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| Registros recuperados: 159 | |
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| Avanzi,Junior Cesar; Viola,Marcelo Ribeiro; Mello,Carlos Rogério de; Giongo,Marcos Vinicius; Pontes,Lucas Machado. |
| ABSTRACT The state of Tocantins is inserted in the new Brazilian agricultural frontier and has shown enormous potential for expansion of the agricultural lands. However, there is a lack of more elaborate scientific information for better planning and guide agricultural activities, especially regarding the soil and water conservation. Tocantins has a relevant rainfall spatial variability and, consequently, rainfall erosivity. Thus, this work aimed to develop models to estimate the mean monthly and annual rainfall and means rainfall erosivity factor (R-factor) of the Universal Soil Loss Equation (USLE) for the state of Tocantins. For that, 97 historical series of daily rainfall were studied, considering a standard period of 25 years (1985-2009). The fitting... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Water erosion; Geostatistics; Regression-kriging; Soil and water conservation; Mapping. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832019000100524 |
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| Seidel,Enio Júnior; Oliveira,Marcelo Silva de. |
| ABSTRACT: In geostatistical studies, spatial dependence can generally be described by means of the semivariogram or, in complementary form, with a single index followed by its categorization to classify the degree of such dependence. The objective of this study was to construct a categorization for the spatial dependence index (SDI) proposed by Seidel and Oliveira (2014) in order to classify spatial variability in terms of weak, moderate, and strong dependence. Theoretical values were constructed from different degrees of spatial dependence, which served as a basis for calculation of the SDI. In view of the form of distribution and SDI descriptive measures, we developed a categorization for posterior classification of spatial dependence, specific to each... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Geostatistics; Spatial dependence; Spatial variability; Semivariogram; Summary measures. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832016000100313 |
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| Corrêa,Adriany Rodrigues; Montanari,Rafael; Laura,Valdemir Antônio; Melotto,Alex Marcel; Silva,Evelize Nayara Santana da; Pellin,Douglas Martins Pereira; Santos,Anderson Secco dos. |
| In Brazil, grazing mismanagement may lead to soil and pasture degradation. To impede this process, integrated cropping systems such as silvopasture have been an effective alternative, allied with precision agriculture based on soil mapping for site-specific management. In this study, we aimed to define the soil property that best sheds light on the variability of eucalyptus and forage yield. The experiment was conducted in the 2011/12 crop year in Ribas do Rio Pardo, Mato Grosso do Sul State, Brazil. We analyzed linear and spatial correlations between eucalyptus traits and physical properties of a Typic Quartzipsamment at two depths (0.00-0.10 and 0.10-0.20 m). For that purpose, we set up a geostatistical grid for collection at 72 points. Gravimetric... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Geostatistics; Resistance to penetration; Soil management; Agricultural sustainability. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000200438 |
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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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| Luciano,Rodrigo Vieira; Albuquerque,Jackson Adriano; Mafra,Álvaro Luiz; Costa,André da; Grah,Josué. |
| In the subtropical regions of southern Brazil, rainfall distribution is uneven, which results in temporal variability of soil water storage. For grapes, water is generally available in excess and water deficiency occurs only occasionally. Furthermore, on the Southern Plateau of Santa Catarina, there are differences in soil properties, which results in high spatial variability. These two factors affect the composition of wine grapes. Spatio-temporal analyses are therefore useful in the selection of cultural practices as well as of adequate soils for vineyards. In this way, well-suited areas can produce grapes with a more appropriate composition for the production of quality wines. The aim of this study was to evaluate the spatio-temporal variability of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cambisol; Vitis vinifera L.; Geostatistics; Spatial variability; Temporal variability. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832014000100008 |
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| Chagas,César da Silva; Carvalho Júnior,Waldir de; Pinheiro,Helena Saraiva Koenow; Xavier,Pedro Armentano Mudado; Bhering,Silvio Barge; Pereira,Nilson Rendeiro; Calderano Filho,Braz. |
