363 results

Geochemistry and Spatial Variability of Rare Earth Elements in Soils under Different Geological and Climate Patterns of the Brazilian Northeast

Cinthia Maria Cordeiro Atanázio Cruz Silva, Ronny Sobreira Barbosa, Clístenes Williams Araújo do Nascimento, Yuri Jacques Agra Bezerra da Silva, Ygor Jacques Agra Bezerra da Silva

18/jun/2018

ABSTRACT Growth in the agricultural and industrial sectors has increased the demand for rare earth elements (REEs) in the production of technological devices and fertilizers. Thus, the accumulation of these elements in the soil has become an environmental concern. Here, we aim to determine the natural contents of REEs in soils derived from different parent materials and under climatic conditions ranging from humid to semi-arid. We then evaluate the influence of major elements and soil properties on the geochemistry of […]

Water Erosion in Oxisols under Coffee Cultivation

Henrique Mendes Júnior, André Silva Tavares, Walbert Reis dos Santos Júnior, Marx Leandro Naves Silva, Breno Régis Santos, Ronaldo Luiz Mincato

18/jun/2018

ABSTRACT Water erosion is one of the main environmental impacts of land use. When soil and water losses occur, nutrients essential for the growth and maintenance of plants are removed, with harmful outcomes on the sustainability of agriculture and the environment. In addition, they lead to other deleterious effects, such as sedimentation and eutrophication of water bodies. Estimation of soil losses due to water erosion in sub-basins is essential for prediction of soil degradation, especially in areas of semi-intensive cultivation, […]

Relationship between Coffee Leaf Analysis and Soil Chemical Analysis

Jailson Silva Sousa, Júlio César Lima Neves, Herminia Emilia Prieto Martinez, Víctor Hugo V. Alvarez

29/maio/2018

ABSTRACT: Research focused on adequate nutrition of plants is essential in modern coffee production to increase yield and develop more efficient management strategies with greater environmental and economic sustainability. The objectives of this study were to establish critical and optimal levels of soil fertility properties for high yielding Arabica coffee crops using the Boundary Line method and, then, relate the macronutrient contents in the diagnostic leaf of coffee to the macronutrients available in the soil using the Quadrant Diagram of […]

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, [...]

10/maio/2018

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 […]

Soil Erodibility under Natural Rainfall Conditions as the K Factor of the Universal Soil Loss Equation and Application of the Nomograph for a Subtropical Ultisol

Elemar Antonino Cassol, Tiago Stumpf da Silva, Flávio Luiz Foletto Eltz, Renato Levien

03/maio/2018

ABSTRACT: Erodibility represents the intrinsic susceptibility of the soil to the erosion process, represented by the K factor in the Universal Soil Loss Equation (USLE). In Brazil, there are few field experiments determined with a series larger than ten years of data, which are the most reliable for quantifying the K factor. The aim of this study was to determine the K factor of the USLE by the direct method, relating soil losses determined in the field under standard conditions […]

Nitrous Oxide Emissions in a Wheat/Corn Succession Combining Dairy Slurry and Urea as Nitrogen Sources

Celso Aita, Felipe Tonetto, Rogerio Gonzatto, Stefen Barbosa Pujol, Janquieli Schirmann, Juliano dos Santos Depoi, [...]

03/maio/2018

ABSTRACT: The impact on nitrous oxide (N2O) emissions caused by combining dairy slurry (DS) and urea to supply crops with nitrogen (N) is still not well characterized. The main objective of this study was to compare the differences between N2O emissions in the cases of exclusive use of urea and the combined use of DS and urea as N sources to no-tillage wheat and corn. We also compared N2O emissions between two DS application methods (surface-broadcast vs. injection), as well […]

Soil CH4 and N2O Emissions from Rice Paddy Fields in Southern Brazil as Affected by Crop Management Levels: a Three-Year Field Study

Tiago Zschornack, Carla Machado da Rosa, Cecília Estima Sacramento dos Reis, Gabriel Munhoz Pedroso, Estefânia Silva Camargo, Daiane Carvalho dos Santos, [...]

20/abr/2018

ABSTRACT Rice yield increases in response to improvements in crop management, but the impact on greenhouse gas (GHG) emissions in the subtropical region of Southern Brazil remains unknown. A three-year field study was developed aiming to evaluate the impact that an increase in crop management levels (high and very high) has on soil methane (CH4) and nitrous oxide (N2O) emissions, as compared to the level (medium) currently adopted by farmers in Southern Brazil. Differences in crop management included seed and […]

Reference Values of Soil Quality for the Rio Doce Basin

Yang Zumbo Coronel Guevara, José João Lelis Leal de Souza, Gustavo Vieira Veloso, Renato Welmer Veloso, Pablo Azevedo Rocha, Walter Antônio Pereira Abrahão, [...]

04/abr/2018

ABSTRACT: The great geological and soil variation in the state of Minas Gerais, Brazil, indicates the need for regional studies to understand the geochemical background of soils. The Rio Doce Basin became a priority area for geochemical background determination after the rupture of the tailings dam of Fundão in 2015. In this context, the objectives of this study were to propose Reference Values of Soil Quality in the Rio Doce Basin, to define variables that can predict metal(loid) concentrations in […]

Temporal and Spatial Uncertainty of Erosion Soil Loss from an Argisol Under Sugarcane Management Scenarios

Patrícia Gabarra Mendonça, Daniel De Bortoli Teixeira, Mara Regina Moitinho, João Fernandes da Silva, Ismênia Ribeiro de Oliveira, Marcílio Vieira Martins, [...]

23/mar/2018

ABSTRACT The identification of erosion-susceptible areas is fundamental for the adoption of soil conservation practices. Thus, the best way to estimate the spatial pattern of soil erosion must be identified, in which the process uncertainties are also taken into consideration. The purpose of this study was to evaluate the spatial and temporal uncertainty of soil loss under two scenarios of sugarcane harvest management: green cane (GC) and burnt cane (BC). The study was carried out on a 200-ha area, in […]

Metal-Resistant Rhizobacteria Change Soluble-Exchangeable Fraction in Multi-Metal-Contaminated Soil Samples

Cácio Luiz Boechat, Patricia Dörr de Quadros, Patrícia Giovanella, Ana Clecia Campos Brito, Filipe Selau Carlos, Enilson Luiz Saccol de Sá, [...]

23/mar/2018

ABSTRACT There is a complex interaction between various components of the soil ecosystem, including microbial biomass and soil chemical contaminants such as heavy metals and radionuclides, which may greatly affect the efficiency of bioremediation techniques. The aim of this study was to investigate microbial capacity to change pH, changes in the metal soluble-exchangeable fraction, and effects of initial heavy metal contents on soil samples in microbial solubilization/immobilization capacity. The soil samples used in this study were collected at a known […]

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