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| Registros recuperados: 144 | |
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| Antuniassi,Ulisses R.; Miller,Paul; Paice,Mark. |
| A method for measuring the performance of agricultural injection metering systems was developed and used to assess the characteristics of three commercial system designs. Steady-state characteristics were measured using both colored dyes and salt as tracers. Dynamic response characteristics were determined by measuring salt concentration downstream of the injection point by monitoring electrical conductivity of the spray solution. Salt added to a viscous test liquid changed viscosity slightly only at low shear rates and it is concluded that this liquid is appropriate for use in evaluation tests with injection systems. Results from tests with 2 systems specifically designed for operation with agricultural sprayers gave a linear response with both water and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Precision agriculture; Sprayers; Pesticides. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662002000100028 |
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| Bottega,Eduardo L.; Pegoraro,Camilo; Guerra,Naiara; Oliveira Neto,Antonio M. de; Queiroz,Daniel M. de. |
| ABSTRACT Brazil is one of the largest grain producers in the world, due to its extensive arable land and favorable climate for the cultivation of any species. The production could be higher, but problems such as competition between crops and weeds reduces crop yields. This study aimed to analyze the spatial distribution of weeds, especially milkweed (Sonchus oleraceus), horse weed (Conyza spp.) and ‘maria-mole’ (Senecio brasiliensis) in an area under no-tillage system for two harvests. The work was carried out during the 2013/14 and 2014/15 crop years in an area of 22.5 ha, where soybean is grown in the summer and oat in the winter. The weeds were mapped using a sampling grid of 85 points. The number of plants present in 0.25 m2 was recorded at each... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Precision agriculture; Spatial variability; Sonchus oleraceus; Conyza spp.; Senecio brasiliensis. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662016001201107 |
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| Santos,Railton O. dos; Franco,Laís B.; Silva,Samuel A.; Sodré,George A.; Menezes,Agna A.. |
| ABSTRACT The knowledge on the spatial variability of soil properties and crops is important for decision-making on agricultural management. The objective of this study was to evaluate the spatial variability of soil fertility and its relation with cocoa yield. The study was conducted over 14 months in an area cultivated with cocoa. A sampling grid was created to study soil chemical properties and cocoa yield (stratified in season, off-season and annual). The data were analyzed using descriptive and exploratory statistics, and geostatistics. The chemical attributes were classified using fuzzy logic to generate a soil fertility map, which was correlated with maps of crop yield. The soil of the area, except for the western region, showed possibilities ranging... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Precision agriculture; Cocoa; Spatial variability; Fuzzy logic. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017000200088 |
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| Santos,Adão F. dos; Silva,Rouverson P. da; Tavares,Tiago O.; Ormond,Antonio T. S.; Rosalen,David L.; Assis,Leonardo C. de. |
| ABSTRACT GNSS positioning errors are certain, regardless of the adopted positioning method. In agriculture, these errors may represent higher or lower overlapping rates between passes of a mechanical assembly, affecting operation quality. Therefore, this study evaluated the main errors arising from peanut sowing operation performed with an auto-steer guidance system by an RTX signal, using the Statistical Process Control techniques. The errors evaluated were: in tractor lateral displacement, project execution, and parallelism between passes of tractor-seeder set. The average errors of project execution in all passes were within the range specified by the manufacturer, i.e. lower than 3.8 cm. The average error of tractor-seeder set was also within the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Autopilot; Precision agriculture; Electric auto-steering; RTX; GNSS. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017001000731 |
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| Bottega,Eduardo L.; Queiroz,Daniel M. de; Pinto,Francisco A. C.; Oliveira Neto,Antonio M. de; Vilar,Cesar C.; Souza,Cristiano M. A. de. |
