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| Registros recuperados: 144 | |
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| San Juan Martínez, Erwin. |
| El diagnóstico oportuno del estado nutrimental de los cultivos en la agricultura de precisión es de suma importancia y vitalidad; por lo que cada vez se hacen más necesarias técnicas que permitan conocer el estado nutrimental del cultivo de forma rápida, precisa y confiable. Es por ello que el presente trabajo tuvo como objetivo determinar la concentración de nitrógeno foliar en chile de agua mediante reflectancia, dicha característica se obtuvo por medio de equipos como: radiómetro (CROPSCAN), escáner de escritorio y cámara fotográfica digital, de igual forma se determinó un índice de verdor utilizando el medidor portátil SPAD Minolta 502 y, la concentración de nitrógeno foliar por el método Kjeldahl. A partir de esas mediciones y con el programa Curve... |
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Palavras-chave: Agricultura de precisión; Firmas espectrales; Nutriente; Precision agriculture; Spectral signatures; Nitrogen content; Edafología; Maestría. |
| Ano: 2014 |
URL: http://hdl.handle.net/10521/2285 |
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| Oliveira,Job T. de; Oliveira,Rubens A. de; Cunha,Fernando F. da; Santos,Eduardo S. dos. |
| ABSTRACT Studies that seek to identify a smaller number of soil attributes that represent others can generate less expenditure of time and financial resources for monitoring cultivated areas. Thus, this study aimed to analyze the spatial distribution and spatial autocorrelation of physical attributes of an Oxisol (Latossolo Vermelho Amarelo, Brazilian Soil Classification System). The evaluated attributes consisted of soil density (SD), total porosity (TP), free porosity (FP), field capacity (FC), permanent wilt point (PW), and total water availability (TW). Semivariogram adjustments and semivariance estimates were performed to characterize the structure and magnitude of the spatial dependence of soil attributes. The attributes were distributed on thematic... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Precision agriculture; Spatial dependence; Geostatistics; Moran index. |
| Ano: 2021 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162021000200255 |
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| Oliveira,Job T. de; Oliveira,Rubens A. de; Furtado Junior,Marconi R.. |
| ABSTRACT This study aimed to investigate relationships between the soil attributes that most affect garlic yield, which can be useful to choose a new area for the growing of this vegetable. We also aimed to study the effects of irrigation deficit at bulb formation stage (cloves) on final garlic quality and yield. The variables evaluated were garlic yield, irrigation, nitrogen, lateral shoot growing, plant water potential, bulb volume, leaf area index, soil electrical conductivity, soil mechanical resistance to penetration, and volumetric soil moisture content. Initially, the Pearson's correlation was estimated for the phenological indexes, and a correlation network was used to graphically express the results and to correct multicollinearity between... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Allium sativum L.; Path analysis; Precision irrigation; Precision agriculture. |
| Ano: 2021 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162021000200215 |
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| Carneiro,Franciele M.; Furlani,Carlos E. A.; Zerbato,Cristiano; Menezes,Patricia C. de; Gírio,Lucas A. da S.. |
| ABSTRACT Active optical sensors have been widely used for the spatial and temporal monitoring of peanut culture because they are accurate, non-destructive methods for rapidly obtaining data. The objective of this study was to determine the optimal stage of crop growth for collecting sensor readings based on correlations between quality indicators. In addition, we compared vegetation indices (Normalized Difference Vegetation Index [NDVI], Normalized Difference Red-Edge Index, [NDRE], and Inverse Ratio Vegetation Index, [IRVI]) by monitoring temporal variability in the peanut crop in order to determine which of them obtained the best reading quality throughout the process. The experiment was performed on the 2016/17 crop in the agricultural area of the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Remote sensing; Arachis hypogaea L.; Control charts; Precision agriculture. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162019000800033 |
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| Ribeiro,Felipe O.; Fernandes,Antonio R.; Matos,Gilson S. B. de; Lindolfo,Marcelo M.; Guedes,Rafael S.; Rodrigues,Graziele R.. |
