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All publications of “Gustavo Souza Valladares”

7 results

Mineralogy and Concentration of Potentially Toxic Elements in Soils of the São Francisco Sedimentary Basin

Edilene Pereira Ferreira, Ricardo Marques Coelho, Gustavo Souza Valladares, Laura Milani da Silva Dias, Ana Carolina Cunha de Assis, Rafael Cipriano da Silva, [...]


ABSTRACT Lithological and geomorphological variations determine formation of soils with different mineralogical constitutions and can influence the distribution of potentially toxic elements (PTE). The aim of this study was to determine the contents of PTE and mineralogical assemblages along soil profiles of different classes and parent materials and to investigate the association among these factors in the São Francisco sedimentary basin in the northern part of the state of Minas Gerais (Brazil). Eight soil pedons of different classes that developed […]

Bulk Density Prediction for Histosols and Soil Horizons with High Organic Matter Content

Sidinei Julio Beutler, Marcos Gervasio Pereira, Wagner de Souza Tassinari, Michele Duarte de Menezes, Gustavo Souza Valladares, Lúcia Helena Cunha dos Anjos


ABSTRACT Bulk density (Bd) can easily be predicted from other data using pedotransfer functions (PTF). The present study developed two PTFs (PTF1 and PTF2) for Bd prediction in Brazilian organic soils and horizons and compared their performance with nine previously published equations. Samples of 280 organic soil horizons used to develop PTFs and containing at least 80 g kg-1 total carbon content (TOC) were obtained from different regions of Brazil. The multiple linear stepwise regression technique was applied to validate […]

Carbon and Nitrogen Stocks and Humic Fractions in Brazilian Organosols

Gustavo Souza Valladares, Marcos Gervasio Pereira, Vinícius de Melo Benites, Lúcia Helena Cunha dos Anjos, Adierson Gilvani Ebeling, Roni Fernandes Guareschi


ABSTRACT Despite limited geographic expression of Organosols in Brazil, their high carbon storage capacity and natural environmental vulnerability justifies further studies on C and N stocks in these soils and their relationship to the nature of organic matter. Evaluation of physical and chemical properties of organic soils and their ability to store C is important so as to develop sustainable management practices for their preservation. The objectives of the study were to measure the total organic carbon stock (OCst), total […]

Genesis and Classification of Soils Containing Carbonate on the Apodi Plateau, Brazil

Edilene Pereira Ferreira, Lúcia Helena Cunha dos Anjos, Marcos Gervasio Pereira, Gustavo Souza Valladares, Rafael Cipriano-Silva, Antônio Carlos de Azevedo


ABSTRACT Information is scarce on the genesis and classification of soils derived from calcareous rocks in the Northeastern region of Brazil. This study describes the morphological, physical, chemical, mineralogical, and micromorphological properties of four soil profiles (P1-P4) located in the Apodi Plateau. A pedogenesis hypothesis and soil classification, according to the Brazilian System of Soil Classification (SiBCS), are proposed for these profiles. The interactions between parent material, surface topography and climate affected the pedogenesis processes and soil properties, although the […]

Characterization of Histosols in floodplain environments in the northeast region of Brazil

Rafael Cipriano-Silva, Gustavo Souza Valladares, Marcos Gervasio Pereira, Lúcia Helena Cunha dos Anjos


The Histosols are generally associated with Southeastern and Southern regions of Brazil, and there are few studies on the occurrence and effects of the use and agricultural management of these soils in the Northeast. The aim of this paper is to physically, chemically and morphologically characterize six profiles of Histosols from flood plains in the states of Ceara, Rio Grande do Norte and Paraiba, Brazil and correlate their soil properties to the training environment, as well as quantify their carbon […]

Risk of land salinization in baixo Acaraú, Ceará

Lydia Helena da Silva de Oliveira Mota, Andréa da Silva Gomes, Gustavo Souza Valladares, Regina Maria Fontenele Magalhães, Hugo Mota Ferreira Leite, Tibério Almeida da Silva


Certain conditions of relief, climate and use can lead to the formation of saline and sodic soils, also called salt-affected soils. With a view to establish guidelines for management practices and land use in the region of Baixo Acaraú, Ceará, the purpose of this work was to generate a map of salinization risk. To classify levels of vulnerability, the pedology, geology, geomorphology and land use/cover were evaluated as well as slope altimetry information, treated in a GIS environment with an […]

Principal component analysis and ordinal multicriteria methods to study organosols and related soils

Gustavo Souza Valladares, Eliane Gonçalves Gomes, João Carlos C.B. Soares de Mello, Marcos Gervasio Pereira, Lúcia Helena Cunha dos Anjos, Adierson Gilvani Ebeling, [...]


One important property of Organosols (Histosols) (and soils with high content of organic carbon) to predict use potential and degradation risks is the degree of subsidence (loss of mass and volume). In Organosols the subsidence risks vary according to the soil attributes, mainly the nature of organic matter and deposition environment. In this paper we studied 19 soil profiles from different parts of the country, collected and described according to procedures recommended by the SBCS (Brazilian Soil Science Society); the […]