| The objective of this study was to evaluate the influence of different sampling grids density in the lime requirements in an Oxisol. The experiment was conducted at a rural property located in Sidrolândia city, Mato Grosso do Sul state, in the Brazilian ‘Cerrado’. In the soil attributes mapping, regular sampling grid was used consisting of 99 points, spread over an area of 90 ha. Other two grids (51 and 27 points) were derived by deleting lines or lines and points from the original one. Based on the results of soil analysis, the lime requirement at each sample point was calculated. Using geostatistical techniques the spatial variability of lime requirement was studied and grid configuration for each sample was tested. By kriging, maps were made. By... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Precision agriculture; Geostatistics; Spatial variability; Soil acidity correction. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662014001100008 |
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| Carpes,Dauto P.; Alonço,Airton dos S.; Rossato,Fernando P.; Veit,André A.; Souza,Lucas B. de; Francetto,Tiago R.. |
| ABSTRACT The correct longitudinal distribution of seeds by the seeder machine is one of the features that most contributes to obtain an adequate plant stand and good crop yield. The objective of this study was to evaluate the longitudinal distribution of corn seeds by seed conductor tube types, combined with a horizontal perforated disc and a pneumatic meter, altering the seeding density rate. The experiment was conducted in a laboratory using a seed meter test bench. Treatments were a combination of two seed meters, six conductor tubes and four peripheral speeds for the meter disc, corresponding to densities of 60, 70, 80 and 90 thousand corn seeds per hectare and were organized in a three-factor scheme with four repetitions. By increasing the seeding... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Agricultural mechanization; Precision seeding; Precision agriculture; Row crop planter; Seed metering. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017000900657 |
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| Spezia,Graciele R.; Souza,Eduardo G. de; Nóbrega,Lúcia H. P.; Uribe-Opazo,Miguel A.; Milan,Marcos; Bazzi,Claudio L.. |
| 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... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Precision agriculture; Thematic map; Spatial variability. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662012000400016 |
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| Barros,Murilo M. de; Volpato,Carlos E. S.; Silva,Fabio M. da; Conceição,Fagner G. da; Corrêa Júnior,Delorme; Ribeiro,Luiz F.. |
| ABSTRACT The objective of this study was to evaluate the performance of a variable-rate fertilizer distribution system for coffee crop, simultaneously applying two products. Two types of tests were performed: transversal deposition and longitudinal deposition. The transversal deposition test, with tarps, aimed to quantify the variations between programmed and applied doses, using a completely randomized design (CRD), in a factorial scheme, and the Scott-Knott test at p < 0.05. The longitudinal deposition test aimed to determine the distribution characteristics of the equipment along the displacement line, based on relative frequency values. In addition, the application rates on both sides of the distribution system were analysed using a CRD and the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Coffee production; Precision agriculture; Application at variable doses. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662016000200188 |
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| Souza,Zigomar M. de; Cerri,Domingos G. P.; Magalhães,Paulo S. G.; Siqueira,Diego S.. |
| Soils submitted to the same management system in places with little variation of landscape, manifest differentiated spatial variability of their attributes and crop yield. The aim of this work was to investigate the correlation between spatial variability of the soil attributes and sugarcane yield as a result of soil topography. To achieve this objective, a test area of 42 ha located at the São João Sugar Mill, in Araras, in the State of São Paulo, Brazil, was selected. Sugarcane yield was measured with a yield monitor fitted in a sugarcane harvester and GPS signal. A total of 170 soil samples were taken at regular 50 m grid, at a depth of 0 - 0.2 m. The area under study was divided into two sites based on topography. The following soil attributes were... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Saccharum sp; Geostatistics; Semivariogram; Curvature; Precision agriculture. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662010001200001 |
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| Jacintho,João L.; Ferraz,Gabriel A. e S.; Silva,Fabio M. da; Santos,Sthéfany A.. |
| ABSTRACT This study aimed to apply precision agriculture techniques in coffee production, using correlation analysis in the definition of management zones. This work was carried out in a 22-ha area of coffee (Coffea arabica L.), cv. ‘Topázio MG 1190’, which was sampled on a regular grid, using a topographic GPS, totaling 64 georeferenced samples (on average, 2.9 points per ha). Descriptive analysis was used in the data, followed by Pearson’s correlation analysis at 0.05 significance between soil chemical attributes, agronomic characteristics of the plants and altitude. It was possible to verify the correlation of soil chemical attributes, agronomic characteristics of the plants and altitude with coffee yield. Altitude was the variable most correlated with... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Coffea arabica L.; Precision agriculture; Yield; Thematic mapping. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017000200094 |