| ABSTRACT This study aimed to define management zones (MZs) for fertirrigated açaí cultivation, based on spatial variability of the foliar nutrients and productivity data. The work was carried out in an area of 5.75 ha of a 7-year crop, with 80 georeferenced sample points. Fresh fruit productivity and nutrient (N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, and Zn) contents were determined. The average contents of macronutrients were considered adequate for adult açaí plants, and their spatial dependence associated with fruit productivity allowed the representation of their distributions through maps of variability. Through multivariate analysis, three main components were highlighted. These components explained 51.5 % of the total variability of the data, where PC1... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amazon; Management zones; Multivariate analysis; Nutrient contents; Precision agriculture. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000600800 |
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| Roccia,Clerivaldo; Teruel,Bárbara; Alves,Elaine C. de S.; Arnold,Francisco; Bravo-Roger,Leonardo; Moretti,Angelo; Gonçalves,Marcos S.. |
| The aim of this study was to perform an experimental study to evaluate the proper operation distance between the nodes of a wireless sensor network available on the market for different agricultural crops (maize, physic nut, eucalyptus). The experimental data of the network performance offers to farmers and researchers information that might be useful to the sizing and project of the wireless sensor networks in similar situations to those studied. The evaluation showed that the separation of the nodes depends on the type of culture and it is a critical factor to ensure the feasibility of using WSN. In the configuration used, sending packets every 2 seconds, the battery life was about four days. Therefore, the autonomy may be increased with a longer... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Maize (Zea mays L); Physic nut (Jatropha curcas); Eucalyptus (Eucalyptus grandis); Precision agriculture; Zigbee technology. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162012000600018 |
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| Calou,Vinícius B. C.; Teixeira,Adunias dos S.; Moreira,Luis C. J.; Rocha Neto,Odílio C. da; Silva,José A. da. |
| ABSTRACT Unmanned aerial vehicles (UAVs) are a promising tool for technology development and transfer and for the economic success of the agricultural sector. The objective of this study is to assess the validity of biomass estimation in a commercial maize plantation using aerial images obtained by a UAV. The proposed methodology involved analyzing images acquired in scheduled flights, processing orthophoto (georeferenced image) data, evaluating digital terrain elevation models, and assessing the quality of dense point clouds. Data were collected using two cameras, one with a 16-megapixel flat lens and the other with a 12-megapixel fish-eye lens coupled to a UAV, at two flight altitudes (30 and 60 meters) over hybrid maize (AG1051) crop irrigated by center... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Precision agriculture; Structure from Motion; Unmanned aerial vehicles; Zea mays L. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162019000600744 |
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| Beneduzzi,Humberto M.; Souza,Eduardo G.; Bazzi,Claudio L.; Schenatto,Kelyn. |
| ABSTRACT: Optimization of N management is one of the great challenges to be overcome in grain production, as it is directly related to productivity and can also cause environmental damage. Precision agriculture aims to solve this problem by applying nitrogen fertilizer at varying rates. Reflectance sensors are instruments capable of estimating N needs in various crops, including grain crops. However, it is not clear how these sensors perform under varying solar radiation and cloud cover, due to a lack of research on their temporal variability. Thus, this study examined the temporal variability of the NDVI (normalized difference vegetation index), as measured by an active reflectance sensor, in both soybean and wheat crops. The NDVI data were collected... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Precision agriculture; Remote sensing; Vegetation index; NDVI. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162017000400771 |
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| Stocker,Vinícius; Souza,Eduardo G. de; Johann,Jerry A.; Beneduzzi,Humberto M.; Silva,Franciléia de O. e. |
