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Registros recuperados: 73 | |
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Guedes,Luciana P. C.; Ribeiro Junior,Paulo J.; Uribe-opazo,Miguel A.; Bastiani,Fernanda de. |
ABSTRACT This study aimed to compare thematic maps of soybean yield for different sampling grids, using geostatistical methods (semivariance function and kriging). The analysis was performed with soybean yield data in t ha-1 in a commercial area with regular grids with distances between points of 25x25 m, 50x50 m, 75x75 m, 100x100 m, with 549, 188, 66 and 44 sampling points respectively; and data obtained by yield monitors. Optimized sampling schemes were also generated with the algorithm called Simulated Annealing, using maximization of the overall accuracy measure as a criterion for optimization. The results showed that sample size and sample density influenced the description of the spatial distribution of soybean yield. When the sample size was... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Accuracy indices; Optimization; Sampling grids; Spatial variability. |
Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162016000100114 |
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Pereira,Priscilla A.; Yanagi Junior,Tadayuki; Silva,Joaquim P. da; Lima,Renato R. de; Campos,Alessandro T.; Abreu,Lucas H. P. |
The spatial distribution of illuminance and the electric consumption of artificial lighting system is one of the main problems related to broiler production. Therefore, the aim of this study was to evaluate the spatial distribution of luminance level and energy efficiency of different lighting systems for broiler houses. Six types of lamps were tested in two different configurations to find the minimum illuminance of 20 and 5 lux. The tested lamps were incandescent (IL) 100 W, compact fluorescent (CFL) 34 W, mixed (ML) 160 W, sodium vapor (SVL) 70 W, T8 fluorescent tube (T8 FTL) 40 W and T5 fluorescent tube (T5 FTL) 28 W. The first four were evaluated with and without reflective light fixture and the latter two without light fixture. It was observed that... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Artificial lighting; Spatial variability; Energy efficiency; Aviculture. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162012000600002 |
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Guedes,Luciana P. C.; Uribe-Opazo,Miguel A.; Ribeiro Junior,Paulo J.; Dalposso,Gustavo H.. |
ABSTRACT Spatial variability depends on the sampling configuration and characteristics associated with the georeferenced phenomenon, such as geometric anisotropy. This study aimed to determine the influence of the sampling design on parameter estimation in an anisotropic geostatistical model and the spatial estimation of a georeferenced variable at unsampled locations. Datasets were simulated with geometric anisotropy, considering five values for the anisotropic ratio (1, 2, 3, 4, 5), and three sampling designs: lattice, random and lattice plus close pairs. The simulation results were used as a reference to select anisotropic models to describe the spatial dependence structure in chemical soil properties. For each dataset (with either simulated or chemical... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bootstrap; Directional trend; Geostatistics; Spatial variability; Tests of isotropy. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000200260 |
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Farias,Vera L. da S.; Martins Filho,Marcílio V.; Paula,Daniela T. de; Siqueira,Diego S.. |
ABSTRACT Phosphorus losses in runoff water and eroded sediment may increase the risk of eutrophication. Erosion prediction models can be used to assess and quantify nutrient losses and transport in different soil management scenarios. This study aimed to assess the performance of models to estimate the losses of available phosphorus in eroded sediments and assess their spatial variability pattern. The experiment was installed on a eutrophic Red Ultisol located in Tabapuã, northwestern São Paulo State, São Domingos Stream Watershed. Aiming at estimating and validating the models, measurements were made from 2007 to 2015 at 17 observation points (slopes), determining soil phosphorus content (Psoil), eroded sediments (Psed), and enrichment rate (ERsed). The... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: WEPP model; Enrichment rate; Spatial variability. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000100149 |
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Gadotti,Gizele I.; Corrêa,Marciabela F.; Navroski,Renan; Nadal,Ariele P.; Schuch,Luis O. B.. |
