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Pedogenesis in an Archaeological Dark Earth – Mulatto Earth Catena over Volcanic Rocks in Western Amazonia, Brazil

Luís Antônio Coutrim dos Santos, Jane Kelly Silva Araujo, Valdomiro Severino de Souza Júnior, Milton César Costa Campos, Marcelo Metri Corrêa, Regilene Angélica da Silva Souza

31/Jul/2018

ABSTRACT Archaeological Dark Earth (ADE) pedogenesis and pre-Columbian history are fundamental for understanding the biodiversity and pedodiversity of the Neotropical rainforest in the Amazon region. This study aimed to evaluate the morphological, physical, chemical, and mineralogical properties as well as NaOH-extractable organic matter [OM(NaOH)] in ADE and Mulatto Earth (ME) overlying volcanic rocks along a toposequence (four soil profiles) in western Amazonia, Brazil. The soil profiles show anthropic A horizons over an argic horizon (Bt) in the ADE (Humic, Pretic […]

Mineralogy, Micromorphology, and Genesis of Soils with Varying Drainage Along a Hillslope on Granitic Rocks of the Atlantic Forest Biome, Brazil

Anderson Almeida Pacheco, João Carlos Ker, Carlos Ernesto Gonçalves Reynaud Schaefer, Mauricio Paulo Ferreira Fontes, Felipe Vaz Andrade, Eder de Souza Martins, [...]

06/Jul/2018

ABSTRACT Although the physical environment of the Atlantic Forest realm is well known, studies on the soil-landform relationships are fundamental to improve the management of soil resources to facilitate sustainable development. The purpose of this study was to evaluate a representative topossequence on the “Mares de Morros” landscape of deeply weathered regolith on leucocratic granite rocks and demi-orange convex slopes. The soils varied along the topossequence according to drainage and were classified as Acrudox, Pseudogleysol, and Epiaquent. The clay fraction […]

Reversibility of the Hardening Process of Plinthite and Petroplinthite in Soils of the Araguaia River Floodplain under Different Treatments

Angélica Pires Batista Martins, Glenio Guimarães Santos, Virlei Álvaro de Oliveira, Deyvid Diego Carvalho Maranhão, Leonardo Santos Collier

18/Jun/2018

ABSTRACT Although ferruginous materials occur frequently in soils of tropical regions, information about the reversal of the hardening process of these materials is scarce. This study assessed the influence of different chemical treatments and periods of immersion on the reversibility of the hardening process of plinthite and petroplinthite in soils of the Araguaia River plain. Soil samples were collected from the plinthic horizons in 0.10 m high and 0.15 m diameter PVC cylinders and divided into subsamples with a rock […]

Multinomial Logistic Regression and Random Forest Classifiers in Digital Mapping of Soil Classes in Western Haiti

Wesly Jeune, Márcio Rocha Francelino, Eliana de Souza, Elpídio Inácio Fernandes Filho, Genelício Crusoé Rocha

18/Jun/2018

ABSTRACT Digital soil mapping (DSM) has been increasingly used to provide quick and accurate spatial information to support decision-makers in agricultural and environmental planning programs. In this study, we used a DSM approach to map soils in western Haiti and compare the performance of the Multinomial Logistic Regression (MLR) with Random Forest (RF) to classify the soils. The study area of 4,300 km2 is mostly composed of diverse limestone rocks, alluvial deposits, and, to a lesser extent, basalt. A soil […]

Hardening and Stability of Plinthic Materials of the Araguaia River Floodplain under Different Drying Treatments

Angélica Pires Batista Martins, Glenio Guimarães Santos, Virlei Álvaro de Oliveira, Deyvid Diego Carvalho Maranhão, Leonardo Santos Collier

