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	Provedor de dados ArchiMer (1) Autor Chassagne, Claire (1) Mietta, Francesca (1) Verney, Romaric (1) Winterwerp, Johan C. (1) Palavra-chave Discretization into classes (1) Flocculation (1) Kaolinite (1) Natural mud (1) Population balance equation (1) Zeta-Potential (1) Mais... Tipo do documento Text (1) Ano 2011 (1) País France (1) Idioma Inglês (1)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 51 Primeira ... 1 2 3 ... Última PRECISION FARMING IN IRRIGATED CORN PRODUCTION: AN ECONOMIC PERSPECTIVE AgEcon Watson, Susan; Segarra, Eduardo; Machado, Stephen; Bynum, Edsel; Archer, Thomas; Bronson, Kevin. A dynamic optimization model is used to assess the profitability of precision and whole-field farming in corn production. Yield, on the average, was higher under whole-field farming practices, while net present value of returns was higher under precision farming, on the average, by 7.41% and 8.15%, respectively. Tipo: Conference Paper or Presentation Palavras-chave: Precision farming; Mathematical optimization; Technology adoption; Crop Production/Industries. Ano: 2003 URL: http://purl.umn.edu/35053 Precision Farming by Cotton Producers in Eleven Southern States: Results from the 2005 Southern Precision Farming Survey AgEcon Cochran, Rebecca L.; Roberts, Roland K.; English, Burton C.; Larson, James A.; Goodman, W. Robert; Larkin, Sherry L.; Marra, Michele C.; Martin, Steven W.; Paxton, Kenneth W.; Shurley, W. Donald; Reeves, Jeanne M.. Precision Farming by Cotton Producers in Eleven Southern States: Results from the 2005 Southern Precision Farming Survey Tipo: Report Palavras-chave: Cotton; Precision farming; Survey; Agribusiness; Farm Management; Production Economics; Research and Development/Tech Change/Emerging Technologies. Ano: 2006 URL: http://purl.umn.edu/91332 Economic Analysis of Phosphorus Applications under Variable and Single-Rate Applications in the Bothaville District AgEcon Maine, Ntsikane; Nell, Wilhelm T.; Lowenberg-DeBoer, James; Alemu, Zerihun Gudeta. Variable-rate (VR) application of inputs in South African cash crop production is mainly concerned with fertilizer and lime, and this indicates the importance of these inputs in cash crop production. However, the profitability of VR application of inputs has not yet been investigated under South African conditions. This paper studies the maize yield response to variable-rate application of phosphorus (P) and the profitability thereof in South Africa, on the basis of data collected on a 104-hectare experimental field on a farm in the Bothaville district. The strip-plot design of 180 strips was used for this on-farm research experiment. This design involved treatments that run in the same direction across the field as planting and harvesting. The objective... Tipo: Journal Article Palavras-chave: Precision agriculture; Precision farming; Site-specific phosphorus management; Variable-rate application; Fertilizer; Yield response; South Africa; Crop Production/Industries. Ano: 2007 URL: http://purl.umn.edu/7047 IMPROVING NITROGEN MANAGEMENT USING SITE-SPECIFIC TECHNOLOGY IN THE VIRGINIA COASTAL PLAIN AgEcon Peng, Wei; Bosch, Darrell J.. On a Virginia crop farm, alternative levels of information are evaluated for managing nitrogen applications based on soil properties and yield potential. Application of variable rates of nitrogen based on crop yield potential can increase profitability and reduce nitrogen pollution potential. Tipo: Conference Paper or Presentation Palavras-chave: Precision farming; Pollution; Cost; Information; Soil maps; Environmental Economics and Policy; Resource /Energy Economics and Policy. Ano: 2000 URL: http://purl.umn.edu/21746 RISK MANAGEMENT POTENTIAL OF PRECISION FARMING TECHNOLOGIES AgEcon Lowenberg-DeBoer, James. Initial ideas on risk management uses of precision agricultural technology focused on site-specific treatment of problem areas to reduce the probability of low yields and returns. Recent discussions deal with sensor and remote-sensing information to improve marketing and "as applied maps" as trace-back mechanisms to manage liability. A theoretical model is presented that suggests that there are plausible circumstances under which precision farming can reduce temporal yield variability. Empirical evidence from an on-farm trial of site-specific P&K management in the Eastern Cornbelt supports the hypothesis that precision farming can have risk-reducing benefits. Tipo: Journal Article Palavras-chave: Food safety; GIS; GPS; Crop insurance; Marketing; Precision farming; Site specific management; Risk; Research and Development/Tech Change/Emerging Technologies; Risk and Uncertainty. Ano: 1999 URL: http://purl.umn.edu/15366 Optical crop sensor for variable-rate nitrogen fertilization in corn: II - indices of fertilizer efficiency and corn yield Rev. Bras. Ciênc. Solo Bragagnolo,Jardes; Amado,Telmo Jorge Carneiro; Nicoloso,Rodrigo da Silveira; Santi,Antônio Luis; Fiorin,Jackson Ernani; Tabaldi,Fabiano. Generally, in tropical and subtropical agroecosystems, the efficiency of nitrogen (N) fertilization is low, inducing a temporal variability of crop yield, economic losses, and environmental impacts. Variable-rate N fertilization (VRF), based on optical spectrometry crop sensors, could increase the N use efficiency (NUE). The objective of this study was to evaluate the corn grain yield and N fertilization efficiency under VRF determined by an optical sensor in comparison to the traditional single-application N fertilization (TSF). With this purpose, three experiments with no-tillage corn were carried out in the 2008/09 and 2010/11 growing seasons on a Hapludox in South Brazil, in a completely randomized design, at three different sites that were analyzed... Tipo: Info:eu-repo/semantics/article Palavras-chave: Nitrogen; N-Sensor; Optical spectrometry; Precision farming. Ano: 2013 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832013000500019 