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| Registros recuperados: 15 | |
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| Siqueira,Diego Silva; Marques Júnior,José; Teixeira,Daniel De Bortoli; Matias,Sammy Sidney Rocha; Camargo,Livia Arantes; Pereira,Gener Tadeu. |
| Abstract The objective of this work was to evaluate the use of magnetic susceptibility for characterizing the spatial variability of soil attributes and identifying areas with different potentials for sugarcane (Saccharum spp.) production. Samples were collected at 110 points (1 per 7 ha) in the layers of 0.00-0.20 and 0.20-0.40 m, to determine the magnetic susceptibility and physical and chemical attributes of the soil. Fiber content, sucrose polarization (POL), and sugarcane yield were determined in 33 points. The spatial variability model for magnetic susceptibility was 63 and 22% more accurate in delimiting soil potential for sugarcane production than soil physical and chemical attributes at the 0.0-0.2 and 0.2-0.4-m layers, respectively. The spatial... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Detailed mapping; Geostatistics; Indirect quantification; Pedometrics; Scaled semivariogram; Spatial correlation. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2016000901349 |
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| Oliveira,Ismênia Ribeiro de; Teixeira,Daniel De Bortoli; Panosso,Alan Rodrigo; Júnior,José Marques; Pereira,Gener Tadeu. |
| O objetivo deste trabalho foi avaliar o desempenho da simulação sequencial gaussiana (SSG) e da simulação sequencial indicatriz (SSI) na modelagem da incerteza das predições do K disponível em área de cana-de-açúcar, e comparar as simulações com o método já consagrado de krigagem ordinária (KO). Uma malha amostral com 626 pontos foi instalada em área de 200 ha, no Município de Tabapuã, em São Paulo. As simulações reproduziram a variabilidade dos dados amostrais de K disponível, enquanto a KO superestimou os baixos teores de K e subestimou os altos. O mapa de desvio-padrão obtido a partir da KO mostrou menor variação ao longo da área de estudo, quando comparado aos mapas obtidos a partir das simulações. A SSI obteve acurácia 22% superior à obtida pela SSG,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fertilidade do solo; Geoestatística; Krigagem; Simulação sequencial gaussiana; Simulação sequencial indicatriz; Variabilidade espacial.. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2014000900708 |
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| Dantas,Jussara Silva; Filho,Marcílio Vieira Martins; Júnior,José Marques; Resende,José Maria do Amaral; Teixeira,Daniel De Bortoli; Barbosa,Ronny Sobreira; Siqueira,Diego Silva. |
| O objetivo deste trabalho foi estimar o coeficiente de erodibilidade em sulcos e entressulcos, por meio de parâmetros da cor do solo. Foram selecionadas três áreas cultivadas com soja, em Argissolos Amarelos coesos do Leste Maranhense. Em cada área, foram retiradas 121 amostras na profundidade de 0,00-0,20 m. Foram determinados os valores de espectroscopia de reflectância difusa na faixa do visível, para obtenção dos valores de matiz, valor e croma. A partir destes constituintes da cor, foi calculado o índice de avermelhamento para cada amostra. Foram desenvolvidos modelos para avaliar o efeito de cada componente da cor sobre a erodibilidade em sulcos e entressulcos. Esses componentes apresentaram R2 que variou de 0,37 a 0,70. Os modelos gerados obtiveram... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cerrado; Erosão do solo; Espectroscopia de reflectância difusa; Formação Barreiras; Funções de pedotransferência; Pedometria.. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2014000900700 |
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| Teixeira,Daniel De Bortoli; Bicalho,Elton da Silva; Panosso,Alan Rodrigo; Perillo,Luciano Ito; Iamaguti,Juliano Luciani; Pereira,Gener Tadeu; La Scala Jr,Newton. |
| The soil CO2 emission has high spatial variability because it depends strongly on soil properties. The purpose of this study was to (i) characterize the spatial variability of soil respiration and related properties, (ii) evaluate the accuracy of results of the ordinary kriging method and sequential Gaussian simulation, and (iii) evaluate the uncertainty in predicting the spatial variability of soil CO2 emission and other properties using sequential Gaussian simulations. The study was conducted in a sugarcane area, using a regular sampling grid with 141 points, where soil CO2 emission, soil temperature, air-filled pore space, soil organic matter and soil bulk density were evaluated. All variables showed spatial dependence structure. The soil CO2 emission... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil respiration; Geostatistics; Ordinary kriging; Sequential Gaussian simulation; Sugarcane. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832012000500010 |
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| Barbieri,Diogo Mazza; Marques Júnior,José; Siqueira,Diego Silva; Teixeira,Daniel De Bortoli; Panosso,Alan Rodrigo; Pereira,Gener Tadeu; La Scala Junior,Newton. |
