oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

4 ( 1 )

2019 ( 283 )

2018 ( 568 )

2017 ( 604 )

Custom range...

Search Results: 1 - 10 of 366412 matches for " Eduardo G. de;Uribe-Opazo "
All listed articles are free for downloading (OA Articles)
Page 1 /366412
Display every page Item
Determination of management zones from normalized and standardized equivalent produtivity maps in the soybean culture
Suszek, Grazieli;Souza, Eduardo G. de;Uribe-Opazo, Miguel A.;Nobrega, Lucia H. P.;
Engenharia Agrícola , 2011, DOI: 10.1590/S0100-69162011000500007
Abstract: through the site-specific management, the precision agriculture brings new techniques for the agricultural sector, as well as a larger detailing of the used methods and increase of the global efficiency of the system. the objective of this work was to analyze two techniques for definition of management zones using soybean yield maps, in a productive area handled with localized fertilization and other with conventional fertilization. the sampling area has 1.74 ha, with 128 plots with site-specific fertilization and 128 plots with conventional fertilization. the productivity data were normalized by two techniques (normalized and standardized equivalent productivity), being later classified in management zones. it can be concluded that the two methods of management zones definition had revealed to be efficient, presenting similarities in the data disposal. due to the fact that the equivalent standardized productivity uses standard score, it contemplates a better statistics justification.
Software para estimativa do custo operacional de máquinas agrícolas - MAQCONTROL
Piacentini, Liane;Souza, Eduardo G. de;Uribe-Opazo, Miguel A.;Nóbrega, Lúcia H. P.;Milan, Marcos;
Engenharia Agrícola , 2012, DOI: 10.1590/S0100-69162012000300020
Abstract: the rational mechanization has as main objectives the selection and optimization of mechanized systems. an adequate purchase of agricultural machinery is not sufficient if its use is not controlled in operational and financial aspects. this work describes the development of software to estimate operational costs of agricultural machinery (maqcontrol), using borland delphi's development environment and firebird database. the operational costs were divided in fixed and variable. in fixed costs, the expenses with depreciation, interest, storage and insurance were estimated. in variable costs, the emphasis was given to the expenses on maintenance, lubricating oils, filters, tires, grease, fuel, small repairs, and parts replacement. results have shown the software efficiency for the proposed objectives. therefore, the maqcontrol software proved to be an important tool in the rural management process, because it reduces information costs and accelerate the precise determination of operational costs of farm machinery.
PRAPRAG: software para planejamento racional de máquinas agrícolas
Mercante, Erivelto;Souza, Eduardo G. de;Johann, Jerry A;Gabriel Filho, Antonio;Uribe-Opazo, Miguel A;
Engenharia Agrícola , 2010, DOI: 10.1590/S0100-69162010000200015
Abstract: the software praprag is a tool used for choosing agricultural machines and implements that present the lowest cost per area or produced amount, as well as, to it makes the machines acquisition planning for the agricultural property, from both technical and economical points of view. it was used the programming language borland delphi 3.0. from the machine and implement handouts, it was created a database where the user can register and modify their characteristics of use. the software showed to be a useful and friendly tool. the software provides high speed, safety and reliability for the productive and economical process of the properties, at the selection and acquisition of agricultural systems, as well as for the determination of costs with the used labor.
Influência da dire??o de semeadura do milho nas variáveis reflectancia e índice de vegeta??o verde normalizado
Souza, Eduardo G. de;Orlando, Gracielle A.;Uribe-Opazo, Miguel A.;Silva, Edson A. da;Scharf, Peter;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2004, DOI: 10.1590/S1415-43662004000100012
Abstract: the objective of this work was to study the influence of the row direction of corn (zea mays) on its spectral properties measured in the field, including the green normalized difference vegetation index (green ndvi). spectral properties of corn are known to be related to the nitrogen (n) status of the corn and may form the basis for real-time site-specific rates of n application. row direction effects on spectral properties may be substantial before canopy closure. if so, it will be necessary to account for these effects in order to accurately predict the n need of corn from spectral measurements. corn was planted directly, with no tillage, in north-south (ns) and east-west (ew) oriented rows. nitrogen was applied as ammonium nitrate at a rate of 160 kg n ha-1. reflectance was measured with spectral radiometers placed 30 cm above individual plants. reflectance and green ndvi were bly dependent on time of day for corn in ns rows, and much less so for corn in ew rows. reflectance and green ndvi were lower for corn in ew rows than corn in ns rows, but lack of replication makes it difficult to be certain that this was due to row direction. green ndvi was less sensitive than reflectance to row direction and therefore may be more appropriate for use in a real-time variable-rate nitrogen application system.