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| Carvalho,Luis C. C.; Silva,Fabio M. da; Ferraz,Gabriel A. e S.; Stracieri,Juliana; Ferraz,Patrícia F. P.; Ambrosano,Lucas. |
| ABSTRACT To make the coffee activity competitive, some farmers use precision coffee farming. Thus, it is possible to create thematic maps that guide management practices for regions where there are limitation for the plant development. The objective of this study was to identify the spatial dependence of coffee crop yield, in 2012 and 2013. The experimental area is located in a Haplustox in Três Pontas, Minas Gerais. One hundred sampling points were georeferenced for the collection of yield data through manual harvest. The difference of yield between crop seasons was also evaluated. Data were processed using geostatistical analysis. It was possible to identify and characterize the spatial dependence of all variables, as well as to create contour maps.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Coffea arabica L.; Spatial variability; Biennuality; Maps; Precision agriculture. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017000600410 |
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| Mondo,Vitor Henrique Vaz; Gomes Junior,Francisco Guilhien; Pinto,Taís Leite Ferreira; Marchi,José Luis de; Motomiya,Anamari Viegas de Araújo; Molin,José Paulo; Cicero,Silvio Moure. |
| The correlation of soil fertility x seed physiological potential is very important in the area of seed technology but results published with that theme are contradictory. For this reason, this study to evaluate the correlations between soil chemical properties and physiological potential of soybean seeds. On georeferenced points, both soil and seeds were sampled for analysis of soil fertility and seed physiological potential. Data were assessed by the following analyses: descriptive statistics; Pearson's linear correlation; and geostatistics. The adjusted parameters of the semivariograms were used to produce maps of spatial distribution for each variable. Organic matter content, Mn and Cu showed significant effects on seed germination. Most variables... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Glycine max; Precision agriculture; Seed quality. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-31222012000200002 |
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| Medeiros,Wilker Nunes; Valente,Domingos Sárvio Magalhães; Queiroz,Daniel Marçal de; Pinto,Francisco de Assis de Carvalho; Assis,Igor Rodrigues de. |
| ABSTRACT Mapping the apparent soil electrical conductivity (ECa) has become important for the characterization of the soil variability in precision agriculture systems. Could the ECa be used to locate the soil sampling points for mapping the chemical and physical soil attributes? The objective of this work was to examine the relations between ECa and soil attributes in two fields presenting different soil textures. In each field, 50 sampling points were chosen using a path that presented a high variability of ECa obtained from a preliminary ECa map. At each sampling point, the ECa was measured in soil depths of 0-20, 0-40 and 0-60 cm. In addition, at each point, soil samples were collected for the determination of physical and chemical attributes in the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Precision agriculture; Management zones; Soil sampling. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902018000100043 |
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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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| Molin,José Paulo; Castro,Cesar Nunes de. |
| The design of site-specific management zones that can successfully define uniform regions of soil fertility attributes that are of importance to crop growth is one of the most challenging steps in precision agriculture. One important method of so proceeding is based solely on crop yield stability using information from yield maps; however, it is possible to accomplish this using soil information. In this study the soil was sampled for electrical conductivity and eleven other soil properties, aiming to define uniform site-specific management zones in relation to these variables. Principal component analysis was used to group variables and fuzzy logic classification was used for clustering the transformed variables. The importance of electrical conductivity... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Precision agriculture; Soil physical properties; Fuzziness. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162008000600001 |
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| Registros recuperados: 144 | |
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