| ABSTRACT: Planning sustainable use of land resources requires reliable information about spatial distribution of soil physical and chemical properties related to environmental processes and ecosystemic functions. In this context, cation exchange capacity (CEC) is a fundamental soil quality indicator; however, it takes money and time to obtain this data. Although many studies have been conducted to spatially quantify soil properties on various scales and in different environments, not much is known about interactions between soil properties and environmental covariates in the Brazilian semiarid region. The goal of this study was to evaluate the efficiency of random forest and cokriging models applied to predict CEC in the Brazilian semiarid region. The... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Data mining; Geostatistics; Landsat 5; Legacy data; Soil survey. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832018000100311 |
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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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| Silva,Samuel de Assis; Lima,Julião Soares de Souza. |
| Information underlying analyses of coffee fertilization systems should consider both the soil and the nutritional status of plants. This study investigated the spatial relationship between phosphorus (P) levels in coffee plant tissues and soil chemical and physical properties. The study was performed using two arabica and one canephora coffee variety. Sampling grids were established in the areas, and the points georeferenced. The assessed properties of the soil were levels of available phosphorus (P-Mehlich), remaining phosphorus (P-rem) and particle size, and of the plant tissue, phosphorus levels (foliar P). The data were subjected to descriptive statistical analysis, correlation analysis, cluster analysis, and probability tests. Geostatistical and trend... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Coffee; Remaining P; Cokriging; Geostatistics. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832014000500009 |
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| Chioderoli,Carlos Alessandro; Mello,Luiz Malcom Mano de; Noronha,Rafael Henrique de Freitas; Pariz,Cristiano Magalhães; Lima,Ronaldo Cintra. |
| The Technologies setting at Agricultural production system have the main characteristics the vertical productivity, reduced costs, soil physical, chemical and biological improvement to promote production sustainable growth. Thus, the study aimed to determine the variability and the linear and special correlations between the plant and soil attributes in order to select and indicate good representation of soil physical quality for forage productivity. In the growing season of 2006, on the Fazenda Bonança in Pereira Barreto (SP), the productivity of autumn corn forage (FDM) in an irrigated no-tillage system and the soil physical properties were analyzed. The purpose was to study the variability and the linear and spatial correlations between the plant and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil physical properties; Soil management; Geostatistics; No-tillage; Forage crops. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832012000300008 |
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| Dalchiavon,Flávio Carlos; Carvalho,Morel de Passos e; Montanari,Rafael; Andreotti,Marcelo. |
| It is well-known nowadays that soil variability can influence crop yields. Therefore, to determine specific areas of soil management, we studied the Pearson and spatial correlations of rice grain yield with organic matter content and pH of an Oxisol (Typic Acrustox) under no- tillage, in the 2009/10 growing season, in Selvíria, State of Mato Grosso do Sul, in the Brazilian Cerrado (longitude 51º24' 21'' W, latitude 20º20' 56'' S). The upland rice cultivar IAC 202 was used as test plant. A geostatistical grid was installed for soil and plant data collection, with 120 sampling points in an area of 3.0 ha with a homogeneous slope of 0.055 m m-1. The properties rice grain yield and organic matter content, pH and potential acidity and aluminum content were... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Precision agriculture; Soil fertility; Geostatistics; Spatial variability; Oryza sativa. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832013000100005 |
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| Lima,Sandra Santana; Ceddia,Marcos Bacis; Zuchello,Fernando; Aquino,Adriana Maria de; Mercante,Fábio Martins; Alves,Bruno José Rodrigues; Urquiaga,Segundo; Martius,Christopher; Boddey,Robert Michael. |
| Epigeous termite mounds are frequently observed in pasture areas, but the processes regulating their population dynamics are poorly known. This study evaluated epigeous termite mounds in cultivated grasslands used as pastures, assessing their spatial distribution by means of geostatistics and evaluating their vitality. The study was conducted in the Cerrado biome in the municipality of Rio Brilhante, Mato Grosso do Sul, Brazil. In two pasture areas (Pasture 1 and Pasture 2), epigeous mounds (nests) were georeferenced and analyzed for height, circumference and vitality (inhabited or not). The area occupied by the mounds was calculated and termite specimens were collected for taxonomic identification. The spatial distribution pattern of the mounds was... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Termites; Isoptera; Geostatistics; Spatial distribution. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000100049 |
