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68 results

Long-Term Effect of Soil Use and Management on Organic Carbon and Aggregate Stability

Neuro Hilton Wolschick, Fabrício Tondello Barbosa, Ildegardis Bertol, Bárbara Bagio, Danieli Schneiders Kaufmann

05/Sep/2018

ABSTRACT: The conversion of native grassland into farmland causes changes in the soil. Tillage has profound effects on soil organic matter. The intensification of soil tillage decreases soil quality by reducing aggregate stability. Soil aggregate stability and soil organic matter are key indicators for soil quality and environmental sustainability in agro-ecosystems. The aim of the present study is to evaluate the total organic carbon content and the physical and chemical fractions of the organic matter in a soil under different […]

Daycent Simulation of Methane Emissions, Grain Yield, and Soil Organic Carbon in a Subtropical Paddy Rice System

Douglas Adams Weiler, Carlos Gustavo Tornquist, Tiago Zschornack, Stephen Michael Ogle, Filipe Selau Carlos, Cimélio Bayer

18/Jun/2018

ABSTRACT The DayCent ecosystem model, widely tested in upland agroecosystems, was recently updated to simulate waterlogged soils. We evaluated the new version in a paddy rice experiment in Southern Brazil. DayCent was used to simulate rice yield, soil organic carbon (SOC), and soil CH4 fluxes. Model calibration was conducted with a multiple-year dataset from the conventional tillage treatment, followed by a validation phase with data from the no-tillage treatment. Model performance was assessed with statistics commonly used in modeling studies: […]

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, […]

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/May/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/May/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/Apr/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/Apr/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 […]

Relationship Among Crop Systems, Soil Cover, and Water Erosion on a Typic Hapludox

Pedro Luiz Terra Lima, Marx Leandro Naves Silva, John Norman Quinton, Pedro Velloso Gomes Batista, Bernardo Moreira Cândido, Nilton Curi

02/Mar/2018

ABSTRACT Several soil conservation practices are used to reduce water erosion and ensure sustainable agriculture. An effective crop management practice is intercropping, in which two or more crops with different architectures and vegetative cycles are grown simultaneously in the same area. We hypothesized that intercropping of corn and jack-bean increases soil cover and reduce soil erosion by water in comparison to monocropping. The objective of this study was to evaluate the effects of different crop systems on soil cover and […]

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