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| Registros recuperados: 159 | |
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| Silva,Kátia Araújo da; Rodrigues,Marcos Sales; Moreira,Filipe Bernard Ramos; Lira,Aíris Layanne Ferreira; Lima,Augusto Miguel Nascimento; Cavalcante,Ítalo Herbert Lucena. |
| Abstract Soil sampling is a fundamental procedure in the decision making regarding the management of the soil, thus, a sampling plan should represent as accurately as possible the evaluated crop field. Therefore, the objectives of this study were to suggest a soil sampling approach and soil sampling point allocation using spatial analyses and compare to the classic statistic method in irrigated mango orchards in the Brazilian semi-arid region. The experiment was carried out in three commercial mango orchards located in the region of the São Francisco Valley, Brazil. Soil samples were collected in 0-0.2 m and 0.2-0.4 m depths following regular grids where the number of samples varied from 50 to 56. Soil texture, soil bulk density, soil total porosity,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Geostatistics; Mangifera indica L; Semivariogram; Spatial dependence. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452020000503003 |
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| Silva,Rodrigo Gregório da; Neiva,José Neuman Miranda; Santos,Antonio Clementino dos; Cândido,Magno José Duarte; Sousa,Antonio Luiz Dias; Lopes,Marcos Neves; Silva,Rafael de Oliveira da; Carneiro,Leovegildo Caldas. |
| The objective of this study was to identify the pattern of deposition of feces by supplemented crossbred dairy cows after the lactation peak on cultivated areas under levels of intensification of the system and its effects on nitrogen cycling, with the aid of geostatistics, in the rainy period. Treatments were composed of two levels of nitrogen fertilization (equivalent to 400 and 800 kg N/ha/year) and two types of animals, according to the daily milk production. Geostatistical and descriptive analyses of the data were conducted. The data presented positive coefficients of skewness and platykurtic kurtosis. For the coefficient of variation, there was elevated alteration, with rest areas showing higher values and paddocks with a higher level of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Geostatistics; Nitrogen fertilization; Nutrient cycling; Pasture; Supplementation. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982013000500010 |
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| Pariz,Cristiano Magalhães; Carvalho,Morel de Passos e; Chioderoli,Carlos Alessandro; Nakayama,Fernando Takayuki; Andreotti,Marcelo; Montanari,Rafael. |
| The objective of this study was to analyze variability, linear and spatial correlations of forage dry mass yield (FDM) and dry matter percentage (DM%) of Brachiaria decumbens with the bulk density (BD), gravimetric (GM) and volumetric (VM) moisture, mechanical resistance to penetration (RP) and organic matter content (OM), at depths 1 (0-0.10 m) and 2 (0.10-0.20 m), in a Red Latosol (Oxisol), in order to select an indicator of soil physical quality and identify possible causes of pasture degradation. The geostatistical grid was installed to collect soil and plant data, with 121 sampling points, over an area of 2.56 ha. The linear correlation between FDM × DM% and FDM × BD2 was low, but highly significant. Spatial correlations varied inversely and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bulk density; Geostatistics; Gravimetric and volumetric moisture; Mechanical resistance to penetration; Organic matter. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982011001000007 |
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| Lima,Julião Soares de Sousa; Alves,Danielle Inácio; Coelho,Ruimário Inácio; Sturião,Walas Permanhane; Silva,Samuel Assis. |
| ABSTRACT Leaf analysis is widely used to study the nutritional status of plants, based on the fact of there being a direct correlation between rate of growth and the nutrient levels in leaf tissue. This study was carried out on a commercial crop of Golden THB papaya, in the north of the State of Espirito Santo, Brazil, to determine the spatial variability of nutrients in the petiole of leaf samples collected when carrying out sexing in a regular grid of 129 georeferenced points. Harvesting was carried out manually 270-365 days after transplanting. All the characteristics displayed a strong spatial dependence, the spherical and exponential semivariograms being adjusted for the data. The greatest and smallest ranges were found for the micronutrients Mn and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Geostatistics; Semivariogram; Leaf petiole. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902016000200264 |
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| Cherubin,Maurício Roberto; Santi,Antônio Luis; Eitelwein,Mateus Tonini; Da Ros,Clovis Orlando; Bisognin,Mateus Bortoluzi. |
| Knowledge of spatial variability is an important factor to be considered in planning a program of soil sampling and crop management under precision agriculture (PA). In this context, the aim of this work was to evaluate the efficiency of the dimensions of sampling grids used in the state of Rio Grande do Sul (RS), Brazil to characterise the spatial variability of the attributes pHwater, base saturation (V%), calcium (Ca) and magnesium (Mg) levels. The study was carried out on 30 agricultural sites located in the northern region of RS, having soils classified as Oxisols and managed using the tools of PA. The dimensions of the grids under study were: 100 x 100 m (10 areas), 142 x 142 m (10 areas) and 173 x 173 m (10 areas). Soil was collected at a depth of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil acidity; Precision Agriculture; Soil sampling; Geostatistics. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902014000400004 |