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| Nebel,Álvaro Luiz Carvalho; Timm,Luís Carlos; Cornelis,Wim; Gabriels,Donald; Reichardt,Klaus; Aquino,Leandro Sanzi; Pauletto,Eloy Antonio; Reinert,Dalvan José. |
| The estimation of non available soil variables through the knowledge of other related measured variables can be achieved through pedotransfer functions (PTF) mainly saving time and reducing cost. Great differences among soils, however, can yield non desirable results when applying this method. This study discusses the application of developed PTFs by several authors using a variety of soils of different characteristics, to evaluate soil water contents of two Brazilian lowland soils. Comparisons are made between PTF evaluated data and field measured data, using statistical and geostatistical tools, like mean error, root mean square error, semivariogram, cross-validation, and regression coefficient. The eight tested PTFs to evaluate gravimetric soil water... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil water content; Planosol; Gleisol; Hydraulic properties; Geostatistics; Regression models. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832010000300008 |
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| Silva,Raimunda Alves; Siqueira,Glécio Machado; Costa,Mayanna Karlla Lima; Guedes Filho,Osvaldo; Silva,Ênio Farias de França e. |
| ABSTRACT Geostatistics allows the evaluation of the distribution pattern of data with high spatial variability in agricultural systems. This study aimed to evaluate the spatial variability of biological diversity indices of soil fauna under different land (agriculture and forest). Samples were collected in seven areas (millet, soybean, corn, eucalyptus, pasture crops, and preserved and disturbed Cerrado), in Maranhão state, Brazil. The soil fauna was caught trapped in pitfall traps, installed 3 m away from each other. In each area, 130 traps were maintained for seven days. After this period, they were removed and their content transferred to bottles and taken to the laboratory, where the insects were screened and identified at the level of orders and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil biodiversity; Soil properties; Geostatistics. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832018000100409 |
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| Oliveira,Ivanildo Amorim de; Campos,Milton César Costa; Marques Junior,José; Aquino,Renato Eleotério de; Teixeira,Daniel de Bortoli; Silva,Douglas Marcelo Pinheiro da. |
| The lack of information concerning the variability of soil properties has been a major concern of researchers in the Amazon region. Thus, the aim of this study was to evaluate the spatial variability of soil chemical properties and determine minimal sampling density to characterize the variability of these properties in five environments located in the south of the State of Amazonas, Brazil. The five environments were archaeological dark earth (ADE), forest, pasture land, agroforestry operation, and sugarcane crop. Regular 70 × 70 m mesh grids were set up in these areas, with 64 sample points spaced at 10 m distance. Soil samples were collected at the 0.0-0.1 m depth. The chemical properties of pH in water, OM, P, K, Ca, Mg, H+Al, SB, CEC, and V were... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Geostatistics; Amazonian soils; Archaeological dark earth; Sampling density. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000100031 |
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| Gontijo,Ivoney; Souza Dias Junior,Moacir de; Guimarães,Paulo Tácito Gontijo; Oliveira,Marcelo Silva de; Ajayi,Ayodele Ebenezer. |
| Information on the spatial structure of soil physical and structural properties is needed to evaluate the soil quality. The purpose of this study was to investigate the spatial behavior of preconsolidation pressure and soil moisture in six transects, three selected along and three across coffee rows, at three different sites under different tillage management systems. The study was carried out on a farm, in Patrocinio, state of Minas Gerais, in the Southeast of Brazil (18 º 59 ' 15 '' S; 46 º 56 ' 47 '' W; 934 m asl). The soil type is a typic dystrophic Red Latosol (Acrustox) and consists of 780 g kg-1 clay; 110 g kg-1 silt and 110 g kg-1 sand, with an average slope of 3 %. Undisturbed soil cores were sampled at a depth of 0.10-0.13 m, at three different... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Semivariogram; Soil compaction; Geostatistics; Soil sampling. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832011000400012 |
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| Registros recuperados: 159 | |
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