SABIIA - Sistema Aberto e Integrado de Informação em Agricultura (Sabiia)

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...

Technical evaluation of artificial ligthing systems for broiler houses

Palavras-chave: Accuracy indices; Optimization; Sampling grids; Spatial variability.

Ano: 2016

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162016000100114

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...

Physical attributes of a pasture soil in southeast Goiás determined by geostatistics

Palavras-chave: Artificial lighting; Spatial variability; Energy efficiency; Aviculture.

Ano: 2012

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162012000600002

Cardoso,Gabriel G. de G.; Wanderley,Rilley C.; Souza,Mara L. C..

ABSTRACT This study aimed to evaluate the spatial dependence of physical attributes in a soil cultivated with Brachiaria grass. A 12-m regular sampling grid was established within an area of 3.500 m2. Thirty-five soil samples were collected at 0-30 cm depth for particle density, bulk density, texture and total porosity analysis. These data were evaluated using statistical methods of indicator kriging and the GS+ software. The GS+ software was used to develop three-dimensional maps and evaluate semivariograms. The spatial dependence was evaluated using experimental semivariograms. The analyzed attributes indicated the occurrence of spatial dependence when fit to the exponential model. Areas with higher porosity occurred in the regions with lower bulk...

EFFECTS OF SIZE AND SAMPLING GRID ON THE QUALITY OF APPARENT SOIL ELECTRICAL CONDUCTIVITY MAPS

Palavras-chave: Spatial variability; Management system; Kriging.

Ano: 2016

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162016000100143

Oldoni,Henrique; Costa,Bruno R. S.; Rocha Junior,Romero C.; Rabello,Ladislau M.; Bassoi,Luís H..

ABSTRACT The apparent soil electrical conductivity (ECa) is an attribute commonly used for the characterization of the spatial variability of soil, but its determination by handheld sensors consumes considerable time and labor. The reduction in the number of sampling points allows minimize them but can result in increased uncertainty of interpolated maps. Thus, the goal of this study was to identify the best spacing and number of ECa measurements, to guarantee the quality of maps generated in three vineyards. The ECa values were obtained using a handheld sensor in different sampling grids. The data were submitted to descriptive statistical and geostatistical analyses. The relative deviation and Kappa coefficient of agreement were used to assess the...

Management zones definition using soil chemical and physical attributes in a soybean area

Palavras-chave: Spatial variability; Geostatistics; Agricultural instrumentation.

Ano: 2019

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162019000800001

Bazzi,Claudio L.; Souza,Eduardo G.; Uribe-Opazo,Miguel A.; Nóbrega,Lúcia H. P.; Rocha,Davi M..

Several equipments and methodologies have been developed to make available precision agriculture, especially considering the high cost of its implantation and sampling. An interesting possibility is to define management zones aim at dividing producing areas in smaller management zones that could be treated differently, serving as a source of recommendation and analysis. Thus, this trial used physical and chemical properties of soil and yield aiming at the generation of management zones in order to identify whether they can be used as recommendation and analysis. Management zones were generated by the Fuzzy C-Means algorithm and their evaluation was performed by calculating the reduction of variance and performing means tests. The division of the area into...

GAUSSIAN SPATIAL LINEAR MODEL OF SOYBEAN YIELD USING BOOTSTRAP METHODS

Palavras-chave: Precision agriculture; Spatial variability; Fuzzy clustering; Management zones; Autocorrelation; Cross-correlation.

Ano: 2013

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162013000500007

Dalposso,Gustavo H.; Uribe-Opazo,Miguel A.; Johann,Jerry A.; Galea,Manuel; Bastiani,Fernanda De.

ABSTRACT This study aims to quantify the uncertainties associated to the parameters of a Gaussian spatial linear model (GSLM) and the assumption of normality residuals in the modeling of the spatial dependence of the soybean yield as a function of soil chemical attributes. The spatial bootstrap methods were used to determine the point and interval estimators associated with the model parameters. Hypothesis tests were carried out on the significance of the model parameters and the quantile-quantile probability plot was elaborated to verify the data normality. The uncertainties associated to the parameters of the spatial dependence structure were quantified and the potassium content, phosphorus content and soil pH covariates were significant to explain the...