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| Oliveira,Mara Lucia Jacinto; Valladares,Gustavo Souza; Vieira,Johnston Silva; Coelho,Ricardo Marques. |
| ABSTRACT The aim of the present work was to: (i) determine and map the micronutrient content (copper - Cu, iron - Fe, manganese - Mn and zinc - Zn) in soils of the State of Ceará; (ii) evaluate soil attributes related to micronutrient availability; and (iii) evaluate, by ordinary kriging, the spatial dependence of the micronutrient content. The study area is located in the central region of Ceará, in the basin of the River Banabuiú. Soil samples were collected in the surface and subsurface layers to determine the chemical attributes, granulometry, and micronutrient content, extracted with Mehlich-1 solution. The sites of the principal types of soil in the region were spatialised and the results submitted to descriptive analysis and Pearson correlation... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cationic micronutrients; Geostatistics; Ordinary kriging; Soils of the semi-arid region. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902018000300371 |
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| Barbosa,Danilo Pereira; Bottega,Eduardo Leonel; Valente,Domingos Sárvio Magalhães; Santos,Nerilson Terra; Guimarães,Wellington Donizete; Ferreira,Matheus de Paula. |
| ABSTRACT The proper handling soil allows the reduction of contaminants, maximize agricultural productivity, and is directly related the knowledge spatial variability of soil attributes. This spatial variability can express isotropic and anisotropic form. The latter being neglected in research related to management zones delineation. In this context, the present study aimed to evaluate the effect of the geometric anisotropy correction on the management zone delineation. The methodology was applied under database of soybean productivity and apparent electrical conductivity (CEa) of a rural property in Ponta Porã - MS. By means of this georeferenced database, maps was interpolated with ordinary kriging. For each combination, attribute (productivity and CEa)... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Geostatistics; Anisotropy factor; Spatial variability; Apparent electrical conductivity; Soybean. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902019000400543 |
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| Lucena,Isabela Codolo de; Amorim,Ricardo Santos Silva; Lobo,Francisco de Almeida; Baldoni,Raquel Negrão; Matos,Dalva Maria da Silva. |
| In areas of the Cerrado-Pantanal ecotone in Brazil, the soil displays features which are inherent to the processes of soil formation, both of the Central Plateau and the Pantanal Plain. Given this premise, the area should be noteworthy for its high level of edaphic heterogeneity. The present study aimed to determine the physical, chemical and physico-hydric attributes that best explain the heterogeneity of soils in areas of the Cerrado-Pantanal ecotone, and to assess whether these attributes differ between the studied fragments and between the Cerrado soils of the Central Plateau and of the Pantanal Plain. One hundred and sixty soil samples were collected and 11 profiles described for five areas of the Cerrado-Pantanal ecotone (15º43' S, 56º04' W). The... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Physicochemical attributes; Geostatistics; Plinthosols; Latosols. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902014000400005 |
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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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| Souza,Zigomar Menezes de; Marques Júnior,José; Pereira,Gener Tadeu; Barbieri,Diogo Mazza. |
| Soils with small variations in relief and under the same management system present differentiated spatial variabilities of their attributes. This variability is a function of soil position in the landscape, even if the relief has little expression. The aim of this work was to investigate the effects of relief shape and depth on spatial variability of soil chemical attributes in a Typic Hapludox cultivated with sugar cane at two landscape compartments. Soil samples were collected in the intercrossing points of a grid, in the traffic line, at 0-0.2 m and 0.6-0.8 m depths, comprising a set of 100 georeferenced points. The spatial variabilities of pH, P, K, Ca, Mg, cation exchange capacity and base saturation were quantified. Small relief shape variations lead... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Geostatistics; Kriging; Relief; Sugar cane. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162006000200008 |
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| Ribeiro Jr,Paulo Justiniano; Viola,Denise Nunes; Demétrio,Clarice Garcia Borges; Manly,Bryan F.; Fernandes,Odair Aparecido. |