ABSTRACT The aim of this research was to study the linear correlations and spatial distribution between soil attributes and productivity and physiological quality of wheat seeds. Soil samples were collected at georeferenced points in an area of 41 ha with a rectangular grid of 100 × 100 m to determine soil fertility. Grain productivity, number of ears m-2, protein content, and physiological seed quality were assessed. The results were submitted to Pearson's correlation analysis, descriptive statistics, and geostatistics. Phosphorus content presented a high spatial variability, with a coefficient of variation of 97.79%. Protein content, number of ears, and SMP index presented low values of coefficient of variation, indicating their low spatial variability.... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Precision agriculture; Fertility; Seed quality; Triticum aestivum L.; Spatial variability. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000400624 |
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GREGO, C. R.; PAIM, F. A. de P.; RODRIGUES, C. A. G.; CRISCUOLO, C.; GARCON, E. A. M.; MANJOLIN, R. C.; ALVAREZ, I. A.; ALBUQUERQUE, T. C. S. de. |
Este trabalho tem como objetivo o uso da análise geoestatística no mapeamento da fertilidade do solo de seis propriedades familiares do Circuito das Frutas, localizadas nos municípios de Itatiba, Atibaia, Jundiaí, Valinhos, Indaiatuba, Jarinú, no estado de São Paulo. |
Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E) |
Palavras-chave: Geoestatística; Variabilidade espacial; Krigagem ordinária; Culturas frutíferas; Spatial variability; Ordinary kriging; Fruticultura; Fertilidade do Solo; Geostatistics; Fruit crops. |
Ano: 2018 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/1102129 |
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Dang, C.; Sauriau, Pierre-guy; Savoye, N.; Caill-milly, Nathalie; Martinez, P.; Millaret, C.; Haure, Joel; De Montaudouin, X.. |
Spatial changes in the dietary regime of Ruditapes philippinarum from intertidal sediments of Arcachon Bay were depicted by analyzing stable isotope ratios in both its adductor muscles and potential trophic sources. Manila clams were collected from 50 sites in May to June 2006. Dietary reconstruction was based on the IsoSource mixing model, considering trophic enrichments of 3.5%. for carbon and 3.0%. for nitrogen, which were determined experimentally. delta C-13 and delta N-15 values, respectively, averaged -28.2 and 5.2 parts per thousand for riverine particulate organic matter (POM), -20.6 and 4.7 parts per thousand for inner bay phytoplankton, -21.0 and 5.6%. for outer bay phytoplankton, -16.8 and 4.8 parts per thousand. for microphytobenthos, -18.4... |
Tipo: Text |
Palavras-chave: SW France; Arcachon Bay; Spatial variability; Mixing model; Trophic sources; C and N stable isotopes; Muscle; Ruditapes philippinarum. |
Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/2009/publication-6886.pdf |
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Dubois, Stanislas; Orvain, Francis; Marin Leal, Julio César; Ropert, Michel; Lefebvre, Sébastien. |
Oyster culture structures support a host of epibionts belonging to the same suspension-feeding guild, which are considered to be potential competitors for food with cultivated oysters. In an intertidal shellfish ecosystem on the northern French coast, an approach based on stable isotopes (C-13 and N-15) was used to investigate intra- and interspecific food resource partitioning among cultivated oysters and the main associated wild sessile epibionts such as polychaetes, barnacles, mussels and ascidians. The main objective of the present study was to determine inter- and intraspecific food partitioning, along with small-scale spatial variability, within the guild of suspension feeders. We demonstrated that interspecific competition was limited among... |
Tipo: Text |
Palavras-chave: Trophic plasticity; Spatial variability; Stable isotopes; Sessile epibionts; Oysters; Shellfish. |
Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2626.pdf |
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Chouvelon, Tiphaine; Chappuis, A.; Bustamante, Paco; Lefebvre, Sebastien; Mornet, Francoise; Guillou, G.; Violamer, L.; Dupuy, Christine. |
European sardine (Sardina pilchardus) and European anchovy (Engraulis encrasicolus) are two species of economical and ecological significance in the Bay of Biscay (north-east Atlantic). However, the trophic ecology of both species is still poorly known in the area, and more generally, few studies have considered the potential trophic overlap between sardines and anchovies worldwide. This study aims to highlight the trophic links between the mesozooplankton and adults of these two pelagic fish in the Bay of Biscay, through carbon and nitrogen stable isotope analysis (SIA). Mesozooplankton and individuals of sardines and anchovies were collected during one season (spring 2010), over spatially contrasted stations within the study area. First, the potential... |
Tipo: Text |
Palavras-chave: Plankton preservation; Plankton delipidation; Pelagic fish; Trophic interactions; Spatial variability; Isotopic mixing model. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00176/28741/27280.pdf |
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Registros recuperados: 73 | |
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