TRANSITION FROM SYSTEMATIC TO DIRECTED SOIL SAMPLING DESIGNS IN AN AREA MANAGED WITH PRECISION AGRICULTURE

Palavras-chave: Geostatistics; Spatial resampling; Spatial variability.

Ano: 2018

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000100110

Pias,Osmar H. de C.; Cherubin,Maurício R.; Santi,Antônio L.; Basso,Claudir J.; Bayer,Cimélio.

ABSTRACT In agricultural areas with a historical of systematic soil sampling, alternative methodologies such as directed sampling design based on management zones (MZ) have been proposed to reduce sampling costs. The aim of this study was to evaluate the technical and economic impacts of replacing a dense systematic soil sampling design (cell size of 0.5 ha) by a systematic sampling with a smaller number of samples (cell size ranging from 1 to 4.5 ha), directed or conventional sampling design on the mapping of soil plant-available phosphorus (P), exchangeable potassium (K), and pHwater. The study was carried out in an agricultural area of 120 ha with soil classified as an Oxisol. The directed sampling designs were based on MZ delimited from data of...

RELATIONSHIP BETWEEN SAMPLE DESIGN AND GEOMETRIC ANISOTROPY IN THE PREPARATION OF THEMATIC MAPS OF CHEMICAL SOIL ATTRIBUTES

Palavras-chave: Sampling costs; Sampling grids; Spatial variability; Management zones.

Ano: 2019

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162019000300400

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...

SENSOR SYSTEMS FOR MAPPING SOIL FERTILITY ATTRIBUTES: CHALLENGES, ADVANCES, AND PERSPECTIVES IN BRAZILIAN TROPICAL SOILS

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

Molin,José Paulo; Tavares,Tiago Rodrigues.

ABSTRACT Soil fertility attributes have different scales and forms of spatial and temporal variations in agricultural fields. Adequate spatiotemporal characterization of these attributes is fundamental to the successful development of strategies for variable rate application of fertilizers, enabling the classic benefits of precision agriculture (PA). Studies on Brazilian soil have shown that at least 1 sample ha-1 is required for the reliable mapping of key fertility attributes. However, this sampling density is difficult owing to the operational challenges of sample collection and the cost of laboratory analyses. Given this limitation, soil sensors have emerged as a practical and complementary technique for obtaining information on soil attributes, at...

MODELING OF PHOSPHORUS LOSSES BY WATER EROSION

Palavras-chave: Spatial variability; Spectroscopy; On-the-go sensing; Hybrid laboratory.

Ano: 2019

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162019000800126

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...

Management zones in agriculture acording to the soil and landscape variables

Palavras-chave: WEPP model; Enrichment rate; Spatial variability.

Ano: 2018

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000100149

Delalibera,Hevandro C.; Weirich Neto,Pedro H.; Nagata,Noemi.

The study of spatial variability of soil and plants attributes, or precision agriculture, a technique that aims the rational use of natural resources, is expanding commercially in Brazil. Nevertheless, there is a lack of mathematical analysis that supports the correlation of these independent variables and their interactions with the productivity, identifying scientific standards technologically applicable. The aim of this study was to identify patterns of soil variability according to the eleven physical and seven chemical indicators in an agricultural area. It was used two multivariate techniques: the hierarchical cluster analysis (HCA) and the principal component analysis (PCA). According to the HCA, the area was divided into five management zones: zone...

BED TEMPERATURE IN COMPOST BARNS TURNED WITH ROTARY HOE AND OFFSET DISC HARROW

Palavras-chave: Multivariate analysis; Precision agriculture; Spatial variability.

Ano: 2012

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162012000600021

Mota,Vania C.; Andrade,Ednilton T. de; Leite,Daniel F..