| Onion (Allium cepa) is one of the most cultivated and consumed vegetables in Brazil and its importance is due to the large laborforce involved. One of the main pests that affect this crop is the Onion Thrips (Thrips tabaci), but the spatial distribution of this insect, although important, has not been considered in crop management recommendations, experimental planning or sampling procedures. Our purpose here is to consider statistical tools to detect and model spatial patterns of the occurrence of the onion thrips. In order to characterize the spatial distribution pattern of the Onion Thrips a survey was carried out to record the number of insects in each development phase on onion plant leaves, on different dates and sample locations, in four rural... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Poisson distribution; Spatial statistics; Randomization tests; Geostatistics. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162009000100013 |
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| Curi,Thayla Morandi Ridolfi de Carvalho; Conti,Dante; Vercellino,Rimena do Amaral; Massari,Juliana Maria; Moura,Daniella Jorge de; Souza,Zigomar Menezes de; Montanari,Rafael. |
| ABSTRACT Ventilation systems are incorporated at intensive poultry farms to control environment conditions and thermal comfort of broilers. The ventilation system operates based on environmental data, particularly measured by sensors of temperature and relative humidity. Sensors are placed at different positions of the facility. Quality, number and positioning of the sensors are critical factors to achieve an efficient performance of the system. For this reason, a strategic positioning of the sensors associated to controllers could support the maintenance and management of the microclimate inside the facility. This research aims to identify the three most representative points for the positioning of sensors in order to support the ventilation system during... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Broiler farms; Environmental control; Geostatistics; Ordinary kriging; Welfare. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162017000200101 |
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| Ceddia,Marcos Bacis; Vieira,Sidney Rosa; Villela,André Luis Oliveira; Mota,Lenilson dos Santos; Anjos,Lúcia Helena Cunha dos; Carvalho,Daniel Fonseca de. |
| Among the soil formation factors, relief is one of the most used in soil mapping, because of its strong correlation with the spatial variability of soil attributes over a landscape. In this study the relationship between topography and the spatial variability of some soil physical properties was evaluated. The study site, a pasture with 2.84 ha, is located near Seropédica, Rio de Janeiro State, Brazil, where a regular square grid with 20 m spacing was laid out and georreferenced. In each sampling point, altitude was measured and undisturbed soil samples were collected, at 0.0-0.1, 0.1-0.2, and 0.2-0.3 m depths. Organic carbon content, soil texture, bulk density, particle density, and soil water retention at 10 (Field Capacity), 80 (limit of tensiometer... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Terrain elevation; Geostatistics; Soil physics; Cross semivariance. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162009000300009 |
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| Molin,José Paulo; Faulin,Gustavo Di Chiacchio. |
| Soil electrical conductivity (ECa) is a soil quality indicator associated to attributes interesting to site-specific soil management such as soil moisture and texture. Soil ECa provides information that helps guide soil management decisions, so we performed spatial evaluation of soil moisture in two experimental fields in two consecutive years and modeled its influence on soil ECa. Soil ECa, moisture and clay content were evaluated by statistical, geostatistical and regression analyses. Semivariogram models, adjusted for soil moisture, had strong spatial dependence, but the relationship between soil moisture and soil ECa was obtained only in one of the experimental fields, where soil moisture and clay content range was higher. In this same field,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Precision agriculture; Soil physics; Geostatistics; Soil sensors. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162013000100001 |
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| Grego,Célia Regina; Vieira,Sidney Rosa; Lourenção,André Luiz. |
| The knowledge of the spatial distribution of insect populations in crops allows the estimation of the population density in space, the classification of damage impact on yield as well as decisions to be made about control measures. To evaluate the spatial distribution of the wheat armyworm Pseudaletia sequax Franclemont, in relation to the development and yield of triticale (Triticum secale Wittmack) under no-till management, samplings were taken at 302 points in a square grid measuring 10 x 10 m, in Campinas, SP, Brazil. The caterpillar population was evaluated by counting their number per meter at the base of triticale plants. Grain yield (kg ha-1), cover of the above-ground part (kg ha-1), mean plant height (m), and ground cover percentage were... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Triticum secale Wittmack; Insecta; Wheat armyworm; Geostatistics; Indicator kriging. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162006000400002 |
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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: 159 | |
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