Model to estimate the sampling density for establishment of yield mapping
Spezia, Graciele R.;Souza, Eduardo G. de;Nóbrega, Lúcia H. P.;Uribe-Opazo, Miguel A.;Milan, Marcos;Bazzi, Claudio L.;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2012, DOI: 10.1590/S1415-43662012000400016
Abstract: yield mapping represents the spatial variability concerning the features of a productive area and allows intervening on the next year production, for example, on a site-specific input application. the trial aimed at verifying the influence of a sampling density and the type of interpolator on yield mapping precision to be produced by a manual sampling of grains. this solution is usually adopted when a combine with yield monitor can not be used. an yield map was developed using data obtained from a combine equipped with yield monitor during corn harvesting. from this map, 84 sample grids were established and through three interpolators: inverse of square distance, inverse of distance and ordinary kriging, 252 yield maps were created. then they were compared with the original one using the coefficient of relative deviation (crd) and the kappa index. the loss regarding yield mapping information increased as the sampling density decreased. besides, it was also dependent on the interpolation method used. a multiple regression model was adjusted to the variable crd, according to the following variables: spatial variability index and sampling density. this model aimed at aiding the farmer to define the sampling density, thus, allowing to obtain the manual yield mapping, during eventual problems in the yield monitor.
Anisotropia no estudo da variabilidade espacial de algumas variáveis químicas do solo
Guedes, Luciana Pagliosa Carvalho;Uribe-Opazo, Miguel Angel;Johann, Jerry Adriany;Souza, Eduardo Godoy de;
Revista Brasileira de Ciência do Solo , 2008, DOI: 10.1590/S0100-06832008000600001
Abstract: studies on soil fertility mapping based on geostatistics should consider some spatial variability characteristics such as spatial continuity and absence of anisotropy. the present study reports an anisotropic analysis of the spatial variability of the following soil chemical variables: iron (fe), potential acidity (h + al), organic matter (om) and manganese (mn) of a data set of 128 plots without local chemical management, spatially referenced, studied between 1998 and 2002 in a dystrophic red latosol (oxisol), in cascavel, paraná, brazil. anisotropy was identified through the construction of directional semivariograms with adjusted models and corrected through linear transformations and by combined models. thereafter a model was used adjusted to the omnidirectional semivariogram for the construction of thematic variability maps of the studied variables. the existence of geometric anisotropy was observed for the variable h + al. the variables mo, mn and fe evidenced the presence of combined anisotropy. the geometric anisotropy was first corrected and then the zonal anisotropy was adjusted. based on anisotropy it was possible to eliminate the biased directions, enhancing the semivariogram fitting and precision of the thematic maps of chemical variables.