| Improvements in working conditions, sustainable production, and competitiveness have led to substantial changes in sugarcane harvesting systems. Such changes have altered a number of soil properties, including iron oxides and organic matter, as well as some chemical properties, such as the maximum P adsorption capacity of the soil. The aim of this study was to characterize the relationship between iron oxides and the quality of organic matter in sugarcane harvesting systems. For that purpose, two 1 ha plots in mechanically and manually harvested fields were used to obtain soil samples from the 0.00-0.25 m soil layer at 126 different points. The mineralogical, chemical, and physical results were subjected to descriptive statistical analyses, such as the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Degree of humification; Geochemistry; Soil management; Sustainable agriculture. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832014000400010 |
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| Mendonça,Patrícia Gabarra; Teixeira,Daniel De Bortoli; Moitinho,Mara Regina; Silva Junior,João Fernandes da; Oliveira,Ismênia Ribeiro de; Martins Filho,Marcílio Vieira; Marques Junior,José; Pereira,Gener Tadeu. |
| 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 Tabapuã, São Paulo State, Brazil. A regular 626-point sampling grid was established in the area, with equidistant intervals of 50 m and a final plant density of about 3.3 samples per ha. The probability that the soil loss would exceed the tolerable limit of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Green cane; Burnt cane; Geostatistics; Indicator kriging. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832018000100512 |
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| Aquino,Renato Eleotério de; Campos,Milton César Costa; Marques Junior,José; Oliveira,Ivanildo Amorim de; Teixeira,Daniel De Bortoli; Cunha,José Maurício da. |
| There is a great lack of information from soil surveys in the southern part of the State of Amazonas, Brazil. The use of tools such as geostatistics may improve environmental planning, use and management. In this study, we aimed to use scaled semivariograms in sample design of soil physical properties of some environments in Amazonas. We selected five areas located in the south of the state of Amazonas, Brazil, with varied soil uses, such as forest, archaeological dark earth (ADE), pasture, sugarcane cropping, and agroforestry. Regular mesh grids were set up in these areas with 64 sample points spaced at 10 m from each other. At these points, we determined the particle size composition, soil resistance to penetration, moisture, soil bulk density and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Sample density; Spatial variability; Physical properties; Scaled semivariograms. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000100021 |
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| Silva Junior,João Fernandes da; Marques Júnior,José; Camargo,Livia Arantes; Teixeira,Daniel De Bortoli; Panosso,Alan Rodrigo; Pereira,Gener Tadeu. |
| Os minerais da fração argila, goethita e hematita, são óxidos de ferro (Fe) indicadores pedoambientais com grande influência nos atributos físicos e químicos do solo. O conhecimento dos padrões espaciais desses óxidos auxilia a compreensão das interrelações de causa e efeito com os atributos do solo. Nesse sentido, a qualidade das estimativas espaciais produzidas pode alterar os resultados obtidos e, por consequência, as interpretações dos padrões espaciais obtidos. O presente estudo teve o objetivo de avaliar o desempenho dos métodos geoestatísticos de estimativas (KO) e simulações sequenciais gaussianas (SSG) na caracterização espacial de teores de óxidos de Fe, goethita (Gt) e hematita (Hm), em uma pedoforma côncava e outra convexa. Foram coletadas 121... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Goethita; Hematita; Krigagem ordinária; Acurácia; Pedometria. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832012000600003 |
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| Pereira,Gener Tadeu; Souza,Zigomar Menezes de; Teixeira,Daniel De Bortoli; Montanari,Rafael; Marques Júnior,José. |
| The sampling scheme is essential in the investigation of the spatial variability of soil properties in Soil Science studies. The high costs of sampling schemes optimized with additional sampling points for each physical and chemical soil property, prevent their use in precision agriculture. The purpose of this study was to obtain an optimal sampling scheme for physical and chemical property sets and investigate its effect on the quality of soil sampling. Soil was sampled on a 42-ha area, with 206 geo-referenced points arranged in a regular grid spaced 50 m from each other, in a depth range of 0.00-0.20 m. In order to obtain an optimal sampling scheme for every physical and chemical property, a sample grid, a medium-scale variogram and the extended Spatial... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Simulation; Geostatistics; Sugar cane. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832013000500002 |
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| Mendonça,Patrícia Gabarra; Silva Júnior,João Fernandes da; Oliveira,Ismênia Ribeiro de; Teixeira,Daniel De Bortoli; Moitinho,Mara Regina; Martins Filho,Marcílio Vieira; Marques Júnior,José; Pereira,Gener Tadeu. |