ABSTRACT The success of confinement for dairy cattle in the compost barn model depends mainly on the management of the bed and consists of its turning. This paper characterises the spatial variability of the bed temperature in the compost barn confinement model, as well as verifying whether there was an effect on efficiency from turning the bed with different agricultural implements. The experiment was conducted during the summer and winter of 2016, with 8 days of collection in each period. Data were analysed with descriptive statistics methods and geostatistical modelling with semivariograms and kriging maps. The results of the t-test at a5% significance level indicated that, after turning the bed with the plough or rotary hoe, the temperature values were...

SOIL ATTRIBUTES AND WHEAT PERFORMANCE IN A GEOREFERENCED SEED PRODUCTION FIELD

Palavras-chave: Aeration/oxygenation of the bed; Dairy cattle; Confinement; Agricultural implements; Spatial variability.

Ano: 2019

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162019000300280

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....

Aplicação da geoestatística na análise da fertilidade do solo em propriedade familiar do Circuito das Frutas do Estado de São Paulo.

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

Infoteca-e

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

Determination of diet in Manila clams by spatial analysis of stable isotopes

SST spatial anisotropic covariances from METOP-AVHRR data

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

Small-scale spatial variability of food partitioning between cultivated oysters and associated suspension-feeding species, as revealed by stable isotopes

Tandeo, Pierre; Autret, Emmanuelle; Chapron, Bertrand; Fablet, Ronan; Garello, Rene.

The Advanced Very High Resolution Radiometer (AVHRR) instrument on-board the METOP satellite is designed to provide very accurate measurements of Sea Surface Temperature (SST). In this work, using one year of METOP-AVHRR data and a geostatistical approach, we characterize the spatial anisotropy and non-stationarity of the SST variability using oriented ellipsoids. The method is also able to separate the true SST variability from the artificial error introduced by the METOP-AVHRR sensor. These spatial parameters are then used for producing variability atlases (available on-line) over the whole ocean.

Tipo: Text

Palavras-chave: SST; METOP-AVHRR; Spatial variability; Anisotropy.

Ano: 2014

URL: http://archimer.ifremer.fr/doc/00165/27586/25818.pdf

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

Tidally-induced shear stress variability above intertidal mudflats in the macrotidal Seine estuary

Trophic ecology of European sardine Sardina pilchardus and European anchovy Engraulis encrasicolus in the Bay of Biscay (north-east Atlantic) inferred from delta C-13 and delta N-15 values of fish and identified mesozooplanktonic organisms

Verney, Romaric; Brun Cottan, J; Lafite, R; Deloffre, J; Taylor, J.

Tidal currents and the spatial variability of tidally-induced shear stress were studied during a tidal cycle on four intertidal mudflats from the fluvial to the marine part of the Seine estuary. Measurements were carried out during low water discharge (< 400 m(3) s(-1)) in neap and spring tide conditions. Turbulent kinetic energy, covariance, and logarithmic profile methods were used and compared for the determination of shear stress. The c(TKE) coefficient value of 0.19 cited in the literature was confirmed. Shear stress values were shown to decrease above mudflats from the mouth to the fluivial part of the estuary due to dissipation of the tidal energy, from 1 to 0.2 N m-(2) for spring tides and 0.8 to 0.05 N m(-2) for neap tides. Flood currents...

Tipo: Text

Palavras-chave: Seine estuary (France); Spatial variability; Neap spring conditions; Intertidal mudflat; Shear stress; Tidal currents.

Ano: 2006

URL: http://archimer.ifremer.fr/doc/2006/publication-1887.pdf

Experimental Design Efficiency and Test Ability on Erva-mate Genetic Improvement

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

PFB - Pesquisa Florestal Brasileira

Sturion, José Alfredo; Resende, Marcos Deon Vilela de.

The perennial plant selection is based on individual genetic values predicted from phenotypic observations. The more adequate the control of environmental variability, the more accurate the prediction. This paper aimed to investigate: 1) the test ability by using the significance of Snedecor F test for block effects; 2) the spatial variability within blocks by using the plot intraclass correlation coefficient; 3) the experimental design efficiency in terms of the local control, by using the significance of Snedecor F test for block effects and the plot intraclass correlation coefficient (c2), simultaneously; 4) the genotype x environmental interaction within site, by using the genetic correlation coefficient across replications. The used data...