Influência da densidade amostral e do tipo de interpolador na elabora o de mapas temáticos = The influence of sample density and interpolation type on the elaboration of thematic maps
Edy Célia Coelho,Eduardo Godoy de Souza,Miguel Angel Uribe-Opazo,Raimundo Pinheiro Neto
Acta Scientiarum : Agronomy , 2009,
Abstract: O objetivo deste trabalho foi avaliar a influência da densidade amostral (três grades) e do tipo de interpolador (krigagem, inverso da distancia, inverso da distancia ao quadrado e polinomial) na elabora o de mapas temáticos da produtividade da soja em umaárea de LATOSSOLO VERMELHO Distroférrico, no período de 1998 a 2002, conduzida em sistema de agricultura de precis o. As grades selecionadas possuíam 128, 64 e 32 parcelas utilizando amostragem alinhada sistemática estratificada (AASE). A partir de cada gradeamostral e utilizando cada um dos interpoladores, foram gerados os mapas temáticos. O coeficiente de desvio relativo (CDR) foi proposto visando expressar a diferen a média em módulo dos valores interpolados em cada grade em rela o à grade considerada comoreferência, ou seja, a amostragem alinhada sistemática estratificada, com 128 parcelas, e interpola o por krigagem (AASE 128 Krigagem). O CDR mostrou-se eficiente na compara o de mapas e possibilitou concluir que, para utilizar todo o potencial da krigageme esse método ser recomendado, é necessário ter muitos pontos para que um bom semivariograma seja construído. Caso contrário, podem-se usar os outros interpoladores analisados. O método amostragem alinhada sistemática estratificada 128 inverso da distanciafoi o que mais se aproximou do método assumido como referência, AASE 128 Krigagem. The objective of this work was to evaluate the influence of the sampling density (three grids) and of the type of interpolation (kriging, inverse of the distance, inverse of the square distance, and polynomial) in the elaboration of thematic maps of soybean yield in an area of Dystroferric Red Nitosol under precision agriculturefrom 1998 to 2002. The selected grids had 128, 64 and 32 units using stratified systematic aligned sampling (SSAS). The thematic maps was generated from each sampling grid and using each of the interpolators. The relative deviation coefficient (CDR) was proposed to express the average difference in module of the values interpolated in each grid in relation to the considered standard SSAS grid with 128 units and kriging interpolator. The CDR proved efficient in the comparison of maps and made it possible to conclude that to effectively use the entire potential of the kriging, it is necessary to have several points, so that a good semivariogram is constructed. Otherwise, any of the other analyzed interpolators can be used. The SSAS 128 inverse distance method was most similar to thereference, SSAS 128 Kriging.
Unidades de manejo a partir de dados de produtividade = Determination of management zones using yield data.
Lairton Milani,Eduardo Godoy de Souza,Miguel Angel Uribe-Opazo,Antonio Gabriel Filho
Acta Scientiarum : Agronomy , 2006,
Abstract: A agricultura de precis o é um conjunto de tecnologias que visa o aumento da eficiência com base no manejo diferenciado de áreas agrícolas. Neste contexto, é importante estabelecer metodologias nos quais informa es de produtividade, solo ou indicadores compostos possam ser utilizados para a determina o de unidades de manejo. O objetivo deste trabalho foi desenvolver uma metodologia para defini o de unidades de manejo em fun o de mapas de produtividade de cinco safras agrícolas. Foi medida a produtividade da cultura soja, durante os anos de 1998 a 2002, de uma área localizada no município de Cascavel, Estado do Paraná, e utilizando técnicas de geoestatística foram gerados mapas de produtividade. A área amostrada possui 1,74 ha, sendo constituída de 256 parcelas, 128 com manejo químico localizado e 128 sem manejo químico localizado. Na colheita, utilizou-se uma colhedora de parcelas e verificou-se dependência espacial para os sistemas de cultivo, em todos os anos. Os valores pontuais de produtividade de soja de cada ano foram padronizadosutilizando-se a técnica denominada escore padr o, em seguida reclassificados em baixo, médio e alto, o que possibilitou a compara o das produtividades de diferentes anos e a gera o de um mapa de produtividade média. Com a produtividade padronizada e ocoeficiente de varia o classificados em baixo, médio e alto foi gerado um mapa com as unidades de manejo. A metodologia mostrou-se eficiente para identificar regi es homogêneas. Precision agriculture is a set of technologies that aims the efficiency increase based on the differentiated management of agricultural areas. In this context, it is important to establish methodologies to use the yield information, soil or indicators in the determination of management zones. The aim of this paper was to develop a methodology for the definition of management zones according to yield maps of five growing seasons. The soybean yield was measured from 1998 to 2002, in an area in Cascavel, Paraná State, Brazil. Yield maps were generated using geostatic techniques. The sampled area has 1.74 ha with 256 plots: 128 with site- specificchemical management and 128 without site-specific chemical management. A plot combine was used for harvest. In the experiment the spatial dependence was verified for both planting systems in each year. The punctual values of soybean yield of each year were standardized using the standard score technique. After that, these values were reclassified in low, medium and high, allowing the comparison of productivities in different years and the generation of a y