| The assessment of spatial uncertainty in the prediction of nutrient losses by erosion associated with landscape models is an important tool for soil conservation planning. The purpose of this study was to evaluate the spatial and local uncertainty in predicting depletion rates of soil nutrients (P, K, Ca, and Mg) by soil erosion from green and burnt sugarcane harvesting scenarios, using sequential Gaussian simulation (SGS). A regular grid with equidistant intervals of 50 m (626 points) was established in the 200-ha study area, in Tabapuã, São Paulo, Brazil. The rate of soil depletion (SD) was calculated from the relation between the nutrient concentration in the sediments and the chemical properties in the original soil for all grid points. The data were... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Green cane harvesting; Burnt cane harvesting; Geostatistics; Landforms; Sequential Gaussian simulation. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000401181 |
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| Resende,José Maria do Amaral; Marques Júnior,José; Martins Filho,Marcilio Vieira; Dantas,Jussara Silva; Siqueira,Diego Silva; Teixeira,Daniel De Bortoli. |
| A demanda nacional e internacional por mapas de atributos do solo tem aumentado. Os objetivos deste trabalho foram caracterizar e associar a variabilidade da granulometria, os atributos químicos e a cor de solos coesos a diferentes formas de paisagem, em áreas agrícolas e de vegetação nativa, por meio de técnicas geoestatísticas. Para a instalação do experimento, foram escolhidas três áreas representadas por uma área cultivada com soja e, contígua a essa, uma com cobertura vegetal remanescente de três feições de cerrado, designadas de Cerradão (A), Cerrado (B) e Campo Cerrado (C). As áreas A e B estão localizadas em pedoforma côncava e a área C, na convexa. Em cada área, foram estabelecidas malhas de amostragem com 121 pontos; nas áreas com cobertura... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Geoestatística; Espectroscopia de reflectância difusa; Cerrado. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832014000400004 |
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| Bahia,Angélica Santos Rabelo de Souza; Marques Júnior,José; Panosso,Alan Rodrigo; Camargo,Livia Arantes; Siqueira,Diego Silva; Teixeira,Daniel De Bortoli; Scala Júnior,Newton La. |
| Soil CO2 emission (FCO2) is one of the main sources of carbon release into the atmosphere. Moreover, FCO2 is related to soil attributes governing the transfer of gases from soil to the atmosphere. This study aimed firstly to describe the spatial variability of hematite (Hm), goethite (Gt), iron extracted with sodium dithionite-citrate-bicarbonate (Fed) contents, soil CO2 emission (FCO2) and free-water porosity (FWP) and secondly, to develop statistical models to predict the above mentioned factors in an Oxisol cultivated under manual harvesting of sugarcane (Saccharumspp.) in southeastern Brazil. The study was conducted on an irregular 50 m × 50 m grid containing 89 points, each 0.5-10 m apart. The 0-0.1 m soil layer at each sampling point was used to... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Hematite; Goethite; Soil respiration; Geostatistics; Cross-semivariograms. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162015000200157 |
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| Teixeira,Daniel De Bortoli; Bicalho,Elton da Silva; Panosso,Alan Rodrigo; Cerri,Carlos Eduardo Pellegrino; Pereira,Gener Tadeu; Scala Júnior,Newton La. |
| Soil CO2 emission (FCO2) is governed by the inherent properties of the soil, such as bulk density (BD). Mapping of FCO2 allows the evaluation and identification of areas with different accumulation potential of carbon. However, FCO2 mapping over larger areas is not feasible due to the period required for evaluation. This study aimed to assess the quality of FCO2 spatial estimates using values of BD as secondary information. FCO2 and BD were evaluated on a regular sampling grid of 60 m × 60 m comprising 141 points, which was established on a sugarcane area. Four scenarios were defined according to the proportion of the number of sampling points of FCO2 to those of BD. For these scenarios, 67 (F67), 87 (F87), 107 (F107) and 127 (F127) FCO2 sampling points... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Geostatistics; Cokriging; Ordinary kriging; Cross-variogram. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162013000300008 |
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| Leal,Fábio Tiraboschi; França,Ana Beatriz Coelho; Siqueira,Diego Silva; Teixeira,Daniel De Bortoli; Marques Júnior,José; Scala Júnior,Newton La. |
| ABSTRACTSoil CO2 emissions (fCO2) in agricultural areas have been widely studied in global climate change research, but its characterization and quantification are restricted to small areas. Because spatial and time variability affect emissions, tools need to be developed to predict fCO2 for large areas. This study aimed to investigate soil magnetic susceptibility (MS) and its correlation with fCO2 in an agricultural environment. The experiment was carried out on a Typic Eutrudox located in Guariba-SP, Brazil. Results showed that there was negative spatial correlation between fCO2 and the magnetic susceptibility of Air Dried Soil (MSADS) up to 34.3 m distant. However, the fCO2 had no significant correlation with MSADS, magnetic susceptibility of sand... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Magnetism; Soil respiration; Spatial variability; Geostatistics. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162015000600535 |
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| Registros recuperados: 15 | |
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