| ABSTRACT The application of nitrogen (N) fertilizer is complex and expensive, so its correct management has financial and environmental benefits. The use of optical proximity sensors is a promising technique. However, the movement of the agricultural machinery or of the person carrying the sensor will result in height differences and/or different tilt and twist angles with respect to the canopy. We considered whether these variations would affect the reflectance measurement. In this study, we took normalized difference vegetation index (NDVI) readings of a wheat canopy, to which 90 kg ha-1 of urea had been applied in stage 5, and observed the NDVI in stages 6, 8 and 10.5. We also tested soybeans, to which 90 kg ha-1 of urea had been applied in stage R1,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Nitrogen fertilization; Precision agriculture; GreenSeeker; NDVI. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162019000800096 |
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| MACHADO,THIAGO M.; LANÇAS,KLÉBER P.. |
| ABSTRACT In Brazil, there are several available models and systems to measure soil compaction; however, the data generated by such equipment have to be processed and interpreted, making the process expensive. Our study aimed to evaluate a prototype of instrumented rods to identify soil compacted layers and control chiseling depth, and compared it to a conventional system at a fixed depth of 0.35 m. In order to compare them, we assessed the following parameters: hourly fuel consumption, operational fuel consumption, drawbar power, average power, average speed, slipping, tractor effective field capacity and response time. Our results showed that mechanical chiseling at variable depths reduced in 26% the operational fuel consumption and increased in 14% the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Precision agriculture; Soil compaction; Chiseling. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162016000400646 |
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| Konopatzki,Marcia R. S.; Souza,Eduardo G.; Nóbrega,Lúcia H. P.; Uribe-Opazo,Miguel A.; Suszek,Grazieli. |
| In the last few years, precision agriculture has become commonly used with many crops, particularly cereals, and there is also interest in precision horticulture. Pear is a seasonal fruit and well appreciated by Brazilian people, although it is mostly imported. Brazilian farmers are nowadays trying to increase pear production. Thus, this research aimed at mapping the yield of pear trees in order to study the spatial variability of yield as well as its comparison with spatial variability of soil and plant attributes. The experimental field had 146 pear trees, variety 'Pêra d'água', distributed on a 1.24 ha. Four harvests were performed according to the fruit ripening and from each tree; only the ripe fruits were harvested. In each harvest, all the fruits... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Precision agriculture; Thematic maps; Horticulture. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162012000200018 |
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| Spagnolo,Roger T.; Rosa,David P. da; Pinho,Marivan da S.; Schiavon,Cheiner S.; Schmechel,Diego K.. |
| ABSTRACT The use of microgranular fertilizers is currently increasing, with low application rates as an obstacle in the mechanization. This study aimed to verify the performance of helical metering mechanisms using microgranular fertilizer. Four different fertilizer-metering mechanisms were tested at two pre-established dose rates (35 and 50 kg ha−1) and seven longitudinal angles (−15°, −10°, −5°, 0°, +5°, +10°, and +15°). The experiment was carried out according to Brazilian standards. The results showed that the longitudinal inclination affects the actual fertilizer dose in all tested metering systems. Metering mechanisms with a helicoid with longitudinal and lateral overflow presented a similar dose, according to the variation of the longitudinal... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Agricultural equipment; Longitudinal inclination; Precision agriculture. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000400481 |
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| Cunha,João P. A. R. Da; Sirqueira Neto,Matheus A.. |
| ABSTRACT: The remotely piloted aircraft (RPA) have great applicability in agriculture. Although it is a technology that has been developed for many years, in the field of agriculture it passed unnoticed for a long time. The high cost of acquisition is still a limiting factor for small and medium-sized farmers. In this way, this study had as objective to develop a low cost RPA for agriculture application. In the present study, the development and the assembly of an RPA prototype of a quadcopter type is presented, consisting of four engines and of vertical propulsion, capable of moving without human intervention, that is, autonomous flight, applied to agriculture and low cost investment. In it was boarded a data control and processing system collected from... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Precision agriculture; Quadcopters; RPA. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162017000601268 |
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| Registros recuperados: 144 | |
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