Determina o e remo o do tempo de atraso etermina o em mapas de colheita de milho = Determination and removal of the time delay in corn crop maps
Ricardo Michelan,Eduardo Godoy de Souza,Miguel Angel Uribe-Opazo
Acta Scientiarum : Agronomy , 2007,
Abstract: Devido a grande quantidade de informa es coletadas a baixo custo, omapeamento da produtividade do campo tem sido a chave do desenvolvimento para a agricultura de precis o. Entretanto, nesse processo podem ocorrer erros, sendo o principal deles o tempo de atraso, descrito como o tempo dispendido entre o corte da planta pelabarra da plataforma e a passagem do gr o pelo sensor de produtividade e a correla o deste fluxo com a correta posi o da colhedora quando a cultura foi ceifada. A análise de dependência espacial pelo método do melhor ajuste do semivariograma e dos seus parametros foi o que determinou o melhor tempo de atraso. A variancia do efeito pepitamede a quantidade de varia o de pequena escala em um conjunto de dados espaciais. Podese supor uma dependência entre o efeito pepita e o tempo de atraso, dessa forma, varia o do efeito pepita deve ser minimizada com o verdadeiro tempo de atraso. Para esta análise pelo semivariograma, os dados de produtividade úmida, umidade e eleva o foram divididos em 12 sub-áreas e cada uma teve o tempo de atraso determinado, variando de 3 a 27 segundos para produtividade úmida e umidade e de 0 a 3 segundos para eleva o. O método de determina o dos tempos de atraso pelo melhor ajuste do semivariograma foi satisfatório, apesar das condi es atípicas, ou seja, alta variabilidade natural dos dados para os três fatores, provando as mudan as do tempo de atraso em uma área relativamente pequena. Due to the great amount of information collected at a low cost, the harvest mapping has been the development key for Precision Agriculture. However, mistakes can happen in this process. The main of them, the time delay, is described as the time spent among the cut of the plant by the bar of the platform and the passage of the grain for the sensor of productivity, and the correlation of this flow with the correct position of the combine when the culture was harvested. The spatial dependence analysis by the best adjustment semivariogram method and their parameters determined the best time delay. The variance of nugget effect measures the small amount variation in a group of space data. Dependence between the nugget effect and the time delay can be supposed. Thus, the variation of the nugget effect should be minimized with the true time delay. For the semivariogramanalysis, the data of moisture productivity, moisture and elevation were divided in 12 subareas and each area had the determined time delay, varying from 3 to 27 second for moisture productivity and moisture and from 0 to 3 seconds for elevation. The best adjustment se
índices de vegeta??o no milho em fun??o da hora do dia e da taxa de nitrogênio aplicada
Souza, Eduardo G.;Rocha, Teoferson;Uribe-Opazo, Miguel A.;Nóbrega, Lúcia H. P.;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2009, DOI: 10.1590/S1415-43662009000700008
Abstract: methods have been proposed seeking to improve the application of nitrogen (n) simultaneously with yield increase and environmental protection, reducing the nitrate concentration in the soil and in the water. one of these methods, precision agriculture consists of the site-specific application of the agricultural inputs as a function of the local need. in this context, the measurement of the spectral leaf reflectance shows itseif as a promising method for the instantaneous remote sensing of deficiency of n in corn through the calculations of vegetation indexes. however, the characteristics of the interaction of the plants with the solar radiation are not well known. this work evaluated the behavior of the vegetation indexes in relation to the hour of the day and the applied nitrogen rate. six different indexes were studied: relationship near-infrared/red (nir/red), relationship near-infrared/green (nir/green), normalized difference vegetation index (ndvi), green normalized difference vegetation index (gndvi), soil adjusted vegetation index (savi) and optimized soil adjusted vegetation index (osavi). when only the data collected around the half solar day weve analized, the indexes that presented the lowest dispersion results were ndvi and osavi. for data collected during the whole day the indexes that presented better explanation of the variability were savi and osavi.
Page 1 /366412
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.