20/Apr/2018

ABSTRACT Plinthite and petroplinthite occur frequently in Brazilian soils, but there is little information on the behavior of these materials. The aim of the present study was to assess the effect of different drying periods on the hardening and stability of plinthic materials of soils in the floodplain of the Araguaia River and the João Leite stream in Goiás. Soil samples were collected, with the aid of 0.10 m high and 0.15 m diameter PVC cylinders, directly from the plinthic […]

Prediction of Topsoil Texture Through Regression Trees and Multiple Linear Regressions

Helena Saraiva Koenow Pinheiro, Waldir de Carvalho, César da Silva Chagas, Lúcia Helena Cunha dos Anjos, Phillip Ray Owens

04/Apr/2018

ABSTRACT: Users of soil survey products are mostly interested in understanding how soil properties vary in space and time. The aim of digital soil mapping (DSM) is to represent the spatial variability of soil properties quantitatively to support decision-making. The goal of this study is to evaluate DSM techniques (Regression Trees – RT and Multiple Linear Regressions – MLR) and the ability of these tools to predict mineral fraction content under a wide variability of landscapes. The study site was […]

Spatial Disaggregation of Multi-Component Soil Map Units Using Legacy Data and a Tree-Based Algorithm in Southern Brazil

Israel Rosa Machado, Elvio Giasson, Alcinei Ribeiro Campos, José Janderson Ferreira Costa, Elisângela Benedet da Silva, Benito Roberto Bonfatti

02/Mar/2018

ABSTRACT Soil surveys often contain multi-component map units comprising two or more soil classes, whose spatial distribution within the map unit is not represented. Digital Soil Mapping tools supported by information from soil surveys make it possible to predict where these classes are located. The aim of this study was to develop a methodology to increase the detail of conventional soil maps by means of spatial disaggregation of multi-component map units and to predict the spatial location of the derived […]

Pedological Studies of Subaqueous Soils as a Contribution to the Protection of Seagrass Meadows in Brazil

Gabriel Nuto Nóbrega, Danilo Jefferson Romero, Xosé Luis Otero, Tiago Osório Ferreira

05/Feb/2018

ABSTRACT: Seagrass meadows are considered one of the most important and valuable ecosystems on the planet, but also one of the most threatened. Missing knowledge about their existence and their subtidal nature are the main reasons for the lack of information about seagrass soils, especially in Brazil and other tropical areas. This study discussed the paradoxical lack of information about subaqueous soils, with a view to stimulate research on soil properties of seagrass meadows. This short communication provides information about […]

Slash Spatial Linear Modeling: Soybean Yield Variability as a Function of Soil Chemical Properties

Regiane Slongo Fagundes, Miguel Angel Uribe-Opazo, Luciana Pagliosa Carvalho Guedes, Manuel Galea

05/Feb/2018

ABSTRACT: In geostatistical modeling of soil chemical properties, one or more influential observations in a dataset may impair the construction of interpolation maps and their accuracy. An alternative to avoid the problem would be to use most robust models, based on distributions that have heavier tails. Therefore, this study proposes a spatial linear model based on the slash distribution (SSLM) in order to characterize the spatial variability of soybean yields as a function of soil chemical properties. The likelihood ratio […]

Surface Spectroscopy of Oxisols, Entisols and Inceptisol and Relationships with Selected Soil Properties

Raúl Roberto Poppiel, Marilusa Pinto Coelho Lacerda, Manuel Pereira de Oliveira, José Alexandre Melo Demattê, Danilo Jefferson Romero, Marcus Vinicius Sato, [...]

19/Jan/2018

ABSTRACT: Traditional method of soil survey is expensive, slow, and must be carried out by experienced researchers. Thus, advances in soil observation technologies and the need to obtain information quickly by modern techniques have intensified the use of proximal sensing. This study characterized surface reflectance spectra (A horizon) and related them to traditional soil classification, based on morphological, physical, and chemical properties of representative pedogenetic profiles, developed in two toposequences of the Distrito Federal, Brazil. In the toposequences, 15 soil […]

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