Determination of nitrogen and chlorophyll levels in bean-plant leaves by using spectral vegetation bands and indices Rev. Ciênc. Agron. Abrahão,Selma Alves; Pinto,Francisco de Assis de Carvalho; Queiroz,Daniel Marçal de; Santos,Nerilson Terra; Carneiro,José Eustáquio de Souza. This study aimed to develop classifiers based on different combinations of spectral bands and vegetation indices from original, segmented and reflectance images in order to determine the levels of leaf nitrogen and chlorophyll in the bean, and to define the best time and best variables. A remote-sensing system was used, consisting of a helium balloon and two small-format digital cameras. Besides the individual spectral bands, four vegetation indices were tested: simple ratio, normalized difference, normalized difference in the green band, and modified-chlorophyll absorption. The classifiers proved to be efficient in determining levels of leaf nitrogen and chlorophyll. The best time for determining leaf N content was at 13 DAE (stage V4). The best... Tipo: Info:eu-repo/semantics/article Palavras-chave: Precision farming; Remote sensing; Nitrogen dosage. Ano: 2013 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902013000300007 Spatial distribution of the chemical properties of the soil and of soybean yield in the field Rev. Ciênc. Agron. Gazolla-Neto,Alexandre; Fernandes,Marciabela Correa; Vergara,Rafael de Oliveira; Gadotti,Gizele Ingrid; Villela,Francisco Amaral. ABSTRACT The aim of this study was to evaluate the spatial dependence between chemical properties of the soil and yield components in the soybean using precision farming techniques. Samples of the soil and plants were taken from georeferenced points to determine the chemical properties of the soil and the yield components. The results were submitted to Pearson correlation analysis, descriptive statistics and geostatistics. The coefficient of variation showed a wide range of distribution for the chemical attributes of the soil, with the highest indices being found for the levels of available phosphorus (102%) and potassium (72.65%). Soil pH and organic matter showed a coefficient of variation of 5.96 and 15.93% respectively. Semivariogram analysis of the... Tipo: Info:eu-repo/semantics/article Palavras-chave: Precision farming; Soil fertility; Spatial distribution; Seed yield. Ano: 2016 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902016000200325 Biometric characteristics and canopy reflectance association for early-stage sugarcane biomass prediction Scientia Agricola Rocha,Murillo Grespan da; Barros,Flávio Margarito Martins de; Oliveira,Stanley Robson de Medeiros; Amaral,Lucas Rios do. ABSTRACT: Knowing the spatial variability of sugarcane biomass in the early stages of development may help growers in their management decision-making. Proximal canopy sensing is a promising technology that can identify this variability but is limited to quantifying plant-specific parameters. In this study, we evaluated whether biometric variables integrated with canopy reflectance data can assist in the generation of models for early-stage sugarcane biomass prediction. To substantiate this assertion, four sugarcane-producing fields were measured with an active crop canopy sensor and 30 sampling plots were selected for manually quantifying chlorophyll content, plant height, stalk number and aboveground biomass. We determined that Random Forest and Multiple... Tipo: Info:eu-repo/semantics/article Palavras-chave: Random forest; Canopy sensor; Vegetation indices; Precision farming; Data mining. Ano: 2019 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162019001400274 Development of a smart machine-vision-based system to detect water stress in greenhouse tomato plants CIGR Journal LAK, MohammadBagher. Timely detection of water stress in agricultural crops is important. In this paper, a smart classification algorithm was developed to detect water stress in tomato plants that were grown in the greenhouse. During the growth period, thermal and visible light images were acquired from the canopy tops in two states: (1) plants in normal conditions; and (2) plants under water stress. Images were obtained using a camera that recorded simultaneous frames of thermal and visible (red, green, and blue (RGB)) features. Based on these features, 22 parameters were defined and applied to classify the image frames. In order to develop an efficient algorithm, principal component analysis (PCA) was applied to optimize the classifying of parameters. For normalizing the... Tipo: Info:eu-repo/semantics/article Palavras-chave: Image classification; MLPNN; Normalization; PCA; Precision farming. Ano: 2021 URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/6343 Design and evaluation of a yield monitoring system for combinable crops CIGR Journal Kargarpour, Hoda; Razavi, Jalil; Hemmat, Abbas; Salar, Mahmood Reza. The existence of spatial variability within fields can be beneficial if inputs for arable crop are given to the field according to locally determined requirements. While yield mapping has become an important part of precision farming strategies, the goal of this paper is to plot a yield map by the application of yield monitoring components. A yield monitoring system capable of providing sufficient reliable data to plot a yield map for small grain fields in central regions of Iran was developed. The system consisted of an impact flow sensor determining the mass flow of grain, the GPS receiver determining geographical position of the machine, two shaft encoders measuring the speed of the combine, an ultrasonic sensor measuring the actual cutting width, and a... Tipo: Info:eu-repo/semantics/article Palavras-chave: Wheat; Spatial variability; Yield map; Mass flow sensor; Precision farming. Ano: 2016 URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3608 Registros recuperados: 51 Primeira ... 1 2 3 ... Última

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