxo Rolim Neto, Paulo Klinger Tito Jacomine

01/Dec/2010

In the Agreste region of Pernambuco state, Planosols are economically highly important, due to the degree of occupation, as well as the heavy use, mainly for agricultural activities. Aspects such as duality or reworking of parent material, which characterize the processes involved in the formation of the marked textural differences and of Na and salt concentrations, are important points to be clarified. This study aimed to evaluate the pedogenetic process of the Planosols in the region Agreste, state of Pernambuco, […]

Quality of a latosol-argisol system in the county of Lins/SP, Brazil

Liliane Ibrahim, Adolpho José Melfi

01/Dec/2008

The purpose of this study was the characterization of a soil system, focused on proprieties that can clarify the dynamics and contribute to the definition of criteria that determine the ability of these soils as recipients of effluents. An experimental study area was used, adjacent to the Sewage Treatment Station of the municipality of Lins (SP), where the sewage is treated in a system of stabilization ponds. The soil samples, taken from five trenches in a toposequence of a slight […]

Oxisol toposequences developed from basaltic rocks in Paraná State, Brazil. II – relationship between clay fraction mineralogy and physical soil properties

André Ademir Ghidin, Vander de Freitas Melo, Valmiqui Costa Lima, Jane Maria Jonasson Costa Lima

01/Apr/2006

Soil structure (type, size and development) defines the total soil porosity and macro and microporosity distribution, and is considered to be one of the most important agricultural soil properties. The aim of this work was to study the effect of the clay fraction mineralogy, including the crystallographic mineral characteristics, in the soil physical properties of two Oxisols developed from the basaltic rocks, in different landscape positions (toposequence) in Paraná State, Brazil. With this objective, the soil profile was morphologically described […]

Agricultural machinery traffic and alterations in biopores under an orange orchard

Herdjania Veras de Lima, Cláudia Liane Rodrigues de Lima, Tairone Paiva Leão, Miguel Cooper, Alvaro Pires da Silva, Ricardo Espíndola Romero

01/Oct/2005

Soil micromorphological studies enable a detailed observation of the modifications in soil pore structure and space imposed by cultivation and agricultural machinery traffic. This study tested the hypothesis that compaction caused by machinery affects the form and class distribution of pores in a distinct way and that such alterations can be used as soil quality indicators. The objectives of this study were to evaluate and quantify, through micromorphological studies, the modifications in porosity caused by biological activity (biopores) in a […]

Mineralogy, morphology and microscopic analysis of soils of the cerrado biome

J. B. V. Gomes, N. Curi, D. G. Schulze, J. J. G. S. M. Marques, J. C. Ker, P. E. F. Motta

01/Aug/2004

The macro and micromorphological characteristics of the surface and subsurface diagnostic horizons of Oxisols and Quartzipsamments of the South American and Velhas geomorphic surfaces were analyzed in profiles under native vegetation cover, in order to establish a reference for future comparisons with similar areas under ongoing human intervention. The soils in their respective subregions and geomorphic surfaces were classified in three groups: Group 1: hypo to mesoferric, clayey to very clayey soils; Group 2: hypoferric; sandy to sandy loam soils, and Group 3: […]

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